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🔗 Computing 🔗 Books 🔗 Computing/Software

The Cathedral and the Bazaar: Musings on Linux and Open Source by an Accidental Revolutionary (abbreviated CatB) is an essay, and later a book, by Eric S. Raymond on software engineering methods, based on his observations of the Linux kernel development process and his experiences managing an open source project, fetchmail. It examines the struggle between top-down and bottom-up design. The essay was first presented by the author at the Linux Kongress on May 27, 1997 in Würzburg (Germany) and was published as part of the book in 1999.

The illustration on the cover of the book is a 1913 painting by Liubov Popova titled Composition with Figures and belongs to the collection of the State Tretyakov Gallery. The book was released under the Open Publication License v2.0 around 1999.

🔗 Computing 🔗 Computing/Computer hardware

N8VEM was a homebrew computing project. It featured a variety of free and open hardware and software. N8VEM builders made their own homebrew computer systems for themselves and shared their experiences with other homebrew computer hobbyists. N8VEM homebrew computer components are made in the style of vintage computers of the mid to late 1970s and early 1980s using a mix of classic and modern technologies. They are designed with ease of amateur assembly in mind.

In November 2015 the N8VEM project was ended by its creator Andrew Lynch and the community reconvened under the new name of Retrobrew Computers.

🔗 Computing 🔗 Computing/Computer science

m4 is a general-purpose macro processor included in all UNIX-like operating systems, and is a component of the POSIX standard.

The language was designed by Brian Kernighan and Dennis Ritchie for the original versions of UNIX. It is an extension of an earlier macro processor m3, written by Ritchie for an unknown AP-3 minicomputer.

The macro preprocessor operates as a text-replacement tool. It is employed to re-use text templates, typically in computer programming applications, but also in text editing and text-processing applications. Most users require m4 as a dependency of GNU autoconf.

🔗 Polynesia 🔗 Organizations 🔗 Hawaii

The Polynesian Voyaging Society (PVS) is a non-profit research and educational corporation based in Honolulu, Hawaiʻi. PVS was established to research and perpetuate traditional Polynesian voyaging methods. Using replicas of traditional double-hulled canoes, PVS undertakes voyages throughout Polynesia navigating without modern instruments.

🔗 Books 🔗 England 🔗 Middle Ages 🔗 Middle Ages/History 🔗 Food and drink

The Forme of Cury (The Method of Cooking, cury from Middle French cuire: 'to cook') is an extensive 14th-century collection of medieval English recipes. Although the original manuscript is lost, the text appears in nine manuscripts, the most famous in the form of a scroll with a headnote citing it as the work of "the chief Master Cooks of King Richard II". The name The Forme of Cury is generally used for the family of recipes rather than any single manuscript text. It is among the oldest extant English cookery books, and the earliest known to mention olive oil, gourds, and spices such as mace and cloves.

🔗 History 🔗 Military history 🔗 British Empire 🔗 Military history/World War I 🔗 Politics of the United Kingdom 🔗 Arab world 🔗 Jewish history 🔗 Israel 🔗 Palestine 🔗 Former countries 🔗 Military history/Middle Eastern military history 🔗 Former countries/Ottoman Empire 🔗 British Library

The Balfour Declaration was a public statement issued by the British government in 1917 during the First World War announcing its support for the establishment of a "national home for the Jewish people" in Palestine, then an Ottoman region with a small minority Jewish population. The declaration was contained in a letter dated 2 November 1917 from the United Kingdom's Foreign Secretary Arthur Balfour to Lord Rothschild, a leader of the British Jewish community, for transmission to the Zionist Federation of Great Britain and Ireland. The text of the declaration was published in the press on 9 November 1917.

Immediately following their declaration of war on the Ottoman Empire in November 1914, the British War Cabinet began to consider the future of Palestine; within two months a memorandum was circulated to the Cabinet by a Zionist Cabinet member, Herbert Samuel, proposing the support of Zionist ambitions in order to enlist the support of Jews in the wider war. A committee was established in April 1915 by British Prime Minister H. H. Asquith to determine their policy towards the Ottoman Empire including Palestine. Asquith, who had favoured post-war reform of the Ottoman Empire, resigned in December 1916; his replacement David Lloyd George favoured partition of the Empire. The first negotiations between the British and the Zionists took place at a conference on 7 February 1917 that included Sir Mark Sykes and the Zionist leadership. Subsequent discussions led to Balfour's request, on 19 June, that Rothschild and Chaim Weizmann submit a draft of a public declaration. Further drafts were discussed by the British Cabinet during September and October, with input from Zionist and anti-Zionist Jews but with no representation from the local population in Palestine.

By late 1917, in the lead-up to the Balfour Declaration, the wider war had reached a stalemate, with two of Britain's allies not fully engaged: the United States had yet to suffer a casualty, and the Russians were in the midst of a revolution with Bolsheviks taking over the government. A stalemate in southern Palestine was broken by the Battle of Beersheba on 31 October 1917. The release of the final declaration was authorised on 31 October; the preceding Cabinet discussion had referenced perceived propaganda benefits amongst the worldwide Jewish community for the Allied war effort.

