New Articles (Page 114)

To stay up to date you can also follow on Mastodon.

πŸ”— Klemperer rosette

πŸ”— Physics

A Klemperer rosette is a gravitational system of heavier and lighter bodies orbiting in a regular repeating pattern around a common barycenter. It was first described by W. B. Klemperer in 1962, and is a special case of a central configuration.

Klemperer described the system as follows:

Such symmetry is also possessed by a peculiar family of geometrical configurations which may be described as 'rosettes'. In these an even number of 'planets' of two (or more) kinds, one (or some) heavier than the other, but all of each set of equal mass, are placed at the corners of two (or more) interdigitating regular polygons so that the lighter and heavier ones alternate (or follow each other in a cyclic manner).

The simplest rosette would be a series of four alternating heavier and lighter bodies, 90 degrees from one another, in a rhombic configuration [Heavy, Light, Heavy, Light], where the two larger bodies have the same mass, and likewise the two smaller bodies have the same mass. The number of "mass types" can be increased, so long as the arrangement pattern is cyclic: e.g. [ 1,2,3 ... 1,2,3 ], [ 1,2,3,4,5 ... 1,2,3,4,5 ], [ 1,2,3,3,2,1 ... 1,2,3,3,2,1 ], etc.

Klemperer also mentioned octagonal and rhombic rosettes. While all Klemperer rosettes are vulnerable to destabilization, the hexagonal rosette has extra stability because the "planets" sit in each other's L4 and L5 Lagrangian points.

Discussed on

πŸ”— Bouvier Affair

πŸ”— France πŸ”— Crime πŸ”— Visual arts

The Bouvier Affair was a number of international lawsuits that started in 2015, and subsequent events. The lawsuits allege that Swiss art shipper and dealer Yves Bouvier defrauded his clients by misrepresenting the original cost of art works and subsequently overcharging them. The affair has played out in courts in Monaco, Switzerland, France, the US, Hong Kong and Singapore.

The alleged victims are "high net worth individuals" in the UK, the US, Asia and Europe, most notably Monaco-based Russian oligarch Dmitry Rybolovlev.

As of FebruaryΒ 2018, Bouvier was facing criminal charges in France, Monaco and also in Switzerland after the Geneva Prosecutor opened a new case there.

Discussed on

πŸ”— Ten Percent of the Brain Myth

πŸ”— Skepticism πŸ”— Psychology πŸ”— Neuroscience

The 10 percent of the brain myth asserts that humans generally use only 10 percent (or some other small percentage) of their brains. It has been misattributed to many celebrated people, notably Albert Einstein. By extrapolation, it is suggested that a person may harness this unused potential and increase intelligence.

Changes in grey and white matter following new experiences and learning have been shown, but it has not yet been proven what the changes are. The popular notion that large parts of the brain remain unused, and could subsequently be "activated", rests in folklore and not science. Though specific mechanisms regarding brain function remain to be fully describedβ€”e.g. memory, consciousnessβ€”the physiology of brain mapping suggests that all areas of the brain have a function and that they are used nearly all the time.

Discussed on

πŸ”— Toxic squash syndrome

πŸ”— Chemicals πŸ”— Plants

Cucurbitacin is a class of biochemical compounds that some plants – notably members of the pumpkin and gourd family, Cucurbitaceae – produce and which function as a defence against herbivores. Cucurbitacins are chemically classified as triterpenes, formally derived from cucurbitane, a triterpene hydrocarbon – specifically, from the unsaturated variant cucurbit-5-ene, or 19(10β†’9Ξ²)-abeo-10Ξ±-lanost-5-ene. They often occur as glycosides. They and their derivatives have been found in many plant families (including Brassicaceae, Cucurbitaceae, Scrophulariaceae, Begoniaceae, Elaeocarpaceae, Datiscaceae, Desfontainiaceae, Polemoniaceae, Primulaceae, Rubiaceae, Sterculiaceae, Rosaceae, and Thymelaeaceae), in some mushrooms (including Russula and Hebeloma) and even in some marine mollusks.

Cucurbitacins may be a taste deterrent in plants foraged by some animals and in some edible plants preferred by humans, like cucumbers and zucchinis. In laboratory research, cucurbitacins have cytotoxic properties and are under study for their potential biological activities.

