title: Epsilon Eridani

text: The star is estimated to be less than a billion years old. Because of its relative youth, Epsilon Eridani has a higher level of magnetic activity than the present-day Sun, with a stellar wind 30 times as strong. Its rotation period is 11.2 days at the equator. Epsilon Eridani is smaller and less massive than the Sun, and has a comparatively lower level of elements heavier than helium. It is a main-sequence star of spectral class K2, which means that energy generated at the core through nuclear fusion of hydrogen is emitted from the surface at a temperature of about , giving it an orange hue.


title: Epsilon Eridani

text: The Bayer designation ε Eridani (Latinised as Epsilon Eridani) was established in 1603 by Johann Bayer. It may be a member of the Ursa Major Moving Group of stars that share a similar motion through the Milky Way, implying these stars shared a common origin in an open cluster. Its nearest neighbour, the binary star system Luyten 726-8, will have a close encounter with Epsilon Eridani in approximately 31,500 years when they will be separated by about .


title: Epsilon Eridani

text: The motion of Epsilon Eridani along the line of sight to Earth, known as the radial velocity, has been regularly observed for more than twenty years. Periodic changes in its value yielded evidence of a giant planet, Epsilon Eridani b, orbiting the star, making it one of the closest star systems with a candidate exoplanet. The discovery of the planet has been controversial because of the amount of background noise in the radial velocity data, particularly in the early observation, but most astronomers now regard the planet as confirmed. In 2016 it was given the alternative name AEgir .


title: Epsilon Eridani

text: The Epsilon Eridani system also includes two belts of rocky asteroids: at about 3 AU and 20 AU from the star. The orbital structure could be maintained by a hypothetical second planet, which if confirmed would be called Epsilon Eridani c. Epsilon Eridani hosts an extensive outer debris disk of remnant planetesimals left over from the system's formation.


title: Epsilon Eridani

text: As one of the nearest Sun-like stars with a planet, Epsilon Eridani has been the target of several observations in the search for extraterrestrial intelligence. Epsilon Eridani appears in science fiction stories and has been suggested as a destination for interstellar travel. From Epsilon Eridani, the Sun would appear as a 2.4-magnitude star in Serpens.


title: Epsilon Eridani

text: "ε Eridani", Latinised to "Epsilon Eridani", is the star's Bayer designation. Despite being a relatively bright star, it was not given a proper name by early astronomers. It has several other catalogue designations. Upon its discovery, the planet was designated Epsilon Eridani b, following the usual designation system for extrasolar planets.


title: Epsilon Eridani

text: The planet and its host star were selected by the International Astronomical Union (IAU) as part of the NameExoWorlds competition for giving proper names to exoplanets and their host stars, for some systems that did not already have proper names. The process involved nominations by educational groups and public voting for the proposed names. In December 2015, the IAU announced the winning names were "Ran" for the star and "AEgir" for the planet. Those names had been submitted by the pupils of the 8th Grade at Mountainside Middle School in Colbert, Washington, United States. Both names derive from Norse mythology: Rán is the goddess of the sea and Ægir, her husband, is the god of the ocean.


title: Epsilon Eridani

text: The names at that point remained unofficial, but in 2016 the IAU organised a Working Group on Star Names (WGSN) to catalogue and standardise proper names for stars. In its first bulletin of July 2016, the WGSN explicitly recognised the names of exoplanets and their host stars that were produced by the competition. Epsilon Eridani is now listed as Ran in the IAU Catalog of Star Names. It is not yet clear whether professional astronomers will generally use the new name, or continue to refer to the star as Epsilon Eridani; both are now equally valid.


title: Epsilon Eridani

text: In Chinese, (), meaning "Celestial Meadows", refers to an asterism consisting of ε Eridani, γ Eridani, δ Eridani, π Eridani, ζ Eridani, η Eridani, π Ceti, τ Eridani, τ Eridani, τ Eridani, τ Eridani, τ Eridani, τ Eridani, τ Eridani, τ Eridani and τ Eridani. Consequently, the Chinese name for ε Eridani itself is (, the Fourth [Star] of Celestial Meadows.)


title: Epsilon Eridani

text: Epsilon Eridani has been known to astronomers since at least the 2nd century AD, when Claudius Ptolemy (a Greek astronomer from Alexandria, Egypt) included it in his catalogue of more than a thousand stars. The catalogue was published as part of his astronomical treatise the "Almagest". The constellation Eridanus was named by Ptolemy (, River), and Epsilon Eridani was listed as its thirteenth star. Ptolemy called Epsilon Eridani , (here is the number four). This refers to a group of four stars in Eridanus: γ, π, δ and ε (10th–13th in Ptolemy's list). ε is the most western of these, and thus the first of the four in the apparent daily motion of the sky from east to west. Modern scholars of Ptolemy's catalogue designate its entry as ""P 784"" (in order of appearance) and ""Eri 13"". Ptolemy described the star's magnitude as 3.


title: Epsilon Eridani

text: Epsilon Eridani was included in several star catalogues of medieval Islamic astronomical treatises, which were based on Ptolemy's catalogue: in Al-Sufi's "Book of Fixed Stars", published in 964, Al-Biruni's "Mas'ud Canon", published in 1030, and Ulugh Beg's "Zij-i Sultani", published in 1437. Al-Sufi's estimate of Epsilon Eridani's magnitude was 3. Al-Biruni quotes magnitudes from Ptolemy and Al-Sufi (for Epsilon Eridani he quotes the value 4 for both Ptolemy's and Al-Sufi's magnitudes; original values of both these magnitudes are 3). Its number in order of appearance is 786. Ulugh Beg carried out new measurements of Epsilon Eridani's coordinates in his observatory at Samarkand, and quotes magnitudes from Al-Sufi (3 for Epsilon Eridani). The modern designations of its entry in Ulugh Beg's catalogue are ""U 781"" and ""Eri 13"" (the latter is the same as Ptolemy's catalogue designation).


title: Epsilon Eridani

text: In 1598 Epsilon Eridani was included in Tycho Brahe's star catalogue, republished in 1627 by Johannes Kepler as part of his "Rudolphine Tables". This catalogue was based on Tycho Brahe's observations of 1577–1597, including those on the island of Hven at his observatories of Uraniborg and Stjerneborg. The sequence number of Epsilon Eridani in the constellation Eridanus was 10, and it was designated , ; the meaning is the same as Ptolemy's description. Brahe assigned it magnitude 3.


title: Epsilon Eridani

text: Epsilon Eridani's Bayer designation was established in 1603 as part of the "Uranometria", a star catalogue produced by German celestial cartographer Johann Bayer. His catalogue assigned letters from the Greek alphabet to groups of stars belonging to the same visual magnitude class in each constellation, beginning with alpha (α) for a star in the brightest class. Bayer made no attempt to arrange stars by relative brightness within each class. Thus, although Epsilon is the fifth letter in the Greek alphabet, the star is the tenth-brightest in Eridanus. In addition to the letter ε, Bayer had given it the number 13 (the same as Ptolemy's catalogue number, as were many of Bayer's numbers) and described it as , . Bayer assigned Epsilon Eridani magnitude 3.


title: Epsilon Eridani

text: In 1690 Epsilon Eridani was included in the star catalogue of Johannes Hevelius. Its sequence number in constellation Eridanus was 14, its designation was ("the third"), and it was assigned magnitude 3 or 4 (sources differ). The star catalogue of English astronomer John Flamsteed, published in 1712, gave Epsilon Eridani the Flamsteed designation of 18 Eridani, because it was the eighteenth catalogued star in the constellation of Eridanus by order of increasing right ascension. In 1818 Epsilon Eridani was included in Friedrich Bessel's catalogue, based on James Bradley's observations from 1750–1762, and at magnitude 4. It also appeared in Nicolas Louis de Lacaille's catalogue of 398 principal stars, whose 307-star version was published in 1755 in the , and whose full version was published in 1757 in ", Paris". In its 1831 edition by Francis Baily, Epsilon Eridani has the number 50. Lacaille assigned it magnitude 3.


