Have a deep view into what people are curious about.

🔗 Philately

A Royal Mail rubber band is a small red elastic loop used by the postal delivery service in the United Kingdom. In the course of its work, the Royal Mail consumes nearly one billion rubber bands per year to tie together bundles of letters at sorting offices. In the 2000s, complaints about Royal Mail rubber bands littering the streets of Britain gave rise to ongoing press interest in this minor cultural phenomenon. The Royal Mail no longer uses red rubber bands.

🔗 Mathematics

In number theory, the Green–Tao theorem, proved by Ben Green and Terence Tao in 2004, states that the sequence of prime numbers contains arbitrarily long arithmetic progressions. In other words, for every natural number k, there exist arithmetic progressions of primes with k terms. The proof is an extension of Szemerédi's theorem. The problem can be traced back to investigations of Lagrange and Waring from around 1770.

🔗 Economics 🔗 Business 🔗 Sociology 🔗 Occupations

This is a category of jobs that have been rendered obsolete due to advances in technology and/or social conditions.

🔗 Biography 🔗 Military history 🔗 Politics 🔗 Military history/Military biography 🔗 Biography/military biography 🔗 Military history/Cold War 🔗 Biography/politics and government 🔗 Military history/South American military history 🔗 Uruguay

José Alberto "Pepe" Mujica Cordano (Spanish: [xoˈse muˈxika]; born 20 May 1935) is a Uruguayan politician and farmer who served as the 40th President of Uruguay from 2010 to 2015. A former guerrilla with the Tupamaros, he was tortured and imprisoned for 14 years during the military dictatorship in the 1970s and 1980s. A member of the Broad Front coalition of left-wing parties, Mujica was Minister of Livestock, Agriculture, and Fisheries from 2005 to 2008 and a Senator afterwards. As the candidate of the Broad Front, he won the 2009 presidential election and took office as President on 1 March 2010.

He has been described as "the world's humblest head of state" due to his austere lifestyle and his donation of around 90 percent of his $12,000 monthly salary to charities that benefit poor people and small entrepreneurs. An outspoken critic of capitalism’s focus on stockpiling material possessions which do not contribute to human happiness, Pepe is often seen riding his 60-year-old bicycle. The Times Higher Education called him the "philosopher president" in 2015, a play on words of Plato's conception of the philosopher king.

The Leary–Lettvin debate was a May 3, 1967 debate between Dr. Jerome Lettvin, a medical doctor and professor at MIT, and Dr. Timothy Leary, a licensed psychologist, about the merits and dangers of the hallucinogenic drug LSD. It took place in the Kresge Auditorium at the Massachusetts Institute of Technology.

🔗 United States 🔗 Trains 🔗 United States/Ohio 🔗 Trains/Rapid transit 🔗 United States/Cincinnati

The Cincinnati Subway is a set of incomplete, derelict tunnels and stations for a rapid transit system beneath the streets of Cincinnati, Ohio. Although it is only a little over 2 miles in length, it is the largest abandoned subway tunnel system in the United States. Construction began in the early 1900s as an upgrade to the Cincinnati streetcar system, but was abandoned due to escalating costs, the collapse of funding amidst political bickering, and the Great Depression during the 1920s and 1930s.

In 1928, the construction of the subway system in Cincinnati was indefinitely canceled. There are no plans to revive the project.

🔗 United States 🔗 Aviation 🔗 Aviation/aircraft

Ballistic Recovery Systems, Inc. (commonly referred to as BRS Aerospace, or simply BRS) is a manufacturer of aircraft ballistic parachutes.

The company was formed in 1980 by Boris Popov of Saint Paul, Minnesota, after he survived a 400-foot (120 m) fall in a partially collapsed hang glider in 1975. As a result, Popov invented a parachute system that could lower an entire light aircraft to the ground in the event of loss of control, failure of the aircraft structure, or other in-flight emergencies.

Popov was granted a U.S. patent on 26 August 1986 for the so-called Ballistic Recovery System (BRS) - patent US 4607814 A.

