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🔗 Computing 🔗 Computer science 🔗 Software 🔗 Software/Computing 🔗 Project-independent assessment

A cross compiler is a compiler capable of creating executable code for a platform other than the one on which the compiler is running. For example, a compiler that runs on a PC but generates code that runs on Android devices is a cross compiler.

A cross compiler is useful to compile code for multiple platforms from one development host. Direct compilation on the target platform might be infeasible, for example on embedded systems with limited computing resources.

Cross compilers are distinct from source-to-source compilers. A cross compiler is for cross-platform software generation of machine code, while a source-to-source compiler translates from one coding language to another in text code. Both are programming tools.

🔗 Video games

42 is a private, nonprofit and tuition-free computer programming school created and funded by French billionaire Xavier Niel (founder of the telecommunication company Illiad) with several partners including Nicolas Sadirac (previous director-general of the Epitech school in France), Kwame Yamgnane and Florian Bucher (former executives of Epitech). The school was first opened in Paris in 2013.

Out of more than 80,000 candidates in France, 3,000 were selected to complete a four-week intensive computer programming bootcamp called piscine (swimming-pool). Any person older than 18 can register for the piscine after completing the logical reasoning tests on the website.

The school does not have any professors, and is open 24/7. The training is inspired by new modern ways to teach which include peer-to-peer pedagogy and project-based learning. The School has been endorsed by many high-profile people in Silicon Valley including Evan Spiegel the co-founder and CEO of Snapchat, Keyvon Beykpour the co-founder and CEO of Periscope, Stewart Butterfield the co-founder and CEO of Slack, Brian Chesky the co-founder and CEO of Airbnb, Tony Fadell the founder and CEO of Nest Labs, Jack Dorsey the co-Founder and CEO of Twitter, Paul Graham, venture capitalist and co-Founder of Y Combinator, Bill Gurley venture capitalist and general partner at Benchmark.

The school is a non-profit organization and is entirely free, being funded by billionaire Xavier Niel with hundreds of millions of dollars. All the intellectual property belongs to the students. 42 Silicon Valley is the American campus of 42 chartered as a public-benefit nonprofit corporation in the State of California and has been created and funded by the same team from France, in addition to a new partner, the chief operating officer of the American school and former 42 Paris student Brittany Bir. 42 Silicon Valley opened in summer 2016 in Fremont, California in the San Francisco Bay Area.

42's name is a reference to the science fiction book The Hitchhiker's Guide to the Galaxy written by British author Douglas Adams: in the book 42 is the Answer to the Ultimate Question of Life, the Universe, and Everything.

In addition to the two official campuses in Paris, France and Fremont, California, the school model was adopted in Lyon, Reims, and Mulhouse, France, as well as in Romania, South Africa, Ukraine, Bulgaria, Moldova, Belgium, Russia, Morocco, the Netherlands, Indonesia, and Finland with the help and support of 42.

🔗 Writing systems

A lipogram (from Ancient Greek: λειπογράμματος, leipográmmatos, "leaving out a letter") is a kind of constrained writing or word game consisting of writing paragraphs or longer works in which a particular letter or group of letters is avoided. Extended Ancient Greek texts avoiding the letter sigma are the earliest examples of lipograms.

Writing a lipogram may be a trivial task when avoiding uncommon letters like Z, J, Q, or X, but it is much more challenging to avoid common letters like E, T, or A in the English language, as the author must omit many ordinary words. Grammatically meaningful and smooth-flowing lipograms can be difficult to compose. Identifying lipograms can also be problematic, as there is always the possibility that a given piece of writing in any language may be unintentionally lipogrammatic. For example, Poe's poem The Raven contains no Z, but there is no evidence that this was intentional.

A pangrammatic lipogram is a text that uses every letter of the alphabet except one. For example, "The quick brown fox jumped over the lazy dog" omits the letter S, which the usual pangram includes by using the word jumps.

🔗 Germany 🔗 Astronomy 🔗 Archaeology 🔗 Visual arts

The Nebra sky disk is a bronze disk of around 30 centimeters (11 ³⁄₄ in) diameter and a weight of 2.2 kilograms (4.9 lb), having a blue-green patina and inlaid with gold symbols. These symbols are interpreted generally as the Sun or full moon, a lunar crescent, and stars (including a cluster of seven interpreted as the Pleiades). Two golden arcs along the sides, interpreted to mark the angle between the solstices, were added later. A final addition was another arc at the bottom surrounded with multiple strokes (of uncertain meaning, variously interpreted as a Solar Barge with numerous oars, the Milky Way, or a rainbow).

