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🔗 United States 🔗 Military history 🔗 Disaster management 🔗 Military history/North American military history 🔗 Military history/United States military history 🔗 Terrorism 🔗 New York City 🔗 Military history/World War I 🔗 New Jersey 🔗 Public Art 🔗 New Jersey/Hudson County

The Black Tom explosion was an act of sabotage by German agents to destroy U.S.-made munitions that were to be supplied to the Allies in World War I. The explosions, which occurred on July 30, 1916, in the New York Harbor, killed four people and destroyed some $20,000,000 worth of military goods. This incident, which happened prior to U.S. entry into World War I, also damaged the Statue of Liberty. It was one of the largest artificial non-nuclear explosions to have ever occurred.

🔗 Technology 🔗 Computing 🔗 Mathematics

A slide rule is a hand-operated mechanical calculator consisting of slidable rulers for evaluating mathematical operations such as multiplication, division, exponents, roots, logarithms, and trigonometry. It is one of the simplest analog computers.

Slide rules exist in a diverse range of styles and generally appear in a linear, circular or cylindrical form. Slide rules manufactured for specialized fields such as aviation or finance typically feature additional scales that aid in specialized calculations particular to those fields. The slide rule is closely related to nomograms used for application-specific computations. Though similar in name and appearance to a standard ruler, the slide rule is not meant to be used for measuring length or drawing straight lines. Nor is it designed for addition or subtraction, which is usually performed using other methods, like using an abacus. Maximum accuracy for standard linear slide rules is about three decimal significant digits, while scientific notation is used to keep track of the order of magnitude of results.

English mathematician and clergyman Reverend William Oughtred and others developed the slide rule in the 17th century based on the emerging work on logarithms by John Napier. It made calculations faster and less error-prone than evaluating on paper. Before the advent of the scientific pocket calculator, it was the most commonly used calculation tool in science and engineering. The slide rule's ease of use, ready availability, and low cost caused its use to continue to grow through the 1950s and 1960s, even as desktop electronic computers were gradually introduced. But after the handheld scientific calculator was introduced in 1972 and became inexpensive in the mid-1970s, slide rules became largely obsolete, so most suppliers departed the business.

In the United States, the slide rule is colloquially called a slipstick.

🔗 Internet 🔗 China

50 Cent Party, 50 Cent Army and wumao ( WOO-mow) are terms for Internet commentators who are hired by the authorities of the People's Republic of China to manipulate public opinion and disseminate disinformation to the benefit of the governing Chinese Communist Party (CCP). It was created during the early phases of the Internet's rollout to the wider public in China.

The name is derived from the allegation that such commentators are paid RMB¥0.50 for every post. These commentators create comments or articles on popular Chinese social media networks that are intended to derail discussions which are critical of the CCP, promoting narratives that serve the government's interests and insulting or spreading misinformation about political opponents of the Chinese government, both domestic and abroad. Some of these commentators have labeled themselves ziganwu (Chinese: 自干五, short for 自带干粮的五毛, lit. 'wumao who bring their own dry rations'), claiming they are not paid by authorities and express their support for the Chinese government out of their own volition.

Authors of a paper published in 2017 in the American Political Science Review estimate that the Chinese government fabricates 488 million social media posts per year. In contrast to common assumptions, the 50 Cent Party consists mostly of paid bureaucrats who respond to government directives and rarely defend their government from criticism or engage in direct arguments because "... the goal of this massive secretive operation is instead to distract the public and change the subject." Around 80% of the analysed posts involve pro-China cheerleading with inspirational slogans, and 13% involve general praise and suggestions on governmental policies. Despite the common allegation of the commentators getting paid for their posts, the paper suggested there was "no evidence" that they are paid anything for their posts, instead being required to do so as a part of their official party duties.

Research by professors at Harvard, Stanford, and UC San Diego indicated a "massive secretive operation" to fill China's Internet with propaganda, and has resulted in some 488 million posts written by fake social media accounts, representing about 0.6% of the 80 billion posts generated on Chinese social media. To maximize their influence, such pro-government comments are made largely during times of intense online debate, and when online protests have a possibility of transforming into real life actions. The colloquial term wumao has also been used by some English speakers outside of China as an insult against people with perceived pro-CCP bias.

🔗 United States 🔗 Computing 🔗 Television 🔗 United States/American television

Halt and Catch Fire is an American period drama television series created by Christopher Cantwell and Christopher C. Rogers. It aired on the cable network AMC in the United States from June 1, 2014, to October 14, 2017, spanning four seasons and 40 episodes. Taking place over a period of more than ten years, the series depicts a fictionalized insider's view of the personal computer revolution of the 1980s and the growth of the World Wide Web in the early 1990s. The show's title refers to computer machine code instruction Halt and Catch Fire (HCF), the execution of which would cause the computer's central processing unit to stop working (catch fire being a humorous exaggeration).

