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🔗 Computing 🔗 Computing/Software

Norton Commander (NC) is a discontinued prototypical orthodox file manager (OFM), written by John Socha and released by Peter Norton Computing (later acquired in 1990 by the Symantec corporation). NC provides a text-based user interface for managing files on top of MS-DOS. It was officially produced between 1986 and 1998. The last MS-DOS version of Norton Commander, 5.51, was released on July 1, 1998.

A related product, Norton Desktop, a graphical shell for MS-DOS and Windows, succeeded Norton Commander. It came in two variants, Norton Desktop for DOS and Norton Desktop for Windows.

🔗 Environment 🔗 Law 🔗 Backpacking

The freedom to roam, or "everyman's right", is the general public's right to access certain public or privately owned land, lakes, and rivers for recreation and exercise. The right is sometimes called the right of public access to the wilderness or the "right to roam".

In Scotland, Finland, Iceland, Norway, Sweden, Estonia, Latvia, Lithuania, Austria, Czech Republic and Switzerland, the freedom to roam takes the form of general public rights which are sometimes codified in law. The access is ancient in parts of Northern Europe and has been regarded as sufficiently basic that it was not formalised in law until modern times. However, the right usually does not include any substantial economic exploitation, such as hunting or logging, or disruptive activities, such as making fires and driving offroad vehicles.

In England and Wales public access rights apply only to certain categories of mainly uncultivated land.

🔗 Mathematics

Pentagramma mirificum (Latin for miraculous pentagram) is a star polygon on a sphere, composed of five great circle arcs, all of whose internal angles are right angles. This shape was described by John Napier in his 1614 book Mirifici logarithmorum canonis descriptio (Description of the wonderful rule of logarithms) along with rules that link the values of trigonometric functions of five parts of a right spherical triangle (two angles and three sides). The properties of pentagramma mirificum were studied, among others, by Carl Friedrich Gauss.

🔗 Trains

In rail transportation, a rolling highway or rolling road is a form of combined transport involving the conveying of road trucks by rail, referred to as Ro-La trains. The concept is a form of piggyback transportation.

The technical challenges to implement rolling highways vary from region to region. In North America, the loading gauge is often high enough to accommodate double stack containers, so the height of a semi-trailer on a flatcar is no issue. However, in Europe, except for purpose built lines such as the Channel Tunnel or the Gotthard Base Tunnel, the loading gauge height is much smaller, and it is necessary to transport the trailers with the tires about 30 cm (11.81 in) above the rails, so the trailers cannot be simply parked on the surface of a flat car above the wagon wheels or bogies. Making the wagon wheels smaller limits the maximum speed, so many designs allow the trailer to be transported with its wheels lower than the rail wagon wheels. An early approach in France was the Kangourou wagon with modified trailers. This technology did not survive, due to the market resistance to modified trailers. Today, three designs for these special wagons are in commercial service, "Modalohr", "CargoBeamer" and "Niederflurwagen" .

During a rolling-highway journey, if the drivers accompany the trailer, they are accommodated in a passenger car or a sleeping car. At both ends of the rail link there are purpose-built terminals that allow the train to be easily loaded and unloaded.

🔗 History of Science 🔗 Tree of Life

The species problem is the set of questions that arises when biologists attempt to define what a species is. Such a definition is called a species concept; there are at least 26 recognized species concepts. A species concept that works well for sexually reproducing organisms such as birds is useless for species that reproduce asexually, such as bacteria. The scientific study of the species problem has been called microtaxonomy.

One common, but sometimes difficult, question is how best to decide which species an organism belongs to, because reproductively isolated groups may not be readily recognizable, and cryptic species may be present. There is a continuum from reproductive isolation with no interbreeding, to panmixis, unlimited interbreeding. Populations can move forward or backwards along this continuum, at any point meeting the criteria for one or another species concept, and failing others.

Many of the debates on species touch on philosophical issues, such as nominalism and realism, and on issues of language and cognition.

The current meaning of the phrase "species problem" is quite different from what Charles Darwin and others meant by it during the 19th and early 20th centuries. For Darwin, the species problem was the question of how new species arose. Darwin was however one of the first people to question how well-defined species are, given that they constantly change.