The opening words of the declaration represented the first public expression of support for Zionism by a major political power. The term "national home" had no precedent in international law, and was intentionally vague as to whether a Jewish state was contemplated. The intended boundaries of Palestine were not specified, and the British government later confirmed that the words "in Palestine" meant that the Jewish national home was not intended to cover all of Palestine. The second half of the declaration was added to satisfy opponents of the policy, who had claimed that it would otherwise prejudice the position of the local population of Palestine and encourage antisemitism worldwide by "stamping the Jews as strangers in their native lands". The declaration called for safeguarding the civil and religious rights for the Palestinian Arabs, who composed the vast majority of the local population, and also the rights and political status of the Jewish communities in other countries outside of Palestine. The British government acknowledged in 1939 that the local population's wishes and interests should have been taken into account, and recognised in 2017 that the declaration should have called for the protection of the Palestinian Arabs' political rights.

The declaration had many long-lasting consequences. It greatly increased popular support for Zionism within Jewish communities worldwide, and became a core component of the British Mandate for Palestine, the founding document of Mandatory Palestine. It indirectly led to the emergence of Israel and is considered a principal cause of the ongoing Israeli–Palestinian conflict, often described as the world's most intractable conflict. Controversy remains over a number of areas, such as whether the declaration contradicted earlier promises the British made to the Sharif of Mecca in the McMahon–Hussein correspondence.

🔗 Psychology

The McCollough effect is a phenomenon of human visual perception in which colorless gratings appear colored contingent on the orientation of the gratings. It is an aftereffect requiring a period of induction to produce it. For example, if someone alternately looks at a red horizontal grating and a green vertical grating for a few minutes, a black-and-white horizontal grating will then look greenish and a black-and-white vertical grating will then look pinkish. The effect is remarkable because, where time-elapse testing is employed, it has been reported to last up to 2.8 months.

The effect was discovered by American psychologist Celeste McCollough in 1965.

🔗 Computing 🔗 Michigan

The Michigan Terminal System (MTS) is one of the first time-sharing computer operating systems. Developed in 1967 at the University of Michigan for use on IBM S/360-67, S/370 and compatible mainframe computers, it was developed and used by a consortium of eight universities in the United States, Canada, and the United Kingdom over a period of 33 years (1967 to 1999).

🔗 Climate change 🔗 Environment 🔗 Meteorology 🔗 Urban studies and planning

An urban heat island (UHI) is an urban area or metropolitan area that is significantly warmer than its surrounding rural areas due to human activities. The temperature difference is usually larger at night than during the day, and is most apparent when winds are weak. UHI is most noticeable during the summer and winter. The main cause of the urban heat island effect is from the modification of land surfaces. Waste heat generated by energy usage is a secondary contributor. As a population center grows, it tends to expand its area and increase its average temperature. The term heat island is also used; the term can be used to refer to any area that is relatively hotter than the surrounding, but generally refers to human-disturbed areas.

Monthly rainfall is greater downwind of cities, partially due to the UHI. Increases in heat within urban centers increases the length of growing seasons, and decreases the occurrence of weak tornadoes. The UHI decreases air quality by increasing the production of pollutants such as ozone, and decreases water quality as warmer waters flow into area streams and put stress on their ecosystems.

Not all cities have a distinct urban heat island, and the heat island characteristics depend strongly on the background climate of the area in which the city is located. Mitigation of the urban heat island effect can be accomplished through the use of green roofs and the use of lighter-colored surfaces in urban areas, which reflect more sunlight and absorb less heat.

Concerns have been raised about possible contribution from urban heat islands to global warming. While some lines of research did not detect a significant impact, other studies have concluded that heat islands can have measurable effects on climate phenomena at the global scale.

🔗 Electronics

In signal processing, the Nyquist frequency (or folding frequency), named after Harry Nyquist, is a characteristic of a sampler, which converts a continuous function or signal into a discrete sequence. For a given sampling rate (samples per second), the Nyquist frequency (cycles per second) is the frequency whose cycle-length (or period) is twice the interval between samples, thus 0.5 cycle/sample. For example, audio CDs have a sampling rate of 44100 samples/second. At 0.5 cycle/sample, the corresponding Nyquist frequency is 22050 cycles/second (Hz). Conversely, the Nyquist rate for sampling a 22050 Hz signal is 44100 samples/second.

When the highest frequency (bandwidth) of a signal is less than the Nyquist frequency of the sampler, the resulting discrete-time sequence is said to be free of the distortion known as aliasing, and the corresponding sample rate is said to be above the Nyquist rate for that particular signal.

In a typical application of sampling, one first chooses the highest frequency to be preserved and recreated, based on the expected content (voice, music, etc.) and desired fidelity. Then one inserts an anti-aliasing filter ahead of the sampler. Its job is to attenuate the frequencies above that limit. Finally, based on the characteristics of the filter, one chooses a sample rate (and corresponding Nyquist frequency) that will provide an acceptably small amount of aliasing. In applications where the sample rate is pre-determined (such as the CD rate), the filter is chosen based on the Nyquist frequency, rather than vice versa.