Have a deep view into what people are curious about.

🔗 Biography 🔗 Mathematics 🔗 Environment 🔗 Iran 🔗 Biography/science and academia 🔗 Astronomy 🔗 Geography 🔗 History of Science 🔗 Astrology 🔗 Middle Ages 🔗 Islam 🔗 Middle Ages/History 🔗 Central Asia 🔗 Maps 🔗 Iraq 🔗 Biography/Core biographies 🔗 Islam/Muslim scholars

Muḥammad ibn Mūsā al-Khwārizmī (Persian: Muḥammad Khwārizmī محمد بن موسی خوارزمی‎; c. 780 – c. 850), Arabized as al-Khwarizmi with al- and formerly Latinized as Algorithmi, was a Persian polymath who produced works in mathematics, astronomy, and geography. Around 820 CE he was appointed as the astronomer and head of the library of the House of Wisdom in Baghdad.

Al-Khwarizmi's popularizing treatise on algebra (The Compendious Book on Calculation by Completion and Balancing, c. 813–833 CE) presented the first systematic solution of linear and quadratic equations. One of his principal achievements in algebra was his demonstration of how to solve quadratic equations by completing the square, for which he provided geometric justifications. Because he was the first to treat algebra as an independent discipline and introduced the methods of "reduction" and "balancing" (the transposition of subtracted terms to the other side of an equation, that is, the cancellation of like terms on opposite sides of the equation), he has been described as the father or founder of algebra. The term algebra itself comes from the title of his book (specifically the word al-jabr meaning "completion" or "rejoining"). His name gave rise to the terms algorism and algorithm. His name is also the origin of (Spanish) guarismo and of (Portuguese) algarismo, both meaning digit.

In the 12th century, Latin translations of his textbook on arithmetic (Algorithmo de Numero Indorum) which codified the various Indian numerals, introduced the decimal positional number system to the Western world. The Compendious Book on Calculation by Completion and Balancing, translated into Latin by Robert of Chester in 1145, was used until the sixteenth century as the principal mathematical text-book of European universities.

In addition to his best-known works, he revised Ptolemy's Geography, listing the longitudes and latitudes of various cities and localities. He further produced a set of astronomical tables and wrote about calendaric works, as well as the astrolabe and the sundial. He also made important contributions to trigonometry, producing accurate sine and cosine tables, and the first table of tangents.

🔗 Economics

The term exorbitant privilege (privilège exorbitant in French) refers to the benefits the United States has due to its own currency (the US dollar) being the international reserve currency. For example, the US would not face a balance of payments crisis, because their imports are purchased in their own currency. Exorbitant privilege as a concept cannot refer to currencies that have a regional reserve currency role, only to global reserve currencies.

Academically, the exorbitant privilege literature analyzes two empirical puzzles, the position puzzle and the income puzzle. The position puzzle refers to the difference between the (negative) U.S. net international investment position (NIIP) and the accumulated U.S. current account deficits, the former being much smaller than the latter. The income puzzle is that despite a deeply negative NIIP, the U.S. income balance is positive, i.e. despite having much more liabilities than assets, earned income is higher than interest expenses.

🔗 Computer science

In computer architecture, Amdahl's law (or Amdahl's argument) is a formula which gives the theoretical speedup in latency of the execution of a task at fixed workload that can be expected of a system whose resources are improved. It is named after computer scientist Gene Amdahl, and was presented at the AFIPS Spring Joint Computer Conference in 1967.

Amdahl's law is often used in parallel computing to predict the theoretical speedup when using multiple processors. For example, if a program needs 20 hours to complete using a single thread, but a one-hour portion of the program cannot be parallelized, therefore only the remaining 19 hours (p = 0.95) of execution time can be parallelized, then regardless of how many threads are devoted to a parallelized execution of this program, the minimum execution time cannot be less than one hour. Hence, the theoretical speedup is limited to at most 20 times the single thread performance, ${\displaystyle \left({\dfrac {1}{1-p}}=20\right)}$.

🔗 Mathematics 🔗 Geography

The haversine formula determines the great-circle distance between two points on a sphere given their longitudes and latitudes. Important in navigation, it is a special case of a more general formula in spherical trigonometry, the law of haversines, that relates the sides and angles of spherical triangles.

The first table of haversines in English was published by James Andrew in 1805, but Florian Cajori credits an earlier use by José de Mendoza y Ríos in 1801. The term haversine was coined in 1835 by James Inman.

These names follow from the fact that they are customarily written in terms of the haversine function, given by hav(θ) = sin²(θ/2). The formulas could equally be written in terms of any multiple of the haversine, such as the older versine function (twice the haversine). Prior to the advent of computers, the elimination of division and multiplication by factors of two proved convenient enough that tables of haversine values and logarithms were included in nineteenth and early twentieth century navigation and trigonometric texts. These days, the haversine form is also convenient in that it has no coefficient in front of the sin² function.

Vital articles are lists of subjects for which the English Wikipedia should have corresponding featured-class articles. They serve as centralized watchlists to track the status of Wikipedia's most important articles. The very most important articles are in Level 1.

