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

🔗 Computing 🔗 Mathematics

Codd's cellular automaton is a cellular automaton (CA) devised by the British computer scientist Edgar F. Codd in 1968. It was designed to recreate the computation- and construction-universality of von Neumann's CA but with fewer states: 8 instead of 29. Codd showed that it was possible to make a self-reproducing machine in his CA, in a similar way to von Neumann's universal constructor, but never gave a complete implementation.

🔗 Film 🔗 Film/Japanese cinema

Ornamental Hairpin (簪, Kanzashi) is a 1941 Japanese comedy-drama film written and directed by Hiroshi Shimizu. It is based on the short story Yottsu no yubune (四つの湯槽, lit. "The four bathtubs") by Masuji Ibuse.

🔗 Politics 🔗 Socialism 🔗 Chicago 🔗 Holidays 🔗 Organized Labour

International Workers' Day, also called Labour Day in some countries and often referred to as May Day, is a celebration of labourers and the working classes that is promoted by the international labour movement and occurs every year on 1 May, or the first Monday in May.

Traditionally, 1 May is the date of the European spring festival of May Day. The International Workers Congress held in Paris in 1889 established the Second International for labor, socialist, and Marxist parties. It adopted a resolution for a "great international demonstration" in support of working-class demands for the eight-hour day. The date was chosen by the American Federation of Labor to commemorate a general strike in the United States, which had begun on 1 May 1886 and culminated in the Haymarket affair on 4 May. The demonstration subsequently became a yearly event. The 1904 Sixth Conference of the Second International, called on "all Social Democratic Party organisations and trade unions of all countries to demonstrate energetically on the First of May for the legal establishment of the eight-hour day, for the class demands of the proletariat, and for universal peace".

The 1st of May, or first Monday in May, is a national public holiday in many countries, in most cases known as "International Workers' Day" or a similar name. Some countries celebrate a Labour Day on other dates significant to them, such as the United States and Canada, which celebrate Labor Day on the first Monday of September. In 1955, the Catholic Church dedicated 1 May to "Saint Joseph the Worker". Saint Joseph is the patron saint of workers and craftsmen, among others.

Wikipedia offers free copies of all available content to interested users. These databases can be used for mirroring, personal use, informal backups, offline use or database queries (such as for Wikipedia:Maintenance). All text content is licensed under the Creative Commons Attribution-ShareAlike 4.0 License (CC-BY-SA), and most is additionally licensed under the GNU Free Documentation License (GFDL). Images and other files are available under different terms, as detailed on their description pages. For our advice about complying with these licenses, see Wikipedia:Copyrights.

Some of the many ways to read Wikipedia while offline:

• Kiwix: (§ Kiwix) – index of images (2024)
• XOWA: (§ XOWA) – index of images (2015)
• WikiTaxi: § WikiTaxi (for Windows)
• aarddict: § Aard Dictionary / Aard 2
• BzReader: § BzReader and MzReader (for Windows)
• WikiFilter: § WikiFilter
• Wikipedia on rockbox: § Wikiviewer for Rockbox
• Selected Wikipedia articles as a printed document: Help:Printing

Some of them are mobile applications – see "List of Wikipedia mobile applications".

🔗 Germany 🔗 Trains 🔗 Trains/Rail transport in Germany

The Breitspurbahn (German pronunciation: [ˈbʁaɪtʃpuːɐ̯baːn], transl. broad-gauge railway) was a railway system planned and partly surveyed by Nazi Germany. Its track gauge – the distance between the two running rails – was to be 3000 mm (9 ft 10+1⁄8 in), more than twice that of the 1435 mm (4 ft 8+1⁄2 in) standard gauge used in western Europe. The railway was intended initially to run between major cities of the Greater Germanic Reich (the regime's expanded Germany) and neighbouring states.

🔗 Environment 🔗 Books 🔗 Futures studies 🔗 Molecular Biology 🔗 Molecular Biology/Genetics

The Population Bomb is a 1968 book co-authored by former Stanford University professor Paul R. Ehrlich and former Stanford senior researcher in conservation biology Anne H. Ehrlich. From the opening page, it predicted worldwide famines due to overpopulation, as well as other major societal upheavals, and advocated immediate action to limit population growth. Fears of a "population explosion" existed in the mid-20th century baby boom years, but the book and its authors brought the idea to an even wider audience.

The book has been criticized since its publication for an alarmist tone, and over the subsequent decades, for inaccurate assertions and failed predictions. For instance, regional famines have occurred since the publication of the book, but not world famines. The Ehrlichs themselves still stand by the book despite the flaws identified by its critics, with Paul stating in 2009 that "perhaps the most serious flaw in The Bomb was that it was much too optimistic about the future," despite having predicted catastrophic global famines that never came to pass. They believe that it achieved their goals because "it alerted people to the importance of environmental issues and brought human numbers into the debate on the human future."

