Random Articles (Page 2)

Have a deep view into what people are curious about.

πŸ”— Ubuntu Philosophy

πŸ”— Human rights πŸ”— Africa πŸ”— Philosophy πŸ”— Philosophy/Ethics

Ubuntu (Zulu pronunciation:Β [ΓΉΙ“ΓΊntΚΌΓΉ]) is a Nguni Bantu term meaning "humanity." It is often translated as "I am because we are," or "humanity towards others," or in Xhosa, "umntu ngumntu ngabantu" but is often used in a more philosophical sense to mean "the belief in a universal bond of sharing that connects all humanity."

In Southern Africa, it has come to be used as a contested term for a kind of humanist philosophy, ethic, or ideology, also known as Ubuntuism propagated in the Africanisation (transition to majority rule) process of these countries during the 1980s and 1990s.

Since the transition to democracy in South Africa with the Nelson Mandela presidency in 1994, the term has become more widely known outside of Southern Africa, notably popularised to English-language readers through the ubuntu theology of Desmond Tutu. Tutu was the chairman of the South African Truth and Reconciliation Commission (TRC), and many have argued that ubuntu was a formative influence on the TRC.

Discussed on

πŸ”— Hyperparasite

πŸ”— Biology πŸ”— Insects πŸ”— Ecology

A hyperparasite, also known as a metaparasite is a parasite whose host, often an insect, is also a parasite, often specifically a parasitoid. Hyperparasites are found mainly among the wasp-waisted Apocrita within the Hymenoptera, and in two other insect orders, the Diptera (true flies) and Coleoptera (beetles). Seventeen families in Hymenoptera and a few species of Diptera and Coleoptera are hyperparasitic. Hyperparasitism developed from primary parasitism, which evolved in the Jurassic period in the Hymenoptera. Hyperparasitism intrigues entomologists because of its multidisciplinary relationship to evolution, ecology, behavior, biological control, taxonomy, and mathematical models.

Discussed on

πŸ”— Flux pinning

πŸ”— Physics

Flux pinning is the phenomenon where a superconductor is pinned in space above a magnet. The superconductor must be a type-II superconductor because type-I superconductors cannot be penetrated by magnetic fields. The act of magnetic penetration is what makes flux pinning possible. At higher magnetic fields (above Hc1 and below Hc2) the superconductor allows magnetic flux to enter in quantized packets surrounded by a superconducting current vortex (see Quantum vortex). These sites of penetration are known as flux tubes. The number of flux tubes per unit area is proportional to the magnetic field with a constant of proportionality equal to the magnetic flux quantum. On a simple 76 millimeter diameter, 1-micrometer thick disk, next to a magnetic field of 28 kA/m, there are approximately 100 billion flux tubes that hold 70,000 times the superconductor's weight. At lower temperatures the flux tubes are pinned in place and cannot move. This pinning is what holds the superconductor in place thereby allowing it to levitate. This phenomenon is closely related to the Meissner effect, though with one crucial difference β€” the Meissner effect shields the superconductor from all magnetic fields causing repulsion, unlike the pinned state of the superconductor disk which pins flux, and the superconductor in place.

πŸ”— Lycurgus Cup

πŸ”— London πŸ”— British Museum πŸ”— Classical Greece and Rome πŸ”— History of Science πŸ”— Archaeology πŸ”— Visual arts πŸ”— 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.

Discussed on

πŸ”— PainStation

πŸ”— Video games

Painstation is an art object and arcade game based on Pong developed by the artists' group "/////////fur//// art entertainment interfaces", with pain feedback.

Discussed on

πŸ”— Motorola 6800

πŸ”— Computing πŸ”— Computing/Computer hardware

The 6800 ("sixty-eight hundred") is an 8-bit microprocessor designed and first manufactured by Motorola in 1974. The MC6800 microprocessor was part of the M6800 Microcomputer System that also included serial and parallel interface ICs, RAM, ROM and other support chips. A significant design feature was that the M6800 family of ICs required only a single five-volt power supply at a time when most other microprocessors required three voltages. The M6800 Microcomputer System was announced in March 1974 and was in full production by the end of that year.

The 6800 has a 16-bit address bus that can directly access 64Β KB of memory and an 8-bit bi-directional data bus. It has 72 instructions with seven addressing modes for a total of 197 opcodes. The original MC6800 could have a clock frequency of up to 1Β MHz. Later versions had a maximum clock frequency of 2Β MHz.

In addition to the ICs, Motorola also provided a complete assembly language development system. The customer could use the software on a remote timeshare computer or on an in-house minicomputer system. The Motorola EXORciser was a desktop computer built with the M6800 ICs that could be used for prototyping and debugging new designs. An expansive documentation package included datasheets on all ICs, two assembly language programming manuals, and a 700-page application manual that showed how to design a point-of-sale terminal (a computerized cash register) around the 6800.