This page constitutes Level 3 of the vital articles list and includes approximately 1,000 articles. All articles from higher levels are also included in lower levels. For example, all 100 subjects on the Level 2 list (shown on this page in bold font) are included here in Level 3. And the Level 2 list also includes the 10 subjects on Level 1 (shown on this page in bold italics). A larger Level 4 list of 10,000 articles also exists, and a Level 5 list of 50,000 articles is in the process of being created.

Articles are labelled as:

These symbols and article counts are updated daily by User:cewbot.

• The bot only update counter with the pattern "(000 articles)" in section title.
• All attributes of articles get from corresponding categories.
• The bot will automatically update the summary table if there are summary table marks.

This list is tailored to the English-language Wikipedia. There is also a list of one thousand articles considered vital to Wikipedias of all languages, as well as Vital Article lists tailored to different Wikipedia languages accessible via the languages sidebar.

Articles should not be added or removed from this list without a consensus on the talk page. For more information on this list and the process for adding or removing articles, please see the Frequently Asked Questions (FAQ) page.

🔗 Computing 🔗 Philosophy

The principle of least astonishment (POLA), also called the principle of least surprise (alternatively a "law" or "rule") applies to user interface and software design. A typical formulation of the principle, from 1984, is: "If a necessary feature has a high astonishment factor, it may be necessary to redesign the feature."

More generally, the principle means that a component of a system should behave in a way that most users will expect it to behave; the behavior should not astonish or surprise users.

🔗 Finance & Investment 🔗 China 🔗 Economics

Zhima Credit (Chinese: 芝麻信用; pinyin: Zhīma Xìnyòng), also known as Sesame Credit, is a private credit scoring and loyalty program system developed by Ant Financial Services Group (AFSG), an affiliate of the Chinese Alibaba Group. It uses data from Alibaba's services to compile its score. Customers receive a score based on a variety of factors based on social media interactions and purchases carried out on Alibaba Group websites or paid for using its affiliate Ant Financial's Alipay mobile wallet. The rewards of having a high score include easier access to loans from Ant Financial and having a more trustworthy profile on e-commerce sites within the Alibaba Group.

🔗 Philosophy 🔗 Philosophy/Logic 🔗 Business 🔗 Philosophy/Philosophy of science 🔗 Science

Wronger than wrong is a statement that equates two errors when one of the errors is clearly more wrong than the other. It was described by Michael Shermer as Asimov's axiom. The mistake was discussed in Isaac Asimov's book of essays The Relativity of Wrong as well as in a 1989 article of the same name in the Fall 1989 issue of the Skeptical Inquirer:

When people thought the Earth was flat, they were wrong. When people thought the Earth was spherical, they were wrong. But if you think that thinking the Earth is spherical is just as wrong as thinking the Earth is flat, then your view is wronger than both of them put together.

Asimov explained that science is both progressive and cumulative. Even though scientific theories are later proven wrong, the degree of their wrongness attenuates with time as they are modified in response to the mistakes of the past. For example, data collected from satellite measurements show, to a high level of precision, how the Earth's shape differs from a perfect sphere or even an oblate spheroid or a geoid.

Shermer stated that being wronger than wrong is actually worse than being not even wrong (that is, being unfalsifiable).

According to John Jenkins, who reviewed The Relativity of Wrong, the title essay of Asimov's book is the one "which I think is important both for understanding Asimov's thinking about science and for arming oneself against the inevitable anti-science attack that one often hears – [that] theories are always preliminary and science really doesn't 'know' anything."

🔗 Russia 🔗 Russia/technology and engineering in Russia 🔗 Spaceflight 🔗 Europe 🔗 China 🔗 Russia/science and education in Russia 🔗 Europe/ESA 🔗 Solar System/Mars 🔗 Solar System

The Mars-500 mission was a psychosocial isolation experiment conducted between 2007 and 2011 by Russia, the European Space Agency and China, in preparation for an unspecified future crewed spaceflight to the planet Mars. The experiment's facility was located at the Russian Academy of Sciences' Institute of Biomedical Problems (IBMP) in Moscow, Russia.

Between 2007 and 2011, three different crews of volunteers lived and worked in a mock-up spacecraft at IBMP. The final stage of the experiment, which was intended to simulate a 520-day crewed mission, was conducted by an all-male crew consisting of three Russians (Alexey Sitev, Sukhrob Kamolov, Alexander Smoleevskij), a Frenchman (Romain Charles), an Italian (Diego Urbina) and a Chinese citizen (Yue Wang). The mock-up facility simulated an Earth-Mars shuttle spacecraft, an ascent-descent craft, and the Martian surface. The volunteers who participated in the three stages included professionals with experience in engineering, medicine, biology, and human spaceflight. The experiment yielded important data on the physiological, social and psychological effects of long-term close-quarters isolation.

🔗 Economics

The parable of the broken window was introduced by French economist Frédéric Bastiat in his 1850 essay "That Which We See and That Which We Do Not See" ("Ce qu'on voit et ce qu'on ne voit pas") to illustrate why destruction, and the money spent to recover from destruction, is not actually a net benefit to society.

The parable seeks to show how opportunity costs, as well as the law of unintended consequences, affect economic activity in ways that are unseen or ignored. The belief that destruction is good for the economy is consequently known as the broken window fallacy or glazier's fallacy.