title: Epsilon Eridani

text: In 1801 Epsilon Eridani was included in , Joseph Jérôme Lefrançois de Lalande's catalogue of about 50,000 stars, based on his observations of 1791–1800, in which observations are arranged in time order. It contains three observations of Epsilon Eridani. In 1847, a new edition of Lalande's catalogue was published by Francis Baily, containing the majority of its observations, in which the stars were numbered in order of right ascension. Because every observation of each star was numbered and Epsilon Eridani was observed three times, it got three numbers: 6581, 6582 and 6583. (Today numbers from this catalogue are used with the prefix "Lalande", or "Lal".) Lalande assigned Epsilon Eridani magnitude 3. Also in 1801 it was included in the catalogue of Johann Bode, in which about 17,000 stars were grouped into 102 constellations and numbered (Epsilon Eridani got the number 159 in the constellation Eridanus). Bode's catalogue was based on observations of various astronomers, including Bode himself, but mostly on Lalande's and Lacaille's (for the southern sky). Bode assigned Epsilon Eridani magnitude 3. In 1814 Giuseppe Piazzi published the second edition of his star catalogue (its first edition was published in 1803), based on observations during 1792–1813, in which more than 7000 stars were grouped into 24 hours (0–23). Epsilon Eridani is number 89 in hour 3. Piazzi assigned it magnitude 4. In 1918 Epsilon Eridani appeared in the Henry Draper Catalogue with the designation HD 22049 and a preliminary spectral classification of K0.


title: Epsilon Eridani

text: Based on observations between 1800 and 1880, Epsilon Eridani was found to have a large proper motion across the celestial sphere, which was estimated at three arcseconds per year (angular velocity). This movement implied it was relatively close to the Sun, making it a star of interest for the purpose of stellar parallax measurements. This process involves recording the position of Epsilon Eridani as Earth moves around the Sun, which allows a star's distance to be estimated. From 1881 to 1883, American astronomer William L. Elkin used a heliometer at the Royal Observatory at the Cape of Good Hope, South Africa, to compare the position of Epsilon Eridani with two nearby stars. From these observations, a parallax of was calculated. By 1917, observers had refined their parallax estimate to 0.317 arcseconds. The modern value of 0.3109 arcseconds is equivalent to a distance of about .


title: Epsilon Eridani

text: Based on apparent changes in the position of Epsilon Eridani between 1938 and 1972, Peter van de Kamp proposed that an unseen companion with an orbital period of 25 years was causing gravitational perturbations in its position. This claim was refuted in 1993 by Wulff-Dieter Heintz and the false detection was blamed on a systematic error in the photographic plates.


title: Epsilon Eridani

text: Launched in 1983, the space telescope IRAS detected infrared emissions from stars near to the Sun, including an excess infrared emission from Epsilon Eridani. The observations indicated a disk of fine-grained cosmic dust was orbiting the star; this debris disk has since been extensively studied. Evidence for a planetary system was discovered in 1998 by the observation of asymmetries in this dust ring. The clumping in the dust distribution could be explained by gravitational interactions with a planet orbiting just inside the dust ring.


title: Epsilon Eridani

text: In 1987, the detection of an orbiting planetary object was announced by Bruce Campbell, Gordon Walker and Stephenson Yang. From 1980 to 2000, a team of astronomers led by Artie P. Hatzes made radial velocity observations of Epsilon Eridani, measuring the Doppler shift of the star along the line of sight. They found evidence of a planet orbiting the star with a period of about seven years. Although there is a high level of noise in the radial velocity data due to magnetic activity in its photosphere, any periodicity caused by this magnetic activity is expected to show a strong correlation with variations in emission lines of ionized calcium (the Ca II H and K lines). Because no such correlation was found, a planetary companion was deemed the most likely cause. This discovery was supported by astrometric measurements of Epsilon Eridani made between 2001 and 2003 with the Hubble Space Telescope, which showed evidence for gravitational perturbation of Epsilon Eridani by a planet.


title: Epsilon Eridani

text: Astrophysicist Alice C. Quillen and her student Stephen Thorndike performed computer simulations of the structure of the dust disk around Epsilon Eridani. Their model suggested that the clumping of the dust particles could be explained by the presence of a second planet in an eccentric orbit, which they announced in 2002.


title: Epsilon Eridani

text: In 1960, physicists Philip Morrison and Giuseppe Cocconi proposed that extraterrestrial civilisations might be using radio signals for communication. Project Ozma, led by astronomer Frank Drake, used the Tatel Telescope to search for such signals from the nearby Sun-like stars Epsilon Eridani and Tau Ceti. The systems were observed at the emission frequency of neutral hydrogen, 1,420 MHz (21 cm). No signals of intelligent extraterrestrial origin were detected. Drake repeated the experiment in 2010, with the same negative result. Despite this lack of success, Epsilon Eridani made its way into science fiction literature and television shows for many years following news of Drake's initial experiment.


title: Epsilon Eridani

text: In "Habitable Planets for Man", a 1964 RAND Corporation study by space scientist Stephen H. Dole, the probability of a habitable planet being in orbit around Epsilon Eridani were estimated at 3.3%. Among the known nearby stars, it was listed with the 14 stars that were thought most likely to have a habitable planet.


title: Epsilon Eridani

text: William I. McLaughlin proposed a new strategy in the search for extraterrestrial intelligence (SETI) in 1977. He suggested that widely observable events such as nova explosions might be used by intelligent extraterrestrials to synchronise the transmission and reception of their signals. This idea was tested by the National Radio Astronomy Observatory in 1988, which used outbursts of Nova Cygni 1975 as the timer. Fifteen days of observation showed no anomalous radio signals coming from Epsilon Eridani.


title: Epsilon Eridani

text: Because of the proximity and Sun-like properties of Epsilon Eridani, in 1985 physicist and author Robert L. Forward considered the system as a plausible target for interstellar travel. The following year, the British Interplanetary Society suggested Epsilon Eridani as one of the targets in its Project Daedalus study. The system has continued to be among the targets of such proposals, such as Project Icarus in 2011.


title: Epsilon Eridani

text: Based on its nearby location, Epsilon Eridani was among the target stars for Project Phoenix, a 1995 microwave survey for signals from extraterrestrial intelligence. The project had checked about 800 stars by 2004 but had not yet detected any signals.


title: Epsilon Eridani

text: At a distance of , Epsilon Eridani is the 13th-nearest known star (and ninth nearest solitary star or stellar system) to the Sun as of 2014. Its proximity makes it one of the most studied stars of its spectral type. Epsilon Eridani is located in the northern part of the constellation Eridanus, about 3° east of the slightly brighter star Delta Eridani. With a declination of −9.46°, Epsilon Eridani can be viewed from much of Earth's surface, at suitable times of year. Only to the north of latitude 80° N is it permanently hidden below the horizon. The apparent magnitude of 3.73 can make it difficult to observe from an urban area with the unaided eye, because the night skies over cities are obscured by light pollution.


title: Epsilon Eridani

text: Epsilon Eridani has an estimated mass of 0.82 solar masses and a radius of 0.74 solar radii. It shines with a luminosity of only 0.34 solar luminosities. The estimated effective temperature is 5,084 K. With a stellar classification of K2 V, it is the second-nearest K-type main-sequence star (after Alpha Centauri B). Since 1943 the spectrum of Epsilon Eridani has served as one of the stable anchor points by which other stars are classified. Its metallicity, the fraction of elements heavier than helium, is slightly lower than the Sun's. In Epsilon Eridani's chromosphere, a region of the outer atmosphere just above the light emitting photosphere, the abundance of iron is estimated at 74% of the Sun's value. The proportion of lithium in the atmosphere is five times less than that in the Sun.


title: Epsilon Eridani

text: Epsilon Eridani's K-type classification indicates that the spectrum has relatively weak absorption lines from absorption by hydrogen (Balmer lines) but strong lines of neutral atoms and singly ionized calcium (Ca II). The luminosity class V (dwarf) is assigned to stars that are undergoing thermonuclear fusion of hydrogen in their core. For a K-type main-sequence star, this fusion is dominated by the proton–proton chain reaction, in which a series of reactions effectively combines four hydrogen nuclei to form a helium nucleus. The energy released by fusion is transported outward from the core through radiation, which results in no net motion of the surrounding plasma. Outside of this region, in the envelope, energy is carried to the photosphere by plasma convection, where it then radiates into space.