The disk is attributed to a site in present-day Germany near Nebra, Saxony-Anhalt, and dated by Archaeological association to c. 1600 BC. Researchers suggest the disk is an artifact of the Bronze Age Unetice culture.

The style in which the disk is executed was unlike any artistic style then known from the period, with the result that the object was initially suspected of being a forgery, but is now widely accepted as authentic.

The Nebra sky disk features the oldest concrete depiction of the cosmos yet known from anywhere in the world. In June 2013 it was included in the UNESCO Memory of the World Register and termed "one of the most important archaeological finds of the twentieth century."

🔗 Technology 🔗 Military history 🔗 Military history/Military science, technology, and theory 🔗 Military history/Maritime warfare

Communication with submarines is a field within military communications that presents technical challenges and requires specialized technology. Because radio waves do not travel well through good electrical conductors like salt water, submerged submarines are cut off from radio communication with their command authorities at ordinary radio frequencies. Submarines can surface and raise an antenna above the sea level, then use ordinary radio transmissions, however this makes them vulnerable to detection by anti-submarine warfare forces. Early submarines during World War II mostly traveled on the surface because of their limited underwater speed and endurance; they dove mainly to evade immediate threats. During the Cold War, however, nuclear-powered submarines were developed that could stay submerged for months. Transmitting messages to these submarines is an active area of research. Very low frequency (VLF) radio waves can penetrate seawater a few hundred feet, and many navies use powerful VLF transmitters for submarine communications. A few nations have built transmitters which use extremely low frequency (ELF) radio waves, which can penetrate seawater to reach submarines at operating depths, but these require huge antennas. Other techniques that have been used include sonar and blue lasers.

🔗 Companies 🔗 Lists 🔗 Disney

The following is a list of assets owned and operated by The Walt Disney Company, unless otherwise indicated.

🔗 Russia 🔗 Russia/technology and engineering in Russia 🔗 Spaceflight 🔗 Spaceflight/space stations working group

The terms Androgynous Peripheral Attach System (APAS), Androgynous Peripheral Assembly System (APAS) and Androgynous Peripheral Docking System (APDS) are used interchangeably to describe a Russian family of spacecraft docking mechanisms, and are also sometimes used as generic names for any docking system in that family. A system similar to APAS-89/95 is used by the Chinese Shenzhou spacecraft.

🔗 Physics

In stellar physics, the Jeans instability causes the collapse of interstellar gas clouds and subsequent star formation, named after James Jeans. It occurs when the internal gas pressure is not strong enough to prevent gravitational collapse of a region filled with matter. For stability, the cloud must be in hydrostatic equilibrium, which in case of a spherical cloud translates to:

${\displaystyle {\frac {dp}{dr}}=-{\frac {G\rho (r)M_{enc}(r)}{r^{2}}}}$,

where ${\displaystyle M_{enc}(r)}$ is the enclosed mass, ${\displaystyle p}$ is the pressure, ${\displaystyle \rho (r)}$ is the density of the gas (at radius ${\displaystyle r}$), ${\displaystyle G}$ is the gravitational constant, and ${\displaystyle r}$ is the radius. The equilibrium is stable if small perturbations are damped and unstable if they are amplified. In general, the cloud is unstable if it is either very massive at a given temperature or very cool at a given mass; under these circumstances, the gas pressure cannot overcome gravity, and the cloud will collapse.

🔗 Soviet Union 🔗 Russia 🔗 Russia/language and literature of Russia 🔗 Russia/history of Russia 🔗 Georgia (country)

Before he became a Bolshevik revolutionary and the leader of the Soviet Union, Joseph Stalin was a promising poet.

🔗 United States 🔗 Biography 🔗 Biography/science and academia 🔗 Astronomy 🔗 United States/Arizona 🔗 Astronomy/Solar System

Robert Burnham Jr. (June 16, 1931 – March 20, 1993) was an American astronomer, best known for writing the classic three-volume Burnham's Celestial Handbook. He is the discoverer of numerous asteroids including the Mars crossing asteroid 3397 Leyla, as well as six comets.

Burnham's late years were tragic; he died destitute and alone. However, he is remembered by a generation of deep sky observers for his unique contribution to astronomy, the Celestial Handbook. The main-belt asteroid 3467 Bernheim was named in his honor.