In season one, the company Cardiff Electric makes its first foray into personal computing, with entrepreneur Joe MacMillan (Lee Pace) running a project to build an IBM PC clone with the help of computer engineer Gordon Clark (Scoot McNairy) and prodigy programmer Cameron Howe (Mackenzie Davis). Seasons two and three shift focus to a startup company, the online community Mutiny, that is headed by Cameron and Gordon's wife Donna (Kerry Bishé), while Joe ventures out on his own. The fourth and final season focuses on competing web search engines involving all the principal characters.

Halt and Catch Fire marked Cantwell's and Rogers's first jobs in television. They wrote the pilot hoping to use it to secure jobs as writers in the industry but instead landed a series of their own from AMC. The story was inspired by Cantwell's childhood in the Silicon Prairie of Dallas–Fort Worth, where his father worked as a software salesman, and the creators' subsequent research into Texas's role in personal computing innovations of the 1980s. Filmed in the Atlanta, Georgia, area and produced by the network, the series is set in the Silicon Prairie for its first two seasons and Silicon Valley for its latter two.

Halt and Catch Fire debuted to generally favorable reviews, though many reviewers initially found it derivative of other series such as Mad Men. In each subsequent season, the series grew in acclaim, and by the time it concluded, critics considered it among the best shows of the 2010s. Despite its critical reception, the series experienced low viewership ratings throughout its run, with only the first episode surpassing one million viewers for its initial broadcast.

🔗 Internet 🔗 Media 🔗 Cuba

El Paquete Semanal ("The Weekly Package") or El Paquete is a one terabyte collection of digital material distributed since around 2008 on the underground market in Cuba as a substitute for broadband Internet. Since 2015, it has been the primary source of entertainment for millions of Cubans, as Internet in Cuba has been suppressed for many years with only about a 38.8% Internet penetration rate as of 2018. El Paquete Semanal has its own page that is running in the United States, where one could view its contents and is consistently updated every week.

🔗 Science 🔗 Tree of Life

Lumpers and splitters are opposing factions in any discipline that has to place individual examples into rigorously defined categories. The lumper–splitter problem occurs when there is the desire to create classifications and assign examples to them, for example schools of literature, biological taxa and so on. A "lumper" is an individual who takes a gestalt view of a definition, and assigns examples broadly, assuming that differences are not as important as signature similarities. A "splitter" is an individual who takes precise definitions, and creates new categories to classify samples that differ in key ways.

🔗 Astronomy 🔗 Maps

HEALPix (sometimes written as Healpix), an acronym for Hierarchical Equal Area isoLatitude Pixelisation of a 2-sphere, is an algorithm for pixelisation of the 2-sphere and the associated class of map projections. The pixelisation algorithm was devised in 1997 by Krzysztof M. Górski at the Theoretical Astrophysics Center in Copenhagen, Denmark, and first published as a preprint in 1998.

🔗 Physics

The Foucault pendulum or Foucault's pendulum is a simple device named after French physicist Léon Foucault and conceived as an experiment to demonstrate the Earth's rotation. The pendulum was introduced in 1851 and was the first experiment to give simple, direct evidence of the earth's rotation. Foucault pendulums today are popular displays in science museums and universities.

🔗 New York City 🔗 Engineering

The Citicorp Center engineering crisis was the discovery, in 1978, of a significant structural flaw in Citicorp Center, then a recently completed skyscraper in New York City, and the subsequent effort to quietly make repairs over the next few months. The building, now known as Citigroup Center, occupied an entire block and was to be the headquarters of Citibank. Its structure, designed by William LeMessurier, had several unusual design features, including a raised base supported by four offset stilts, and diagonal bracing which absorbed wind loads from upper stories.

In the original design, potential wind loads for the building were calculated incorrectly. The flaw was discovered by Diane Hartley, an undergraduate student at Princeton University who was writing a thesis on the building, and was communicated to the firm responsible for the structural design. LeMessurier was subsequently lauded for acknowledging his error and orchestrating a successful repair effort. Estimates at the time suggested that the building could be toppled by a 70-mile-per-hour (110 km/h) wind, with possibly many people killed as a result. The crisis was kept secret until 1995 and Hartley had no knowledge of the significance of her work until after that time.

🔗 Philosophy 🔗 Systems 🔗 Philosophy/Social and political philosophy 🔗 Sociology 🔗 Philosophy/Ethics 🔗 Philosophy/Metaphysics

In the social sciences, unintended consequences (sometimes unanticipated consequences or unforeseen consequences) are outcomes of a purposeful action that are not intended or foreseen. The term was popularised in the twentieth century by American sociologist Robert K. Merton.

Unintended consequences can be grouped into three types:

• Unexpected benefit: A positive unexpected benefit (also referred to as luck, serendipity or a windfall).
• Unexpected drawback: An unexpected detriment occurring in addition to the desired effect of the policy (e.g., while irrigation schemes provide people with water for agriculture, they can increase waterborne diseases that have devastating health effects, such as schistosomiasis).
• Perverse result: A perverse effect contrary to what was originally intended (when an intended solution makes a problem worse).