title: Epsilon Eridani

text: Epsilon Eridani has a higher level of magnetic activity than the Sun, and thus the outer parts of its atmosphere (the chromosphere and corona) are more dynamic. The average magnetic field strength of Epsilon Eridani across the entire surface is , which is more than forty times greater than the magnetic-field strength in the Sun's photosphere. The magnetic properties can be modelled by assuming that regions with a magnetic flux of about 0.14 T randomly cover approximately 9% of the photosphere, whereas the remainder of the surface is free of magnetic fields. The overall magnetic activity of Epsilon Eridani shows co-existing and year activity cycles. Assuming that its radius does not change over these intervals, the long-term variation in activity level appears to produce a temperature variation of 15 K, which corresponds to a variation in visual magnitude (V) of 0.014.


title: Epsilon Eridani

text: The magnetic field on the surface of Epsilon Eridani causes variations in the hydrodynamic behaviour of the photosphere. This results in greater jitter during measurements of its radial velocity. Variations of were measured over a 20 year period, which is much higher than the measurement uncertainty of . This makes interpretation of periodicities in the radial velocity of Epsilon Eridani, such as those caused by an orbiting planet, more difficult.


title: Epsilon Eridani

text: Epsilon Eridani is classified as a BY Draconis variable because it has regions of higher magnetic activity that move into and out of the line of sight as it rotates. Measurement of this rotational modulation suggests that its equatorial region rotates with an average period of 11.2 days, which is less than half of the rotation period of the Sun. Observations have shown that Epsilon Eridani varies as much as 0.050 in V magnitude due to starspots and other short-term magnetic activity. Photometry has also shown that the surface of Epsilon Eridani, like the Sun, is undergoing differential rotation i.e. the rotation period at equator differs from that at high latitude. The measured periods range from 10.8 to 12.3 days. The axial tilt of Epsilon Eridani toward the line of sight from Earth is highly uncertain: estimates range from 24° to 72°.


title: Epsilon Eridani

text: The high levels of chromospheric activity, strong magnetic field, and relatively fast rotation rate of Epsilon Eridani are characteristic of a young star. Most estimates of the age of Epsilon Eridani place it in the range from 200 million to 800 million years. The low abundance of heavy elements in the chromosphere of Epsilon Eridani usually indicates an older star, because the interstellar medium (out of which stars form) is steadily enriched by heavier elements produced by older generations of stars. This anomaly might be caused by a diffusion process that has transported some of the heavier elements out of the photosphere and into a region below Epsilon Eridani's convection zone.


title: Epsilon Eridani

text: The X-ray luminosity of Epsilon Eridani is about (). It is more luminous in X-rays than the Sun at peak activity. The source for this strong X-ray emission is Epsilon Eridani's hot corona. Epsilon Eridani's corona appears larger and hotter than the Sun's, with a temperature of , measured from observation of the corona's ultraviolet and X-ray emission. It displays a cyclical variation in X-ray emission that is consistent with the magnetic activity cycle.


title: Epsilon Eridani

text: The stellar wind emitted by Epsilon Eridani expands until it collides with the surrounding interstellar medium of diffuse gas and dust, resulting in a bubble of heated hydrogen gas (an astrosphere, the equivalent of the heliosphere that surrounds the Sun). The absorption spectrum from this gas has been measured with the Hubble Space Telescope, allowing the properties of the stellar wind to be estimated. Epsilon Eridani's hot corona results in a mass loss rate in Epsilon Eridani's stellar wind that is 30 times higher than the Sun's. This stellar wind generates the astrosphere that spans about and contains a bow shock that lies from Epsilon Eridani. At its estimated distance from Earth, this astrosphere spans 42 arcminutes, which is wider than the apparent size of the full Moon.


title: Epsilon Eridani

text: Epsilon Eridani has a high proper motion, moving −0.976 arcseconds per year in right ascension (the celestial equivalent of longitude) and 0.018 arcseconds per year in declination (celestial latitude), for a combined total of 0.962 arcseconds per year. The star has a radial velocity of (away from the Sun). The space velocity components of Epsilon Eridani in the galactic co-ordinate system are = , which means that it is travelling within the Milky Way at a mean galactocentric distance of 28.7 kly (8.79 kiloparsecs) from the core along an orbit that has an eccentricity of 0.09. The velocity and heading of Epsilon Eridani indicate that it may be a member of the Ursa Major Moving Group, whose members share a common motion through space. This behaviour suggests that the moving group originated in an open cluster that has since diffused. The estimated age of this group is years, which lies within the range of the age estimates for Epsilon Eridani.


title: Epsilon Eridani

text: During the past million years, three stars are believed to have come within of Epsilon Eridani. The most recent and closest of these encounters was with Kapteyn's Star, which approached to a distance of about roughly 12,500 years ago. Two more distant encounters were with Sirius and Ross 614. None of these encounters are thought to have been close enough to affect the circumstellar disk orbiting Epsilon Eridani.


title: Epsilon Eridani

text: Epsilon Eridani made its closest approach to the Sun about 105,000 years ago, when they were separated by . Based upon a simulation of close encounters with nearby stars, the binary star system Luyten 726-8, which includes the variable star UV Ceti, will encounter Epsilon Eridani in approximately 31,500 years at a minimum distance of about 0.9 ly (0.29 parsecs). They will be less than 1 ly (0.3 parsecs) apart for about 4,600 years. If Epsilon Eridani has an Oort cloud, Luyten 726-8 could gravitationally perturb some of its comets with long orbital periods.


title: Epsilon Eridani

text: Observations with the James Clerk Maxwell Telescope at a wavelength of 850 μm show an extended flux of radiation out to an angular radius of 35 arcseconds around Epsilon Eridani. The peak emission occurs at an angular radius of 18 arcseconds, which corresponds to a radius of about 60 AU. The highest level of emission occurs over the radius 35–75 AU from Epsilon Eridani and is substantially reduced inside 30 AU. This emission is interpreted as coming from a young analogue of the Solar System's Kuiper belt: a compact dusty disk structure surrounding Epsilon Eridani. From Earth, this belt is viewed at an inclination of roughly 25° to the line of sight.


title: Epsilon Eridani

text: Dust and possibly water ice from this belt migrates inward because of drag from the stellar wind and a process by which stellar radiation causes dust grains to slowly spiral toward Epsilon Eridani, known as the Poynting–Robertson effect. At the same time, these dust particles can be destroyed through mutual collisions. The time scale for all of the dust in the disk to be cleared away by these processes is less than Epsilon Eridani's estimated age. Hence, the current dust disk must have been created by collisions or other effects of larger parent bodies, and the disk represents a late stage in the planet-formation process. It would have required collisions between 11 Earth masses' worth of parent bodies to have maintained the disk in its current state over its estimated age.


title: Epsilon Eridani

text: The disk contains an estimated mass of dust equal to a sixth of the mass of the Moon, with individual dust grains exceeding 3.5 μm in size at a temperature of about 55 K. This dust is being generated by the collision of comets, which range up to 10 to 30 km in diameter and have a combined mass of 5 to 9 times that of Earth. This is similar to the estimated 10 Earth masses in the primordial Kuiper belt. The disk around Epsilon Eridani contains less than of carbon monoxide. This low level suggests a paucity of volatile-bearing comets and icy planetesimals compared to the Kuiper belt.


title: Epsilon Eridani

text: The clumpy structure of the dust belt may be explained by gravitational perturbation from a planet, dubbed Epsilon Eridani c. The clumps in the dust occur at orbits that have an integer resonance with the orbit of the suspected planet. For example, the region of the disk that completes two orbits for every three orbits of a planet is in a 3:2 orbital resonance. In computer simulations the ring morphology can be reproduced by the capture of dust particles in 5:3 and 3:2 orbital resonances with a planet that has an orbital eccentricity of about 0.3. Alternatively, the clumpiness may have been caused by collisions between minor planets known as plutinos.


