Have a deep view into what people are curious about.

Lehmer sieves are mechanical devices that implement sieves in number theory. Lehmer sieves are named for Derrick Norman Lehmer and his son Derrick Henry Lehmer. The father was a professor of mathematics at the University of California, Berkeley at the time, and his son followed in his footsteps as a number theorist and professor at Berkeley.

A sieve in general is intended to find the numbers which are remainders when a set of numbers are divided by a second set. Generally, they are used in finding solutions of Diophantine equations or to factor numbers. A Lehmer sieve will signal that such solutions are found in a variety of ways depending on the particular construction.

PechaKucha (Japanese: ぺちゃくちゃ, IPA: [petɕa kɯ̥tɕa], chit-chat) is a storytelling format where a presenter shows 20 slides for 20 seconds of commentary each (6 minutes and 40 seconds total). At a PechaKucha Night, individuals gather at a venue to share personal presentations about their work. The PechaKucha format can be used, for example, in business presentations to clients or staff, as well as in education settings.

Inspired by their desire to "talk less, show more," Astrid Klein and Mark Dytham of Tokyo's Klein-Dytham Architecture (KDa) created PechaKucha in February 2003. It was a way to attract people to SuperDeluxe, their experimental event space in Roppongi, and to enable young designers to meet, show their work, and exchange ideas in 6 minutes 40 seconds.

In 2004, cities in Europe began hosting PK Nights and days, followed over the years by hundreds of others. As of April 2019, PKNs had been held in more than 1,142 cities worldwide. More than 3 million people have attended a PK Night.

PechaKucha is a registered trademark of PechaKucha, Inc.

In January 2018, PK's Astrid Klein, Mark Dytham, and Sean Smyth established PK, Inc. to create software to expand the PK platform.

The year 1816 is known as the Year Without a Summer (also the Poverty Year and Eighteen Hundred and Froze To Death) because of severe climate abnormalities that caused average global temperatures to decrease by 0.4–0.7 °C (0.72–1.26 °F). This resulted in major food shortages across the Northern Hemisphere.

Evidence suggests that the anomaly was predominantly a volcanic winter event caused by the massive 1815 eruption of Mount Tambora in April in the Dutch East Indies (now Indonesia). This eruption was the largest eruption in at least 1,300 years (after the hypothesized eruption causing the extreme weather events of 535–536), and perhaps exacerbated by the 1814 eruption of Mayon in the Philippines.

Hashlife is a memoized algorithm for computing the long-term fate of a given starting configuration in Conway's Game of Life and related cellular automata, much more quickly than would be possible using alternative algorithms that simulate each time step of each cell of the automaton. The algorithm was first described by Bill Gosper in the early 1980s while he was engaged in research at the Xerox Palo Alto Research Center. Hashlife was originally implemented on Symbolics Lisp machines with the aid of the Flavors extension.

"The Analytical Language of John Wilkins" (Spanish: "El idioma analítico de John Wilkins") is a short essay by Argentine writer Jorge Luis Borges, first printed in La Nación on 8 February 1942 and subsequently published in Otras Inquisiciones (1937–1952). It is a critique of the English natural philosopher and writer John Wilkins's proposal for a universal language and of the representational capacity of language generally. In it, Borges imagines a bizarre and whimsical (and fictional) Chinese taxonomy later quoted by Michel Foucault, David Byrne, and others.

The Cyrix 6x86 is a line of sixth-generation, 32-bit x86 microprocessors designed and released by Cyrix in 1995. Cyrix, being a fabless company, had the chips manufactured by IBM and SGS-Thomson. The 6x86 was made as a direct competitor to Intel's Pentium microprocessor line, and was pin compatible. During the 6x86's development, the majority of applications (office software as well as games) performed almost entirely integer operations. The designers foresaw that future applications would most likely maintain this instruction focus. So, to optimize the chip's performance for what they believed to be the most likely application of the CPU, the integer execution resources received most of the transistor budget. This would later prove to be a strategic mistake, as the popularity of the P5 Pentium caused many software developers to hand-optimize code in assembly language, to take advantage of the P5 Pentium's tightly pipelined and lower latency FPU. For example, the highly anticipated first-person shooter Quake used highly optimized assembly code designed almost entirely around the P5 Pentium's FPU. As a result, the P5 Pentium significantly outperformed other CPUs in the game.

In social choice theory, Arrow's impossibility theorem, the general possibility theorem or Arrow's paradox is an impossibility theorem stating that when voters have three or more distinct alternatives (options), no ranked voting electoral system can convert the ranked preferences of individuals into a community-wide (complete and transitive) ranking while also meeting a specified set of criteria: unrestricted domain, non-dictatorship, Pareto efficiency, and independence of irrelevant alternatives. The theorem is often cited in discussions of voting theory as it is further interpreted by the Gibbard–Satterthwaite theorem. The theorem is named after economist and Nobel laureate Kenneth Arrow, who demonstrated the theorem in his doctoral thesis and popularized it in his 1951 book Social Choice and Individual Values. The original paper was titled "A Difficulty in the Concept of Social Welfare".

In short, the theorem states that no rank-order electoral system can be designed that always satisfies these three "fairness" criteria:

• If every voter prefers alternative X over alternative Y, then the group prefers X over Y.
• If every voter's preference between X and Y remains unchanged, then the group's preference between X and Y will also remain unchanged (even if voters' preferences between other pairs like X and Z, Y and Z, or Z and W change).
• There is no "dictator": no single voter possesses the power to always determine the group's preference.

Cardinal voting electoral systems are not covered by the theorem, as they convey more information than rank orders. However, Gibbard's theorem extends Arrow's theorem for that case. The theorem can also be sidestepped by weakening the notion of independence.

The axiomatic approach Arrow adopted can treat all conceivable rules (that are based on preferences) within one unified framework. In that sense, the approach is qualitatively different from the earlier one in voting theory, in which rules were investigated one by one. One can therefore say that the contemporary paradigm of social choice theory started from this theorem.

The practical consequences of the theorem are debatable: Arrow has said "Most systems are not going to work badly all of the time. All I proved is that all can work badly at times."

Yuan Longping (Chinese: 袁隆平; September 7, 1930 – May 22, 2021) was a Chinese agronomist, member of the Chinese Academy of Engineering, known for developing the first hybrid rice varieties in the 1970s.

Hybrid rice has since been grown in dozens of countries in Africa, America, and Asia—providing a robust food source in areas with a high risk of famine. For his contributions, Yuan is always called the "Father of Hybrid Rice" by the Chinese media. On May 22, 2021, Yuan Longping died of multiple organ failure at the age of 90.

THX 1138 is a 1971 American social science fiction film directed by George Lucas in his feature film directorial debut. It is set in a dystopian future in which the populace is controlled through android police and mandatory use of drugs that suppress emotions. Produced by Francis Ford Coppola and written by Lucas and Walter Murch, it stars Robert Duvall and Donald Pleasence.

THX 1138 was developed from Lucas's student film Electronic Labyrinth: THX 1138 4EB, which he made in 1967 while attending the USC School of Cinematic Arts. The feature film was produced in a joint venture between Warner Bros. and American Zoetrope. A novelization by Ben Bova was published in 1971. The film received mixed reviews from critics and failed to find box-office success on initial release; however, the film has subsequently received critical acclaim and gained a cult following, particularly in the aftermath of Lucas' success with Star Wars in 1977.