Have a deep view into what people are curious about.

🔗 Sharks

Magnetic shark repellents utilize permanent magnets, which exploit the sensitivity of the Ampullae of Lorenzini in sharks and rays (electrosense). This organ is not found on bony fish (teleosts), therefore, this type of shark repellent is selective to sharks and rays. Permanent magnets do not require power input, making them ideal for use in fisheries and as bycatch reduction devices. Sharkbanz, released in 2014, is a wearable commercially available device intended for recreational users.

🔗 Computing 🔗 Perl

The WikiWikiWeb is the first-ever wiki, or user-editable website. It was launched on 25 March 1995 by its inventor, programmer Ward Cunningham, to accompany the Portland Pattern Repository website discussing software design patterns. The name WikiWikiWeb originally also applied to the wiki software that operated the website, written in the Perl programming language and later renamed to "WikiBase". The site is frequently referred to by its users as simply "Wiki", and a convention established among users of the early network of wiki sites that followed was that using the word with a capitalized W referred exclusively to the original site.

🔗 United States 🔗 Biography 🔗 United States/Massachusetts 🔗 Mammals 🔗 Zoo

Hoover (c. 1971 – July 25, 1985) was a harbor seal who was able to imitate basic human speech.

🔗 Linguistics 🔗 Energy 🔗 Linguistics/Philosophy of language

Long-time nuclear waste warning messages are intended to deter human intrusion at nuclear waste repositories in the far future, within or above the order of magnitude of 10,000 years. Nuclear semiotics is an interdisciplinary field of research, first done by the Human Interference Task Force since 1981.

A 1996 report from Sandia National Laboratories recommended that any such message should comprise four levels of increasing complexity:

• Level I: Rudimentary Information: "Something man-made is here"
• Level II: Cautionary Information: "Something man-made is here and it is dangerous"
• Level III: Basic Information: Tells what, why, when, where, who, and how
• Level IV: Complex Information: Highly detailed written records, tables, figures, graphs, maps and diagrams

🔗 Energy 🔗 Mining

Uranium mining is the process of extraction of uranium ore from the ground. The worldwide production of uranium in 2019 amounted to 53,656 tonnes. Kazakhstan, Canada, and Australia were the top three uranium producers, respectively, and together account for 68% of world production. Other countries producing more than 1,000 tonnes per year included Namibia, Niger, Russia, Uzbekistan, the United States, and China. Nearly all of the world's mined uranium is used to power nuclear power plants.

Uranium is mined by in-situ leaching (57% of world production) or by conventional underground or open-pit mining of ores (43% of production). During in-situ mining, a leaching solution is pumped down drill holes into the uranium ore deposit where it dissolves the ore minerals. The uranium-rich fluid is then pumped back to the surface and processed to extract the uranium compounds from solution. In conventional mining, ores are processed by grinding the ore materials to a uniform particle size and then treating the ore to extract the uranium by chemical leaching. The milling process commonly yields dry powder-form material consisting of natural uranium, "yellowcake," which is sold on the uranium market as U₃O₈.

🔗 Astronomy 🔗 Weather 🔗 Astronomy/Solar System 🔗 Weather/Weather 🔗 Weather/Space weather

Saturn's hexagon is a persistent approximately hexagonal cloud pattern around the north pole of the planet Saturn, located at about 78°N. The sides of the hexagon are about 14,500 km (9,000 mi) long, which is about 2,000 km (1,200 mi) longer than the diameter of Earth. The hexagon may be a bit more than 29,000 km (18,000 mi) wide, may be 300 km (190 mi) high, and may be a jet stream made of atmospheric gases moving at 320 km/h (200 mph). It rotates with a period of 10h 39m 24s, the same period as Saturn's radio emissions from its interior. The hexagon does not shift in longitude like other clouds in the visible atmosphere.

Saturn's hexagon was discovered during the Voyager mission in 1981, and was later revisited by Cassini-Huygens in 2006. During the Cassini mission, the hexagon changed from a mostly blue color to more of a golden color. Saturn's south pole does not have a hexagon, as verified by Hubble observations. It does, however, have a vortex, and there is also a vortex inside the northern hexagon. Multiple hypotheses for the hexagonal cloud pattern have been developed.

🔗 Mathematics 🔗 Biology 🔗 Physics 🔗 Plants

Tendril perversion, often referred to in context as simply perversion, is a geometric phenomenon found in helical structures such as plant tendrils, in which a helical structure forms that is divided into two sections of opposite chirality, with a transition between the two in the middle. A similar phenomenon can often be observed in kinked helical cables such as telephone handset cords.

The phenomenon was known to Charles Darwin, who wrote in 1865,

A tendril ... invariably becomes twisted in one part in one direction, and in another part in the opposite direction... This curious and symmetrical structure has been noticed by several botanists, but has not been sufficiently explained.

The term "tendril perversion" was coined by Goriely and Tabor in 1998 based on the word perversion found in the 19th Century science literature. "Perversion" is a transition from one chirality to another and was known to James Clerk Maxwell, who attributed it to the topologist J. B. Listing.

Tendril perversion can be viewed as an example of spontaneous symmetry breaking, in which the strained structure of the tendril adopts a configuration of minimum energy while preserving zero overall twist.

Tendril perversion has been studied both experimentally and theoretically. Gerbode et al. have made experimental studies of the coiling of cucumber tendrils. A detailed study of a simple model of the physics of tendril perversion was made by MacMillen and Goriely in the early 2000s. Liu et al. showed in 2014 that "the transition from a helical to a hemihelical shape, as well as the number of perversions, depends on the height to width ratio of the strip's cross-section."

Generalized tendril perversions were put forward by Silva et al., to include perversions that can be intrinsically produced in elastic filaments, leading to a multiplicity of geometries and dynamical properties.

🔗 Marketing & Advertising 🔗 Linguistics

A thought-terminating cliché (also known as a semantic stop-sign, a thought-stopper, bumper sticker logic, or cliché thinking) is a form of loaded language, commonly used to quell cognitive dissonance. Depending on context in which a phrase (or cliché) is used, it may actually be valid and not qualify as thought-terminating; it does qualify as such when its application intends to dismiss dissent or justify fallacious logic. Its only function is to stop an argument from proceeding further, in other words "end the debate with a cliche... not a point." The term was popularized by Robert Jay Lifton in his 1961 book Thought Reform and the Psychology of Totalism, who called the use of the cliché, along with "loading the language", as "The language of Non-thought".

🔗 Mathematics

In mathematics before the 1970s, the term umbral calculus referred to the surprising similarity between seemingly unrelated polynomial equations and certain "shadowy" techniques used to "prove" them. These techniques were introduced by John Blissard (1861) and are sometimes called Blissard's symbolic method. They are often attributed to Édouard Lucas (or James Joseph Sylvester), who used the technique extensively.