title: Epsilon Eridani

text: Observations from NASA's Spitzer Space Telescope suggest that Epsilon Eridani actually has two asteroid belts and a cloud of exozodiacal dust. The latter is an analogue of the zodiacal dust that occupies the plane of the Solar System. One belt sits at approximately the same position as the one in the Solar System, orbiting at a distance of from Epsilon Eridani, and consists of silicate grains with a diameter of 3 μm and a combined mass of about 10 kg. If the planet Epsilon Eridani b exists then this belt is unlikely to have had a source outside the orbit of the planet, so the dust may have been created by fragmentation and cratering of larger bodies such as asteroids. The second, denser belt, most likely also populated by asteroids, lies between the first belt and the outer comet disk. The structure of the belts and the dust disk suggests that more than two planets in the Epsilon Eridani system are needed to maintain this configuration.


title: Epsilon Eridani

text: In an alternative scenario, the exozodiacal dust may be generated in an outer belt that is orbiting between 55 and 90 AU from Epsilon Eridani and has an assumed mass of 10 times the mass of Earth. This dust is then transported inward past the orbit of Epsilon Eridani b. When collisions between the dust grains are taken into account, the dust will reproduce the observed infrared spectrum and brightness. Outside the radius of ice sublimation, located beyond 10 AU from Epsilon Eridani where the temperatures fall below 100 K, the best fit to the observations occurs when a mix of ice and silicate dust is assumed. Inside this radius, the dust must consist of silicate grains that lack volatiles.


title: Epsilon Eridani

text: The inner region around Epsilon Eridani, from a radius of 2.5 AU inward, appears to be clear of dust down to the detection limit of the 6.5 m MMT telescope. Grains of dust in this region are efficiently removed by drag from the stellar wind, while the presence of a planetary system may also help keep this area clear of debris. Still, this does not preclude the possibility that an inner asteroid belt may be present with a combined mass no greater than the asteroid belt in the Solar System.


title: Epsilon Eridani

text: As one of the nearest Sun-like stars, Epsilon Eridani has been the target of many attempts to search for planetary companions. Its chromospheric activity and variability mean that finding planets with the radial velocity method is difficult, because the stellar activity may create signals that mimic the presence of planets. Searches for exoplanets around Epsilon Eridani with direct imaging have been unsuccessful.


title: Epsilon Eridani

text: Infrared observation has shown there are no bodies of three or more Jupiter masses in this system, out to at least a distance of 500 AU from the host star. Planets with similar masses and temperatures as Jupiter should be detectable by Spitzer at distances beyond 80 AU. One roughly Jupiter-sized long-period planet was detected by both the radial velocity and the astrometry velocity methods, but has not yet been fully characterized by the latter as of 2021. Planets more than 150% as massive as Jupiter can be ruled out at the inner edge of the debris disk at 30–35 AU.


title: Epsilon Eridani

text: Referred to as Epsilon Eridani b, this planet was announced in 2000, but the discovery has remained controversial. A comprehensive study in 2008 called the detection "tentative" and described the proposed planet as "long suspected but still unconfirmed". Many astronomers believed the evidence is sufficiently compelling that they regard the discovery as confirmed. The discovery was questioned in 2013 because a search program at La Silla Observatory did not confirm it exists. , both the Extrasolar Planets Encyclopaedia and the NASA Exoplanet Archive list the planet as 'confirmed'.


title: Epsilon Eridani

text: Published sources remain in disagreement as to the proposed planet's basic parameters. Values for its orbital period range from 6.85 to 7.2 years. Estimates of the size of its elliptical orbit—the semimajor axis—range from 3.38 AU to 3.50 AU and approximations of its orbital eccentricity range from to .


title: Epsilon Eridani

text: If the planet exists, its mass remains unknown, but a lower limit can be estimated based on the orbital displacement of Epsilon Eridani. Only the component of the displacement along the line of sight to Earth is known, which yields a value for the formula "m" sin "i", where "m" is the mass of the planet and "i" is the orbital inclination. Estimates for the value of range from 0.60 Jupiter masses to 1.06 Jupiter masses, which sets the lower limit for the mass of the planet (because the sine function has a maximum value of 1). Taking in the middle of that range at 0.78, and estimating the inclination at 30°, this yields a value of Jupiter masses for the planet's mass.


title: Epsilon Eridani

text: Of all the measured parameters for this planet, the value for orbital eccentricity is the most uncertain. The eccentricity of 0.7 suggested by some observers is inconsistent with the presence of the proposed asteroid belt at a distance of 3 AU. If the eccentricity was this high, the planet would pass through the asteroid belt and clear it out within about ten thousand years. If the belt has existed for longer than this period, which appears likely, it imposes an upper limit on Epsilon Eridani b's eccentricity of about 0.10–0.15. If the dust disk is instead being generated from the outer debris disk, rather than from collisions in an asteroid belt, then no constraints on the planet's orbital eccentricity are needed to explain the dust distribution.


title: Epsilon Eridani

text: Computer simulations of the dusty disk orbiting Epsilon Eridani suggest that the shape of the disk may be explained by the presence of a second planet, tentatively dubbed Epsilon Eridani c. Clumping in the dust disk may occur because dust particles are being trapped in orbits that have resonant orbital periods with a planet in an eccentric orbit. The postulated Epsilon Eridani c would orbit at a distance of 40 AU, with an eccentricity of 0.3 and a period of 280 years. The inner cavity of the disk may be explained by the presence of additional planets. Current models of planet formation cannot easily explain how a planet could have been created at this distance from Epsilon Eridani. The disk is expected to have dissipated long before a giant planet could have formed. Instead, the planet may have formed at an orbital distance of about 10 AU, then migrated outward because of gravitational interaction with the disc or with other planets in the system.


title: Epsilon Eridani

text: Epsilon Eridani is a target for planet finding programs because it has properties that allow an Earth-like planet to form. Although this system was not chosen as a primary candidate for the now-canceled Terrestrial Planet Finder, it was a target star for NASA's proposed Space Interferometry Mission to search for Earth-sized planets. The proximity, Sun-like properties and suspected planets of Epsilon Eridani have also made it the subject of multiple studies on whether an interstellar probe can be sent to Epsilon Eridani.


title: Epsilon Eridani

text: The orbital radius at which the stellar flux from Epsilon Eridani matches the solar constant—where the emission matches the Sun's output at the orbital distance of the Earth—is 0.61 astronomical units (AU). That is within the maximum habitable zone of a conjectured Earth-like planet orbiting Epsilon Eridani, which currently stretches from about 0.5 to 1.0 AU. As Epsilon Eridani ages over a period of 20 billion years, the net luminosity will increase, causing this zone to slowly expand outward to about 0.6–1.4 AU. The presence of a large planet with a highly elliptical orbit in proximity to Epsilon Eridani's habitable zone reduces the likelihood of a terrestrial planet having a stable orbit within the habitable zone.


title: Epsilon Eridani

text: A young star such as Epsilon Eridani can produce large amounts of ultraviolet radiation that may be harmful to life, but on the other hand it is a cooler star than our Sun and so produces less ultraviolet radiation to start with. The orbital radius where the UV flux matches that on the early Earth lies at just under 0.5 AU. Because that is actually slightly closer to the star than the habitable zone, this has led some researchers to conclude there is not enough energy from ultraviolet radiation reaching into the habitable zone for life to ever get started around the young Epsilon Eridani.


title: R. J. Scaringe

text: Robert "RJ" Scaringe (born January 19, 1983) is an American entrepreneur and engineer, the founder and CEO of electric vehicle manufacturer Rivian. Scaringe's net worth is estimated at US$1.7 billion as of December 2021.


title: R. J. Scaringe

text: Robert Joseph Scaringe was born on January 19, 1983. His father, also named Robert Scaringe, is an engineer and founder of Mainstream Engineering Corporation. Scaringe grew up a car enthusiast, restoring them in his neighbor's garage. After learning of the great negative environmental effects of cars, however, he decided to focus his life on creating a more sustainable and environmentally friendly transportation system.