Discussed on

πŸ”— Electret

πŸ”— Physics

An electret (formed of as a portmanteau of electr- from "electricity" and -et from "magnet") is a dielectric material that has a quasi-permanent electric charge or dipole polarisation. An electret generates internal and external electric fields, and is the electrostatic equivalent of a permanent magnet. Although Oliver Heaviside coined this term in 1885, materials with electret properties were already known to science and had been studied since the early 1700s. One particular example is the electrophorus, a device consisting of a slab with electret properties and a separate metal plate. The electrophorus was originally invented by Johan Carl Wilcke in Sweden and again by Alessandro Volta in Italy.

The name derives from "electron" and "magnet"; drawing analogy to the formation of a magnet by alignment of magnetic domains in a piece of iron. Historically, electrets were made by first melting a suitable dielectric material such as a polymer or wax that contains polar molecules, and then allowing it to re-solidify in a powerful electrostatic field. The polar molecules of the dielectric align themselves to the direction of the electrostatic field, producing a dipole electret with a permanent electrostatic bias. Modern electrets are usually made by embedding excess charges into a highly insulating dielectric, e.g. by means of an electron beam, corona discharge, injection from an electron gun, electric breakdown across a gap, or a dielectric barrier.

Discussed on

πŸ”— The first motion picture production studio: Edison’s Black Maria

πŸ”— Film πŸ”— Film/American cinema

The Black Maria ( mΙ™-RY-Ι™) was Thomas Edison's film production studio in West Orange, New Jersey. It was the world's first film studio.

Discussed on

πŸ”— Quebec Sovereignty Movement

πŸ”— Canada πŸ”— Politics πŸ”— Canada/Quebec πŸ”— Canada/Political parties and politicians in Canada

The Quebec sovereignty movement (French: Mouvement souverainiste du QuΓ©bec) is a political movement whose objective is to achieve the sovereignty of Quebec, a province of Canada since 1867, including in all matters related to any provision of Quebec's public order that is applicable on its territory. Sovereignists suggest that the people of Quebec make use of their right to self-determination – a principle that includes the possibility of choosing between integration with a third state, political association with another state or independence – so that Quebecois, collectively and by democratic means, give themselves a sovereign state with its own independent constitution.

Quebec sovereignists believe that with such a sovereign state, the Quebec nation will be better equipped to promote its own economic, social, ecological and cultural development. Quebec's sovereignist movement is based on Quebec nationalism.

Discussed on

πŸ”— 1942–1944 Musicians' Strike

πŸ”— United States πŸ”— Organized Labour πŸ”— Record Labels πŸ”— United States/American music

On August 1, 1942, the American Federation of Musicians, at the instigation of union president James C. Petrillo, began a strike against the major American record companies because of disagreements over royalty payments. Beginning at midnight, July 31, 1942, no union musician could make commercial recordings for any commercial record company. That meant that a union musician was allowed to participate on radio programs and other kinds of musical entertainment, but not in a recording session. The 1942–1944 musicians' strike remains the longest strike in entertainment history.

The strike did not affect musicians performing on live radio shows, in concerts, or, after October 27, 1943, on special recordings made by the record companies for V-Discs for distribution to the armed forces fighting World War II, because V-Discs were not available to the general public. However, the union did frequently threaten to withdraw musicians from the radio networks to punish individual network affiliates who were deemed "unfair" for violating the union's policy on recording network shows for repeat broadcasts.

The strike had a major impact on the American musical scene. At the time, union bands dominated popular music; after the strike, and partly as a result of it, the big bands began to decline and vocalists began to dominate popular music.

Discussed on

πŸ”— List of sensors

πŸ”— Technology πŸ”— Lists πŸ”— Electronics

This is a list of sensors sorted by sensor type.

Discussed on

πŸ”— Texas Sharpshooter Fallacy

πŸ”— Philosophy πŸ”— Philosophy/Logic

The Texas sharpshooter fallacy is an informal fallacy which is committed when differences in data are ignored, but similarities are overemphasized. From this reasoning, a false conclusion is inferred. This fallacy is the philosophical or rhetorical application of the multiple comparisons problem (in statistics) and apophenia (in cognitive psychology). It is related to the clustering illusion, which is the tendency in human cognition to interpret patterns where none actually exist.

The name comes from a joke about a Texan who fires some gunshots at the side of a barn, then paints a shooting target centered on the tightest cluster of hits and claims to be a sharpshooter.