The 6800 was popular in computer peripherals, test equipment applications and point-of-sale terminals. It also found use in arcade games and pinball machines. The MC6802, introduced in 1977, included 128 bytes of RAM and an internal clock oscillator on chip. The MC6801 and MC6805 included RAM, ROM and I/O on a single chip and were popular in automotive applications. The Motorola 6809 was an updated compatible design.

Discussed on

πŸ”— Quine

πŸ”— Computing

A quine is a computer program which takes no input and produces a copy of its own source code as its only output. The standard terms for these programs in the computability theory and computer science literature are "self-replicating programs", "self-reproducing programs", and "self-copying programs".

A quine is a fixed point of an execution environment, when the execution environment is viewed as a function transforming programs into their outputs. Quines are possible in any Turing complete programming language, as a direct consequence of Kleene's recursion theorem. For amusement, programmers sometimes attempt to develop the shortest possible quine in any given programming language.

The name "quine" was coined by Douglas Hofstadter, in his popular science book GΓΆdel, Escher, Bach, in honor of philosopher Willard Van Orman Quine (1908–2000), who made an extensive study of indirect self-reference, and in particular for the following paradox-producing expression, known as Quine's paradox:

"Yields falsehood when preceded by its quotation" yields falsehood when preceded by its quotation.

Discussed on

πŸ”— Electrochemical RAM

πŸ”— Technology πŸ”— Computing πŸ”— Electronics πŸ”— Engineering

Electrochemical Random-Access Memory (ECRAM) is a type of non-volatile memory (NVM) with multiple levels per cell (MLC) designed for deep learning analog acceleration. An ECRAM cell is a three-terminal device composed of a conductive channel, an insulating electrolyte, an ionic reservoir, and metal contacts. The resistance of the channel is modulated by ionic exchange at the interface between the channel and the electrolyte upon application of an electric field. The charge-transfer process allows both for state retention in the absence of applied power, and for programming of multiple distinct levels, both differentiating ECRAM operation from that of a field-effect transistor (FET). The write operation is deterministic and can result in symmetrical potentiation and depression, making ECRAM arrays attractive for acting as artificial synaptic weights in physical implementations of artificial neural networks (ANN). The technological challenges include open circuit potential (OCP) and semiconductor foundry compatibility associated with energy materials. Universities, government laboratories, and corporate research teams have contributed to the development of ECRAM for analog computing. Notably, Sandia National Laboratories designed a lithium-based cell inspired by solid-state battery materials, Stanford University built an organic proton-based cell, and International Business Machines (IBM) demonstrated in-memory selector-free parallel programming for a logistic regression task in an array of metal-oxide ECRAM designed for insertion in the back end of line (BEOL). In 2022, researchers at Massachusetts Institute of Technology built an inorganic, CMOS-compatible protonic technology that achieved near-ideal modulation characteristics using nanosecond fast pulses

πŸ”— Russian Domesticated Red Fox

πŸ”— Russia πŸ”— Dogs πŸ”— Russia/science and education in Russia πŸ”— Genetics πŸ”— Russia/physical geography of Russia πŸ”— Russia/economy of Russia

The Russian domesticated red fox is a form of the wild red fox (Vulpes vulpes) which has been domesticated to an extent, under laboratory conditions. They are the result of an experiment which was designed to demonstrate the power of selective breeding to transform species, as described by Charles Darwin in On the Origin of Species. The experiment was purposely designed to replicate the process that had produced dogs from wolves, by recording the changes in foxes, when in each generation only the most tame foxes were allowed to breed. In short order, the descendant foxes became tamer and more dog-like in their behavior.

The program was started in 1959 in the Soviet Union by zoologist Dmitry Belyayev and it has been in continuous operation since. Today, the experiment is under the supervision of Lyudmila Trut, in Russia, at the Institute of Cytology and Genetics in Novosibirsk.

Discussed on

πŸ”— Alexey Chervonenkis found dead

πŸ”— Biography πŸ”— Russia πŸ”— Statistics πŸ”— Biography/science and academia πŸ”— Russia/science and education in Russia

Alexey Yakovlevich Chervonenkis (Russian: АлСксСй Π―ΠΊΠΎΠ²Π»Π΅Π²ΠΈΡ‡ ЧСрвонСнкис; 7 September 1938 – 22 September 2014) was a Soviet and Russian mathematician, and, with Vladimir Vapnik, was one of the main developers of the Vapnik–Chervonenkis theory, also known as the "fundamental theory of learning" an important part of computational learning theory. Chervonenkis held joint appointments with the Russian Academy of Sciences and Royal Holloway, University of London.

Alexey Chervonenkis got lost in Losiny Ostrov National Park on 22 September 2014, and later during a search operation was found dead near Mytishchi, a suburb of Moscow. He had died of hypothermia.

Discussed on