title: R. J. Scaringe

text: Scaringe grew up in Melbourne, Florida. He attended Melbourne Central Catholic High School. Scaringe received his bachelor's degree in mechanical engineering from Rensselaer Polytechnic Institute. He then received a master's degree in mechanical engineering at the Massachusetts Institute of Technology (MIT) and went on to also receive a doctorate in mechanical engineering at MIT's Sloan Automotive Lab.


title: R. J. Scaringe

text: Scaringe returned to Rockledge, Florida, and founded Mainstream Motors in 2009 as the sole employee. The company later changed its name to Rivian Automotive in 2011.


title: R. J. Scaringe

text: Scaringe is chairman of the board and has 9.5% voting power. Additionally, he has complete veto power over board decisions due to his 100% ownership of the company's class B shares. In total, Scaringe owns about 1.4% of Rivian.


title: Standards organization

text: A standards organization, standards body, standards developing organization (SDO), or standards setting organization (SSO) is an organization whose primary function is developing, coordinating, promulgating, revising, amending, reissuing, interpreting, or otherwise contributing to the usefulness of technical standards to those who employ them. Such an organization works to create uniformity across producers, consumers, government agencies, and other relevant parties regarding terminology, product specifications (e.g. size, including units of measure), protocols, and more. Its goals could include ensuring that Company A's external hard drive works on Company B's computer, an individual's blood pressure measures the same with Company C's sphygmomanometer as it does with Company D's, or that all shirts that should not be ironed have the same icon (a clothes iron crossed out with an X) on the label.


title: Standards organization

text: Most standards are voluntary in the sense that they are offered for adoption by people or industry without being mandated in law. Some standards become mandatory when they are adopted by regulators as legal requirements in particular domains, often for the purpose of safety or for consumer protection from deceitful practices.


title: Standards organization

text: The term "formal standard" refers specifically to a specification that has been approved by a standards setting organization. The term "de jure standard" refers to a standard mandated by legal requirements or refers generally to any formal standard. In contrast, the term "de facto standard" refers to a specification (or protocol or technology) that has achieved widespread use and acceptance – often without being approved by any standards organization (or receiving such approval only after it already has achieved widespread use). Examples of de facto standards that were not approved by any standards organizations (or at least not approved until after they were in widespread "de facto" use) include the Hayes command set developed by Hayes, Apple's TrueType font design and the PCL protocol used by Hewlett-Packard in the computer printers they produced.


title: Standards organization

text: Normally, the term "standards organization" is not used to refer to the individual parties participating within the standards developing organization in the capacity of founders, benefactors, stakeholders, members or contributors, who themselves may function as or lead the standards organizations.


title: Standards organization

text: The implementation of standards in industry and commerce became highly important with the onset of the Industrial Revolution and the need for high-precision machine tools and interchangeable parts. Henry Maudslay developed the first industrially practical screw-cutting lathe in 1800, which allowed for the standardization of screw thread sizes for the first time.


title: Standards organization

text: Maudslay's work, as well as the contributions of other engineers, accomplished a modest amount of industry standardization; some companies' in-house standards spread a bit within their industries. Joseph Whitworth's screw thread measurements were adopted as the first (unofficial) national standard by companies around the country in 1841. It came to be known as the British Standard Whitworth, and was widely adopted in other countries.


title: Standards organization

text: By the end of the 19th century differences in standards between companies was making trade increasingly difficult and strained. For instance, an iron and steel dealer recorded his displeasure in "The Times": "Architects and engineers generally specify such unnecessarily diverse types of sectional material or given work that anything like economical and continuous manufacture becomes impossible. In this country no two professional men are agreed upon the size and weight of a girder to employ for given work".


title: Standards organization

text: The Engineering Standards Committee was established in London in 1901 as the world's first national standards body. It subsequently extended its standardization work and became the British Engineering Standards Association in 1918, adopting the name British Standards Institution in 1931 after receiving its Royal Charter in 1929. The national standards were adopted universally throughout the country, and enabled the markets to act more rationally and efficiently, with an increased level of cooperation.


title: Standards organization

text: After the First World War, similar national bodies were established in other countries. The Deutsches Institut für Normung was set up in Germany in 1917, followed by its counterparts, the American National Standard Institute and the French Commission Permanente de Standardisation, both in 1918.


title: Standards organization

text: Several international organizations create international standards, such as Codex Alimentarius in food, the World Health Organization Guidelines in health, or ITU Recommendations in ICT and being publicly funded, are freely available for consideration and use worldwide.


title: Standards organization

text: In 1904, Crompton represented Britain at the Louisiana Purchase Exposition in St. Louis, Missouri, as part of a delegation by the Institute of Electrical Engineers. He presented a paper on standardization, which was so well received that he was asked to look into the formation of a commission to oversee the process. By 1906 his work was complete and he drew up a permanent terms for the International Electrotechnical Commission. The body held its first meeting that year in London, with representatives from 14 countries. In honour of his contribution to electrical standardization, Lord Kelvin was elected as the body's first President.


title: Standards organization

text: The International Federation of the National Standardizing Associations (ISA) was founded in 1926 with a broader remit to enhance international cooperation for all technical standards and specifications. The body was suspended in 1942 during World War II.


title: Standards organization

text: After the war, ISA was approached by the recently formed United Nations Standards Coordinating Committee (UNSCC) with a proposal to form a new global standards body. In October 1946, ISA and UNSCC delegates from 25 countries met in London and agreed to join forces to create the new International Organization for Standardization; the new organization officially began operations in February 1947.


title: Standards organization

text: Standards organizations can be classified by their role, position, and the extent of their influence on the local, national, regional, and global standardization arena.


title: Standards organization

text: By geographic designation, there are international, regional, and national standards bodies (the latter often referred to as NSBs). By technology or industry designation, there are standards developing organizations (SDOs) and also standards setting organizations (SSOs) also known as consortia. Standards organizations may be governmental, quasi-governmental or non-governmental entities. Quasi- and non-governmental standards organizations are often non-profit organizations.


title: Standards organization

text: Broadly, an international standards organization develops international standards. (This does not necessarily restrict the use of other published standards internationally.)


title: Standards organization

text: There are many international standards organizations. The three largest and most well-established such organizations are the International Organization for Standardization (ISO), the International Electrotechnical Commission (IEC), and the International Telecommunication Union (ITU), which have each existed for more than 50 years (founded in 1947, 1906, and 1865, respectively) and are all based in Geneva, Switzerland. They have established tens of thousands of standards covering almost every conceivable topic. Many of these are then adopted worldwide replacing various incompatible "homegrown" standards. Many of these standards are naturally evolved from those designed in-house within an industry, or by a particular country, while others have been built from scratch by groups of experts who sit on various technical committees (TCs). These three organizations together comprise the World Standards Cooperation (WSC) alliance.


title: Standards organization

text: ISO is composed of the national standards bodies (NSBs), one per member economy. The IEC is similarly composed of national committees, one per member economy. In some cases, the national committee to the IEC of an economy may also be the ISO member from that country or economy. ISO and IEC are private international organizations that are not established by any international treaty. Their members may be non-governmental organizations or governmental agencies, as selected by ISO and IEC (which are privately established organizations).


title: Standards organization

text: The ITU is a treaty-based organization established as a permanent agency of the United Nations, in which governments are the primary members, although other organizations (such as non-governmental organizations and individual companies) can also hold a form of direct membership status in the ITU as well. Another example of a treaty-based international standards organization with government membership is the Codex Alimentarius Commission.


title: Standards organization

text: In addition to these, a large variety of independent international standards organizations such as the ASME, the ASTM International, the International Commission on Illumination (CIE), the IEEE, the Internet Engineering Task Force (IETF), SAE International, TAPPI, the World Wide Web Consortium (W3C), and the Universal Postal Union (UPU) develop and publish standards for a variety of international uses. In many such cases, these international standards organizations are not based on the principle of one member per country. Rather, membership in such organizations is open to those interested in joining and willing to agree to the organization's by-laws – having either organizational/corporate or individual technical experts as members.