🔗 Biography 🔗 Biography/arts and entertainment 🔗 Japan 🔗 Photography 🔗 Japan/History 🔗 Japan/Science and technology 🔗 Photography/History of photography 🔗 Japan/Biography

Ichiki Shirō (市来 四郎, January 29, 1828 – February 12, 1903) was a pioneering Japanese photographer.

Ichiki was born in Satsuma Province (now Kagoshima Prefecture) in Kyūshū on 24 December 1828. He excelled in the study of topics related to gunpowder production in the Takashima-ryū school of gunnery. This talent was recognized by Shimazu Nariakira, the daimyō of Satsuma, who selected Ichiki to be one of his personal retainers. In 1848, Shimazu obtained the first daguerreotype camera ever imported into Japan. Ever fascinated by Western technology, he ordered his retainers (including Ichiki) to study it and produce working photographs. Due to the limitations of the lens used and the lack of formal training, it took many years for a quality photograph to be created, but on 17 September 1857, Ichiki created a portrait of Shimazu in formal attire. All this was recorded in detail in Ichiki's memoirs, which were compiled in 1884.

This photograph became an object of worship in Terukuni jinja after Shimazu's death, but it later went missing. Lost for a century, the daguerreotype was discovered in a warehouse in 1975 and was later determined to be the oldest daguerreotype in existence that was created by a Japanese photographer. For this reason, it was designated an Important Cultural Property by the government of Japan in 1999, the first photograph so designated.

🔗 Biography 🔗 Economics 🔗 University of Cambridge

Piero Sraffa (5 August 1898 – 3 September 1983) was an influential Italian economist who served as lecturer of economics at the University of Cambridge. His book Production of Commodities by Means of Commodities is taken as founding the neo-Ricardian school of economics.

🔗 Mathematics 🔗 Archaeology

The Ishango bone is a bone tool and possible mathematical object, dated to the Upper Paleolithic era. It is a dark brown length of bone, the fibula of a baboon, with a sharp piece of quartz affixed to one end, perhaps for engraving. It is thought by some to be a tally stick, as it has a series of what has been interpreted as tally marks carved in three columns running the length of the tool, though it has also been suggested that the scratches might have been to create a better grip on the handle or for some other non-mathematical reason. Others argue that the marks on the object are non-random and that it was likely a kind of counting tool and used to perform simple mathematical procedures.

🔗 Psychology 🔗 Sexology and sexuality 🔗 Evolutionary biology

The sexy son hypothesis in evolutionary biology and sexual selection, proposed by Patrick J. Weatherhead and Raleigh J. Robertson of Queen's University in Kingston, Ontario in 1979, states that a female's ideal mate choice among potential mates is one whose genes will produce males with the best chance of reproductive success. This implies that other benefits the father can offer the mother or offspring are less relevant than they may appear, including his capacity as a parental caregiver, territory and any nuptial gifts. Fisher's principle means that the sex ratio (except in certain eusocial insects) is always near 1:1 between males and females, yet what matters most are her "sexy sons'" future breeding successes, more likely if they have a promiscuous father, in creating large numbers of offspring carrying copies of her genes. This sexual selection hypothesis has been researched in species such as the European pied flycatcher.

🔗 Astronomy 🔗 Astronomy/Astronomical objects

Wolf 359 is a red dwarf star located in the constellation Leo, near the ecliptic. At a distance of approximately 7.9 light years from Earth, it has an apparent magnitude of 13.54 and can only be seen with a large telescope. Wolf 359 is one of the nearest stars to the Sun; only the Alpha Centauri system (including Proxima Centauri), Barnard's Star and the brown dwarfs Luhman 16 and WISE 0855−0714 are known to be closer. Its proximity to Earth has led to its mention in several works of fiction.

Wolf 359 is one of the faintest and lowest-mass stars known. At the light-emitting layer called the photosphere, it has a temperature of about 2,800 K, which is low enough for chemical compounds to form and survive. The absorption lines of compounds such as water and titanium(II) oxide have been observed in the spectrum. The surface has a magnetic field that is stronger than the average magnetic field on the Sun. As a result of magnetic activity caused by convection, Wolf 359 is a flare star that can undergo sudden increases in luminosity for several minutes. These flares emit strong bursts of X-ray and gamma ray radiation that have been observed by space telescopes. Wolf 359 is a relatively young star with an age of less than a billion years. Two planetary companions are suspected but as yet no debris disks have been unmasked.