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

🔗 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.

🔗 Video games 🔗 Film 🔗 Television 🔗 Science Fiction

Black Mirror: Bandersnatch is a 2018 interactive film in the science fiction anthology series Black Mirror. It was written by series creator Charlie Brooker and directed by David Slade. Netflix released the standalone film on 28 December 2018.

In Bandersnatch, viewers make decisions for the main character, the young programmer Stefan Butler (Fionn Whitehead), who is adapting a fantasy choose-your-own-adventure novel into a video game in 1984. Other characters include Mohan Thakur (Asim Chaudhry) and Colin Ritman (Will Poulter), both of whom work at a video game company, Butler's father, Peter (Craig Parkinson), and Butler's therapist, Dr. Haynes (Alice Lowe). The film is based on a planned Imagine Software video game of the same name which went unreleased after the company filed for bankruptcy. It also alludes to Lewis Carroll's own works that feature the bandersnatch creature. A piece of science fiction and horror, Bandersnatch incorporates meta-commentary and rumination on free will.

Brooker and executive producer Annabel Jones were approached by Netflix about making an interactive film in May 2017, during which time Netflix had several interactive projects for children underway. Difficulty in writing the highly non-linear script led to the creation of a bespoke program called Branch Manager for Netflix; the unique nature of the content required adaptations in the platform's use of cache memory. Filming and production took longer than for typical Black Mirror episodes, resulting in the show's fifth series being delayed. A quickly-deleted tweet from a Netflix account about the release of Bandersnatch led to widespread media speculation throughout December which Netflix declined to comment on. The trailer for Bandersnatch was released on 27 December 2018, a day before the film was released. Critical reception for the film was generally positive, though some found the interactive nature to be too gimmicky for a proper Black Mirror narrative. In 2019, the episode won two Emmy Awards, including the Outstanding Television Movie award.

🔗 Physics

The Magdeburg hemispheres are a pair of large copper hemispheres, with mating rims. They were used to demonstrate the power of atmospheric pressure. When the rims were sealed with grease and the air was pumped out, the sphere contained a vacuum and could not be pulled apart by teams of horses. The Magdeburg hemispheres were invented by German scientist and mayor of Magdeburg, Otto von Guericke, to demonstrate the air pump that he had invented, and the concept of atmospheric pressure. The first artificial vacuum had been produced a few years earlier by Evangelista Torricelli, and had inspired Guericke to design the world's first vacuum pump, which consisted of a piston and cylinder with one-way flap valves. The hemispheres became popular in physics lectures as an illustration of the strength of air pressure, and are still used in education. A pair of the original hemispheres are preserved in the Deutsches Museum in Munich.

🔗 Computing

Fog computing or fog networking, also known as fogging, is an architecture that uses edge devices to carry out a substantial amount of computation, storage, and communication locally and routed over the internet backbone.

🔗 Professional sound production

The phonautograph is the earliest known device for recording sound. Previously, tracings had been obtained of the sound-producing vibratory motions of tuning forks and other objects by physical contact with them, but not of actual sound waves as they propagated through air or other media. Invented by Frenchman Édouard-Léon Scott de Martinville, it was patented on March 25, 1857. It transcribed sound waves as undulations or other deviations in a line traced on smoke-blackened paper or glass. Intended solely as a laboratory instrument for the study of acoustics, it could be used to visually study and measure the amplitude envelopes and waveforms of speech and other sounds, or to determine the frequency of a given musical pitch by comparison with a simultaneously recorded reference frequency.

Apparently, it did not occur to anyone before the 1870s that the recordings, called phonautograms, contained enough information about the sound that they could, in theory, be used to recreate it. Because the phonautogram tracing was an insubstantial two-dimensional line, direct physical playback was impossible in any case.

Several phonautograms recorded before 1861 were successfully played as sound in 2008 by optically scanning them and using a computer to process the scans into digital audio files.

🔗 Computing

LOOP is a programming language designed by Uwe Schöning, along with GOTO and WHILE. The only operations supported in the language are assignment, addition and looping.

The key property of the LOOP language is that the functions it can compute are exactly the primitive recursive functions.

🔗 Germany

The Nazi book burnings were a campaign conducted by the German Student Union (the "DSt") to ceremonially burn books in Nazi Germany and Austria in the 1930s. The books targeted for burning were those viewed as being subversive or as representing ideologies opposed to Nazism. These included books written by Jewish, pacifist, religious, liberal, anarchist, socialist, communist, and sexologist authors among others. The first books burned were those of Karl Marx and Karl Kautsky.

🔗 Australia 🔗 Buses 🔗 Australia/Adelaide

The O-Bahn Busway is a guided busway that is part of the bus rapid transit system servicing the northeastern suburbs of Adelaide, South Australia. The O-Bahn system was conceived by Daimler-Benz to enable buses to avoid traffic congestion by sharing tram tunnels in the German city of Essen.

Adelaide's O-Bahn was introduced in 1986 to service the city's rapidly expanding north-eastern suburbs, replacing an earlier plan for a tramway extension. The O-Bahn provides specially built track, combining elements of both bus and rail systems. Adelaide's track is 12 kilometres (7.5 mi) long and includes three interchanges at Klemzig, Paradise and Tea Tree Plaza. Interchanges allow buses to enter and exit the busway and to continue on suburban routes, avoiding the need for passengers to transfer to another bus to continue their journey. Buses can travel at a maximum speed of 100 km/h (60 mph), but are now restricted to 85 km/h (53 mph). As of 2015, the busway carries approximately 31,000 people per weekday. An additional section including a 670-metre (2,200 ft) tunnel opened in 2017 at the city end to reduce the number of congested intersections buses must traverse to enter the Adelaide city centre.

The development of the O-Bahn busway led to the development of the Torrens Linear Park from a run-down urban drain into an attractive public open space. It has also triggered urban development around the north-eastern terminus at Modbury.

🔗 Comics

Potrzebie (; Polish pronunciation: [pɔtˈʂɛbʲe] dative/locative of potrzeba, "a need") is a Polish word popularized by its non sequitur use as a running gag in the early issues of Mad not long after the comic book began in 1952.

🔗 Computing 🔗 Computer science 🔗 Biology 🔗 Chemistry 🔗 Genetics

DNA computing is a branch of computing which uses DNA, biochemistry, and molecular biology hardware, instead of the traditional silicon-based computer technologies. Research and development in this area concerns theory, experiments, and applications of DNA computing. The term "molectronics" has sometimes been used, but this term has already been used for an earlier technology, a then-unsuccessful rival of the first integrated circuits; this term has also been used more generally, for molecular-scale electronic technology.