title: Standards organization

text: The Airlines Electronic Engineering Committee (AEEC) was formed in 1949 to prepare avionics system engineering standards with other aviation organizations RTCA, EUROCAE, and ICAO. The standards are widely known as the ARINC Standards.


title: Standards organization

text: Regional standards bodies also exist, such as the European Committee for Standardization (CEN), the European Committee for Electrotechnical Standardization (CENELEC), the European Telecommunications Standards Institute (ETSI), and the Institute for Reference Materials and Measurements (IRMM) in Europe, the Pacific Area Standards Congress (PASC), the Pan American Standards Commission (COPANT), the African Organisation for Standardisation (ARSO), the Arabic industrial development and mining organization (AIDMO), and others.


title: Standards organization

text: In the European Union, only standards created by CEN, CENELEC, and ETSI are recognized as "European standards" (according to Regulation (EU) No 1025/2012), and member states are required to notify the European Commission and each other about all the draft technical regulations concerning ICT products and services before they are adopted in national law. These rules were laid down in Directive 98/34/EC with the goal of providing transparency and control with regard to technical regulations.


title: Standards organization

text: Sub-regional standards organizations also exist such as the MERCOSUR Standardization Association (AMN), the CARICOM Regional Organisation for Standards and Quality (CROSQ), and the ASEAN Consultative Committee for Standards and Quality (ACCSQ), EAC East Africa Standards Committee www.eac-quality.net, and the GCC Standardization Organization (GSO) for Arab States of the Persian Gulf.


title: Standards organization

text: In general, each country or economy has a single recognized national standards body (NSB). A national standards body is likely the sole member from that economy in ISO; ISO currently has 161 members. National standards bodies usually do not prepare the technical content of standards, which instead is developed by national technical societies.


title: Standards organization

text: NSBs may be either public or private sector organizations, or combinations of the two. For example, the Standards Council of Canada is a Canadian Crown Corporation, Dirección General de Normas is a governmental agency within the Mexican Ministry of Economy, and ANSI is a 501(c)(3) non-profit U.S. organization with members from both the private and public sectors. The National Institute of Standards and Technology (NIST), the U.S. government's standards agency, cooperates with ANSI under a memorandum of understanding to collaborate on the United States Standards Strategy. The determinates of whether an NSB for a particular economy is a public or private sector body may include the historical and traditional roles that the private sector fills in public affairs in that economy or the development stage of that economy.


title: Standards organization

text: A "national standards body" (NSB) generally refers to one standardization organization that is that country’s member of the ISO. A "standards developing organization" (SDO) is one of the thousands of industry- or sector-based standards organizations that develop and publish industry specific standards. Some economies feature only an NSB with no other SDOs. Large economies like the United States and Japan have several hundred SDOs, many of which are coordinated by the central NSBs of each country (ANSI and JISC in this case). In some cases, international industry-based SDOs such as the CIE, the IEEE and the Audio Engineering Society (AES) may have direct liaisons with international standards organizations, having input to international standards without going through a national standards body. SDOs are differentiated from standards setting organizations (SSOs) in that SDOs may be accredited to develop standards using open and transparent processes.


title: Standards organization

text: Developers of technical standards are generally concerned with interface standards, which detail how products interconnect with each other, and safety standards, which established characteristics ensure that a product or process is safe for humans, animals, and the environment. The subject of their work can be narrow or broad. Another area of interest is in defining how the behavior and performance of products is measured and described in data sheets.


title: Standards organization

text: Overlapping or competing standards bodies tend to cooperate purposefully, by seeking to define boundaries between the scope of their work, and by operating in a hierarchical fashion in terms of national, regional and international scope; international organizations tend to have as members national organizations; and standards emerging at national level (such as BS 5750) can be adopted at regional levels (BS 5750 was adopted as EN 29000) and at international levels (BS 5750 was adopted as ISO 9000).


title: Standards organization

text: Unless adopted by a government, standards carry no force in law. However, most jurisdictions have truth in advertising laws, and ambiguities can be reduced if a company offers a product that is "compliant" with a standard.


title: Standards organization

text: When an organization develops standards that may be used openly, it is common to have formal rules published regarding the process. This may include:


title: Standards organization

text: Though it can be a tedious and lengthy process, formal standard setting is essential to developing new technologies. For example, since 1865, the telecommunications industry has depended on the ITU to establish the telecommunications standards that have been adopted worldwide. The ITU has created numerous telecommunications standards including telegraph specifications, allocation of telephone numbers, interference protection, and protocols for a variety of communications technologies. The standards that are created through standards organizations lead to improved product quality, ensured interoperability of competitors’ products, and they provide a technological baseline for future research and product development. Formal standard setting through standards organizations has numerous benefits for consumers including increased innovation, multiple market participants, reduced production costs, and the efficiency effects of product interchangeability. To support the standard development process, ISO published Good Standardization Practices (GSP) and the WTO Technical Barriers to Trade (TBT) Committee published the "Six Principles" guiding members in the development of international standards.


title: Standards organization

text: Some standards – such as the SIF Specification in K12 education – are managed by a non-profit organizations composed of public entities and private entities working in cooperation that then publish the standards under an open license at no charge and requiring no registration.


title: Standards organization

text: A technical library at a university may have copies of technical standards on hand. Major libraries in large cities may also have access to many technical standards.


title: Standards organization

text: Some users of standards mistakenly assume that all standards are in the public domain. This assumption is correct only for standards produced by the central governments whose publications are not amenable to copyright or to organizations that issue their standard under an open license. Any standards produced by non-governmental entities remain the intellectual property of their developers (unless specifically designed otherwise) and are protected, just like any other publications, by copyright laws and international treaties. However, the intellectual property extends only to the standard itself and not to its use. For instance if a company sells a device that is compliant with a given standard, it is not liable for further payment to the standards organization except in the special case when the organization holds patent rights or some other ownership of the intellectual property described in the standard.


title: Standards organization

text: It is, however, liable for any patent infringement by its implementation, just as with any other implementation of technology. The standards organizations give no guarantees that patents relevant to a given standard have been identified. ISO standards draw attention to this in the foreword with a statement like the following: "Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO and IEC shall not be held responsible for identifying any or all such patent rights". If the standards organization is aware that parts of a given standard fall under patent protection, it will often require the patent holder to agree to Reasonable and non-discriminatory licensing before including it in the standard. Such an agreement is regarded as a legally binding contract, as in the 2012 case "Microsoft v. Motorola".


title: Standards organization

text: The ever-quickening pace of technology evolution is now more than ever affecting the way new standards are proposed, developed and implemented.


title: Standards organization

text: Since traditional, widely respected standards organizations tend to operate at a slower pace than technology evolves, many standards they develop are becoming less relevant because of the inability of their developers to keep abreast with the technological innovation. As a result, a new class of standards setters appeared on the standardization arena: the industry consortia or standards setting organizations (SSOs), which are also referred to as private standards. Despite having limited financial resources, some of them enjoy truly international acceptance. One example is the World Wide Web Consortium (W3C), whose standards for HTML, CSS, and XML are used universally. There are also community-driven associations such as the Internet Engineering Task Force (IETF), a worldwide network of volunteers who collaborate to set standards for lower-level software solutions.


title: Standards organization

text: Some industry-driven standards development efforts don't even have a formal organizational structure. They are projects funded by large corporations. Among them are the OpenOffice.org, an Apache Software Foundation-sponsored international community of volunteers working on an open-standard software that aims to compete with Microsoft Office, and two commercial groups competing fiercely with each other to develop an industry-wide standard for high-density optical storage. Another example is the Global Food Safety Initiative where members of the Consumer Goods Forum define benchmarking requirements and recognize scheme owners using private standards for food safety.


title: Cross elasticity of demand

text: In economics, the cross elasticity of demand or cross-price elasticity of demand measures the percentage change of the quantity demanded for a good to the percentage change in the price of another good, ceteris paribus. In real life, the quantity demanded of good is dependent on not only its own price (Price elasticity of demand) but also the price of other "related" products. formula_1


title: Cross elasticity of demand

text: A negative cross elasticity denotes two products that are complements, while a positive cross elasticity denotes two products are substitutes.