🔗 Espionage 🔗 Germany 🔗 Politics 🔗 Psychology 🔗 Socialism 🔗 Germany/GDR

Zersetzung (pronounced [t͡sɛɐ̯ˈzɛt͡sʊŋ] , German for "decomposition" and "disruption") was a psychological warfare technique used by the Ministry for State Security (Stasi) to repress political opponents in East Germany during the 1970s and 1980s. Zersetzung served to combat alleged and actual dissidents through covert means, using secret methods of abusive control and psychological manipulation to prevent anti-government activities. Among the defining features of it was the widespread use of offensive counterespionage methods as a means of repression. People were commonly targeted on a pre-emptive and preventive basis, to limit or stop activities of political dissent and cultural incorrectness that they may have gone on to perform, and not on the basis of crimes they had actually committed. Zersetzung methods were designed to break down, undermine, and paralyze people behind "a facade of social normality" in a form of "silent repression".

Erich Honecker's succession to Walter Ulbricht as First Secretary of the Socialist Unity Party of Germany (SED) in May 1971 saw an evolution of "operational procedures" (Operative Vorgänge) conducted by Stasi away from the overt terror of the Ulbricht era towards what came to be known as Zersetzung ("Anwendung von Maßnahmen der Zersetzung"), which was formalized by Directive No. 1/76 on the Development and Revision of Operational Procedures in January 1976. The Stasi used operational psychology and its extensive network of between 170,000 and over 500,000 informal collaborators (inoffizielle Mitarbeiter) to launch personalized psychological attacks against targets to damage their mental health and lower chances of a "hostile action" against the state. Among the collaborators were youths as young as 14 years of age.

The use of Zersetzung is well documented due to Stasi files published after the Berlin Wall fell, with several thousands or up to 10,000 individuals estimated to have become victims, 5,000 of whom sustained irreversible damage. Special pensions for restitution have been created for Zersetzung victims.

🔗 Mathematics

In geometry, a 65537-gon is a polygon with 65,537 (2¹⁶ + 1) sides. The sum of the interior angles of any non–self-intersecting 65537-gon is 11796300°.

🔗 Systems

Chartjunk consists of all visual elements in charts and graphs that are not necessary to comprehend the information represented on the graph, or that distract the viewer from this information.

Markings and visual elements can be called chartjunk if they are not part of the minimum set of visuals necessary to communicate the information understandably. Examples of unnecessary elements that might be called chartjunk include heavy or dark grid lines, unnecessary text, inappropriately complex or gimmicky font faces, ornamented chart axes, and display frames, pictures, backgrounds or icons within data graphs, ornamental shading and unnecessary dimensions.

Another kind of chartjunk skews the depiction and makes it difficult to understand the real data being displayed. Examples of this type include items depicted out of scale to one another, noisy backgrounds making comparison between elements difficult in a chart or graph, and 3-D simulations in line and bar charts.

The term chartjunk was coined by Edward Tufte in his 1983 book The Visual Display of Quantitative Information. Tufte wrote:

The interior decoration of graphics generates a lot of ink that does not tell the viewer anything new. The purpose of decoration varies—to make the graphic appear more scientific and precise, to enliven the display, to give the designer an opportunity to exercise artistic skills. Regardless of its cause, it is all non-data-ink or redundant data-ink, and it is often chartjunk.

The term is relatively recent and is often associated with Tufte in other references.

The concept is analogous to Adolf Loos's idea that ornament is a crime.

🔗 Ecology

The Lotka–Volterra equations, also known as the Lotka–Volterra predator–prey model, are a pair of first-order nonlinear differential equations, frequently used to describe the dynamics of biological systems in which two species interact, one as a predator and the other as prey. The populations change through time according to the pair of equations: $${\displaystyle {\begin{aligned}{\frac {dx}{dt}}&=\alpha x-\beta xy,\\{\frac {dy}{dt}}&=-\gamma y+\delta xy,\end{aligned}}}$$

where

• the variable x is the population density of prey (for example, the number of rabbits per square kilometre);
• the variable y is the population density of some predator (for example, the number of foxes per square kilometre);
• ${\displaystyle {\tfrac {dy}{dt}}}$ and ${\displaystyle {\tfrac {dx}{dt}}}$ represent the instantaneous growth rates of the two populations;
• t represents time;
• The prey's parameters, α and β, describe, respectively, the maximum prey per capita growth rate, and the effect of the presence of predators on the prey death rate.
• The predator's parameters, γ, δ, respectively describe the predator's per capita death rate, and the effect of the presence of prey on the predator's growth rate.
• All parameters are positive and real.

The solution of the differential equations is deterministic and continuous. This, in turn, implies that the generations of both the predator and prey are continually overlapping.

The Lotka–Volterra system of equations is an example of a Kolmogorov population model (not to be confused with the better known Kolmogorov equations), which is a more general framework that can model the dynamics of ecological systems with predator–prey interactions, competition, disease, and mutualism.