The company has two divisions: BRS Aviation and BRS Defense.

🔗 Philosophy 🔗 Philosophy/Aesthetics 🔗 Philosophy/Social and political philosophy 🔗 Philosophy/Philosophy of religion

In a paper delivered to the Aristotelian Society on 12 March 1956, Walter Bryce Gallie (1912–1998) introduced the term essentially contested concept to facilitate an understanding of the different applications or interpretations of the sorts of abstract, qualitative, and evaluative notions—such as "art", "philanthropy" and "social justice"—used in the domains of aesthetics, development, political philosophy, philosophy of history, and philosophy of religion.

Garver (1978) describes their use as follows:

The term essentially contested concepts gives a name to a problematic situation that many people recognize: that in certain kinds of talk there is a variety of meanings employed for key terms in an argument, and there is a feeling that dogmatism ("My answer is right and all others are wrong"), skepticism ("All answers are equally true (or false); everyone has a right to his own truth"), and eclecticism ("Each meaning gives a partial view so the more meanings the better") are none of them the appropriate attitude towards that variety of meanings.

Essentially contested concepts involve widespread agreement on a concept (e.g., "fairness"), but not on the best realization thereof. They are "concepts the proper use of which inevitably involves endless disputes about their proper uses on the part of their users", and these disputes "cannot be settled by appeal to empirical evidence, linguistic usage, or the canons of logic alone".

🔗 Computing 🔗 Computer science

In computer science, the five-minute rule is a rule of thumb for deciding whether a data item should be kept in memory, or stored on disk and read back into memory when required. It was first formulated by Jim Gray and Gianfranco Putzolu in 1985, and then subsequently revised in 1997 and 2007 to reflect changes in the relative cost and performance of memory and persistent storage.

The rule is as follows:

The 5-minute random rule: cache randomly accessed disk pages that are re-used every 5 minutes or less.

Gray also issued a counterpart one-minute rule for sequential access:

The 1-minute rule: cache sequentially accessed disk pages that are re-used every 1 minute or less.

Although the 5-minute rule was invented in the realm of databases, it has also been applied elsewhere, for example, in Network File System cache capacity planning.

The original 5-minute rule was derived from the following cost-benefit computation:

BreakEvenIntervalinSeconds = (PagesPerMBofRAM / AccessesPerSecondPerDisk) × (PricePerDiskDrive / PricePerMBofRAM)

Applying it to 2007 data yields approximately a 90-minutes interval for magnetic-disk-to-DRAM caching, 15 minutes for SSD-to-DRAM caching and 2​¹⁄₄ hours for disk-to-SSD caching. The disk-to-DRAM interval was thus a bit short of what Gray and Putzolu anticipated in 1987 as the "five-hour rule" was going to be in 2007 for RAM and disks.

According to calculations by NetApp engineer David Dale as reported in The Register, the figures for disc-to-DRAM caching in 2008 were as follows: "The 50KB page break-even was five minutes, the 4KB one was one hour and the 1KB one was five hours. There needed to be a 50-fold increase in page size to cache for break-even at five minutes." Regarding disk-to-SSD caching in 2010, the same source reported that "A 250KB page break even with SLC was five minutes, but five hours with a 4KB page size. It was five minutes with a 625KB page size with MLC flash and 13 hours with a 4KB MLC page size."

In 2000, Gray and Shenoy applied a similar calculation for web page caching and concluded that a browser should "cache web pages if there is any chance they will be re-referenced within their lifetime."

🔗 Crime 🔗 Death 🔗 England 🔗 Graffiti

Who put Bella down the Wych Elm? is graffiti that appeared in 1944 following the 1943 discovery by four children of the skeletonised remains of a woman inside a wych elm in Hagley Wood, Hagley (located in the estate of Hagley Hall), in Worcestershire, England. The victim—whose murder is approximated to have occurred in 1941—remains unidentified, and the current location of her skeleton and autopsy report is unknown.