title: Cross elasticity of demand

text: If products A and B are complements, an increase in the price of B leads to a decrease in the quantity demanded for A, as A is used in conjunction with B. Equivalently, if the price of product B decreases, the demand curve for product A shifts to the right reflecting an increase in A's demand, resulting in a "negative" value for the cross elasticity of demand. If A and B are substitutes, an inclination in the price of B will increase the market demand for A, as customers would easily replace B with A, like McDonald's and Domino's Pizza.


title: Cross elasticity of demand

text: For example, in response to a 10% increase in the price of printer's ink, the demand for printers would decrease by 20%, so the cross elasticity of demand would be: formula_2, which means an increase in the price of ink will decrease the demand for printers, so printers and ink are complements.


title: Cross elasticity of demand

text: The concept of "price elasticity of demand" originated by Alfred Marshall predicted relative changes between price and quantity. In the Cellophane case, Professor Stocking believed that a change in the price of one product will induce a price change of its "rivalry" in the same direction, so he firstly regarded that movement of two prices in the same direction explicitly reflects a high cross-price elasticity. However, during 1924–1940, du Pont cellophane prices moved independently from its perceived competitors' (waxed paper, vegetable parchment, etc) price; independent price movements reflect noncompetitive pricing between cellophane and its rival products. Thus, Professor Stocking's emphasis on the same movement of prices was too rigid, as the price of cellophane changed induced by three factors:


title: Cross elasticity of demand

text: In other words, the competitive relationship between two goods (cross-price elasticity) can not be simply concluded by price change, as price change arises from both cost and demand factors. Furthermore, instead of a high positive or low positive elasticity concluded by observing respective price change, cross-elasticity of demand should be either positive or negative to represent if there is a complementary or substitutive relationship between two goods.


title: Cross elasticity of demand

text: formula_4 implies two goods are substitutes. Consumers purchase more B when the price of A increases. Example: the cross elasticity of demand of butter with respect to margarine is 0.81, so 1% increase in the price of margarine will increase the demand for butter by 0.81%.


title: Cross elasticity of demand

text: formula_5 implies two goods are complements. Consumers purchase less B when the price of A increases. Example: the cross elasticity of demand of entertainment with respect to food is −0.72, so 1% increase in the price of food will decrease the demand for entertainment by 0.72%.


title: Cross elasticity of demand

text: formula_6 implies two goods are independent (a price change of good A is unrelated to demand change of good B), so changes in the price of product A have no effect on the demand for Product B. Example: bread and cloths .


title: Cross elasticity of demand

text: The higher the positive cross elasticity of demand, the more substitutable two products are; thus, the more competition between them. Similarly, the lower the negative cross elasticity of demand, the more complementary two goods are. In general, monopolies usually possess a low-positive cross elasticity of demand with respect to their competitors.


title: Cross elasticity of demand

text: If the absolute value of the cross elasticity of demand is greater than 1, the cross elasticity of demand is elastic, this means that a change in price of good A results in a more than proportionate change in quantity demanded for good B. In other words, a change in price of good A has a "relatively" high impact on the change in quantity demanded for good B.


title: Cross elasticity of demand

text: If the absolute value of the cross elasticity of demand between 1 and 0, the cross elasticity of demand is inelastic, this means that a change in price of good A results in a less than proportionate change in quantity demanded for good B. In other words, a change in price of good A has a "relatively" small impact on the change in quantity demanded for good B.


title: Cross elasticity of demand

text: If the value of the cross elasticity of demand is 1, the cross elasticity of demand is unitary, this means that a change in price of good A results in an exactly proportionate change in quantity demanded for good B.


title: Cross elasticity of demand

text: For two goods, fuel and new cars (consists of fuel consumption), are "complements"; that is, one is used with the other. In these cases the cross elasticity of demand will be "negative", as shown by the decrease in demand for cars when the price for fuel will rise. In the case of perfect substitutes, the cross elasticity of demand is equal to positive infinity (at the point when both goods can be consumed). Where the two goods are "independent", or, as described in consumer theory, if a good is independent in demand then the demand of that good is independent of the quantity consumed of all other goods available to the consumer, the cross elasticity of demand will be "zero" i.e. if the price of one good changes, there will be no change in demand for the other good.


title: Cross elasticity of demand

text: When goods are substitutable, the diversion ratio, which quantifies how much of the displaced demand for product "j" switches to product "i", is measured by the ratio of the cross-elasticity to the own-elasticity multiplied by the ratio of product "i"s demand to product "j"s demand. In the discrete case, the diversion ratio is naturally interpreted as the fraction of product "j" demand which treats product "i" as a second choice, measuring how much of the demand diverting from product "j" because of a price increase is diverted to product "i" can be written as the product of the ratio of the cross-elasticity to the own-elasticity and the ratio of the demand for product "i" to the demand for product "j". In some cases, it has a natural interpretation as the proportion of people buying product "j" who would consider product "i" their "second choice".


title: Cross elasticity of demand

text: Approximate estimates of the cross price elasticities of preference-independent bundles of goods (e.g. food and education, healthcare and clothing, etc.) can be calculated from the income elasticities of demand and market shares of individual bundles, using established models of demand based on a differential approach.


title: Cross elasticity of demand

text: An enterprise needs to understand the cross-elastic demand for a product or service. Cross-elastic demand can help enterprises set prices and identify the sensitivity of others to their products. For example, a strategic "loss leader" takes advantage of the negative cross elasticity of demand for complementary commodities to price in a counterintuitive way deliberately. A company can sell one of its goods for less than the cost of making it and thus promote sales of its complementary products. Large profits on complementary products can make up for net losses in the business of its main products. Many large companies use this strategy, such as Sony. Sony's PlayStation consoles are sold below the cost of making them encourage the sale of games. Games and consoles are almost perfectly complementary. The reduction in the price of consoles will significantly increase the demand for games. As a result, Sony can make up for its net losses in the console business by making big profits in games


title: Cross elasticity of demand

text: Besides, unique and irreplaceable products enable companies to sell their products at higher prices. Because of the uniqueness of the product, companies do not worry too much about consumers switching to other products. However, the specific price setting should also follow the demand curve of the commodity. Suppose the elasticity of demand for the product is greater than 1. In that case, it means that a slight change in the product's price will cause a significant reduction in the consumer demand for the product. Therefore, companies should first make a careful study of the elasticity of demand for their products before setting prices. It ensures a broader profit range for the company. A real-life example is Apple. Apple used iOS, which is different from Android, at the beginning of the launch of their phones. The clean and straightforward interface is an irreplaceable advantage of this system. Apple, meanwhile, has its unique text-message tone and call ringtone. In many small ways, Apple is building uniqueness. Phone users who are used to iOS develop a habit that makes it difficult to adapt to other systems, such as Android or Huawei HarmonyOS.


title: Cross elasticity of demand

text: Finally, the providers of substitutes need to be aware of the competitors of their products through detailed market research. The company can reduce the sensitivity of competitors' products by increasing customer loyalty. For example, the recently hot quality stars are invited to endorse their company's products. It can attract some of the star's loyal analysis to the product, thus increasing the overall loyalty. Alternatively, the company could spend more money on advertising to make consumers aware of the difference between its product and that of its competitors.


title: Cross elasticity of demand

text: The UK and Scottish governments intended to use price-based policy interventions, like setting minimum unit pricing and increasing taxation to reduce alcohol consumption and mediate the related harms among their population. Estimation of cross-price elasticities of alcohol in respect to other related beverages helps set price-based policy interventions, as it measures the percentage change in demand for one type of alcohol due to a 1% change in the price of another type of beverage. For example, the cross elasticity of demand for wine in respect to the price change of spirit is 0.05, which implies that a 1% price decrease for Spirit will reduce market demand for wine by 5%. Therefore, the cross elasticity of demand enables policymakers to take better control of the policy effects, thus, reducing the risk for mortality, morbidity, and other social harms caused by over-drinking.


title: Cross elasticity of demand

text: A high coefficient of negative cross-price elasticity implies that the sales of product A are decided by the sales of product B. If the demand of A  significantly depends on the demand of B, there must be a reduction in the profit of A. In this case, the cross elasticity of demand is a reminder to the firms to cautiously selecting products with high dependence on complements. On the other hand, the high-positive cross elasticity of demand reflects high substitutability of goods, which means customers' demand can be fulfilled by other products easily. Businesses that understand the implications of high-positive cross elasticity of demand can reduce their operating risk by avoiding overstock, thus, maintaining a sustainable supply chain.


title: Cross elasticity of demand

text: Knowledge of a firm's cross elasticity of demand and their competitors' allows them to map out the market, enabling them to calculate the number of rivals and the importance of their complementary (and substitute) products relative to their own. Firms can develop strategies to reduce their exposure to the risks they are imposed to by price changes of other firms, such as an increase in the price of a complement or a decrease in the price of a substitute.


title: Cross elasticity of demand

text: In markets with few competitors, cross elasticity between rivals are likely to be high, this makes firms in the market vulnerable to price competition. Horizontal integration, usually mergers, could reduce said risks by reducing competition in the market. For example, when Anheuser-Busch InBev (the world's biggest brewer at the time) acquired SABMiller (InBev's closest rival) in 2015, it was one of the biggest takeover of a British firm, creating the world's first global brewer. The takeover created a brewing empire that produces a third of the world's beer.


title: Cross elasticity of demand

text: Firms may gain better control of the market by merging with suppliers of complementary products. Developing their own complementary products is another possible solution. For example, Google developing Google Pixel is an attempt by Google to capture the smartphone market share by integrating both its software and hardware features for improved performance while being more resource efficient.


title: Cross elasticity of demand

text: Competitors may pool resources to create a joint alliance, such as Sony-Ericsson in October of 2001. Sony had a share of less than 1% in the mobile phone market; while Ericsson was the third largest market share holder. Unfortunately, Ericsson relied heavily on a single supplier, and when a fire broke out at a Phillips factory, Ericsson couldn't fulfill their orders. Sony wanted a greater market share and Ericsson wanted to avoid going out of business, hence the Sony-Ericsson joint venture was formed.


title: Cross elasticity of demand

text: Firms entering into a price fixing agreement in order to avoid price wars means they are involved in a collusion. The chances of collusion to occur is higher in markets with few competitors such as oligopolistic markets. It is illegal according to antitrust laws, even though collusive agreements may be implicit, its implication with cartels are the same.


title: The Vanquishers

text: "The Vanquishers", prefixed frequently with either "Chapter Six" or ""Flux"", is the sixth and final episode of the thirteenth series of the British science fiction television programme "Doctor Who", and of the six-episode serial known collectively as "Doctor Who: Flux". It was first broadcast on BBC One on 5 December 2021. It was written by showrunner and executive producer Chris Chibnall, and directed by Azhur Saleem.


title: The Vanquishers

text: The episode stars Jodie Whittaker as the Thirteenth Doctor, alongside Mandip Gill and John Bishop as her companions, Yasmin Khan and Dan Lewis, respectively.


title: The Vanquishers

text: The Doctor runs from Swarm, taking Tecteun's Ood with her. Swarm and Azure advance on her but the Doctor takes off her conversion plate and, as Swarm touches her, is split into three copies among the Division spacecraft, Bel's ship, and the Liverpool tunnels.


title: The Vanquishers

text: On the Division spacecraft, Azure attempts to return the Doctor's missing memories to her using the fob watch. The Doctor refuses to see them. Azure reveals her intent to engineer the Flux into a time loop of universal destruction. The Ood attempts to slow down the Flux.


title: The Vanquishers

text: In the Passenger, Vinder and Diane disrupt its internal systems and escape into another unknown environment.


title: The Vanquishers

text: Yaz, Dan, Jericho, and Williamson take out the Sontaran vanguard with lightning from a tunnel door before traveling to 2021 through another. They meet Kate Stewart who is leading a resistance against the invasion. The Doctor bargains for Claire and Jericho to help them find the final Flux event's coordinates. She takes her TARDIS from Kate.


title: The Vanquishers

text: The Doctor crashes Bel's ship into the Sontaran command headquarters. They are stopped by a force field, captured, and placed on a Sontaran ship. Karvanista reveals that during the Doctor's time in the Division, he was her companion. He cannot say more about it, under threat of a Division poison implant in his brain. The Sontarans remove the Doctor and inform Karvanista of the Lupari's extinction.


title: The Vanquishers

text: The Doctor piloting the TARDIS frees her copy from the Grand Serpent's torture device and aims it at him.


title: The Vanquishers

text: Bel downloads Sontaran transmissions offering alliance with the Cybermen and Daleks, a ruse to sacrifice them to the Flux while the Lupari shield ensconces the Sontarans. Claire escapes the ship. Jericho cannot. The Doctor rescues Vinder and Diane, and reforms the Lupari shield behind the Sontarans, leaving the Flux to consume the Sontarans, Daleks and Cybermen, as well as Jericho. The Doctor uses the Passenger, a repository of endless matter, to absorb the Flux.


title: The Vanquishers

text: Azure and Swarm bring the Doctor to Atropos to sacrifice her to Time, but since the Flux failed to free Time, Time destroys them. Time lets the Doctor go but warns of her end before reunifying her. In the tunnels, Kate and Vinder maroon the Serpent on a small asteroid through a door. Vinder and Bel decide to travel with Karvanista. Dan invites Diane on a date, but Diane refuses. The Doctor invites Dan to join her and Yaz on their travels. She deposits her fob watch deep into the TARDIS interior.


title: The Vanquishers

text: The series is the third to feature Jodie Whittaker as the Thirteenth Doctor, and Mandip Gill as Yasmin Khan, with John Bishop having joined the cast for the series as Daniel Lewis.


title: The Vanquishers

text: Azhur Saleem directed the second block, which comprised the third, fifth, and sixth episodes of the series.


title: The Vanquishers

text: "The Vanquishers" aired on 5 December 2021. The episode serves as the final part of a six-part story, entitled "Flux". In the United States the episode aired on BBC America.


title: The Vanquishers

text: The episode was watched by 3.58 million viewers overnight. The seven-day consolidated rating (counting all views across all platforms within seven days of broadcast) was 4.64 million. The episode was the sixth-highest rated programme on BBC1 for the week, and the 26th-highest programme across all channels for the week.


title: The Vanquishers

text: Martin Belam of "The Guardian" called "The Vanquishers" "a decent episode that ended what was the best, most consistent season of the Whittaker era." Louise Griffin for the "Metro" gave the episode three stars out of five, describing it as "a finale that’s enjoyable but [which] feels like it’s frantically trying to tie up loose ends as efficiently as possible." Isobel Lewis for "The Independent" also gave the episode three stars out of five, writing that ""Flux" has revelled in its own confusion, but while some bits in the middle feel like a hazy blur (the less said about episode three, the better), the pay-off is largely satisfying." Patrick Mulkern of the "Radio Times" gave the episode four stars out of five, describing the story as having "resolved satisfyingly" in an episode in which "everything but the kitchen sink, the dog basket and the loo brush was being chucked into the mix."


title: Barakah nuclear power plant

text: The Barakah nuclear power plant () is the United Arab Emirates' first nuclear power station, the first nuclear power station in the Arabian Peninsula, the second in the Persian Gulf region and the first commercial nuclear power station in the Arab World. It consists of four APR-1400 nuclear reactors (three operating, one undergoing post-construction testing). Total nameplate capacity is 5380 MW which is intended to supply up to 25% of UAE's electricity needs. The site is in the Gharbiya region of Abu Dhabi, on the coastline between the Persian Gulf and the E11 highway, 50 km west of Ruwais.


title: Barakah nuclear power plant

text: In December 2009, Emirates Nuclear Energy Corporation (ENEC) awarded a coalition led by Korea Electric Power Corporation (KEPCO) a $20 billion bid to build the first nuclear power plant in the UAE. Barakah was chosen as the site to build four APR-1400 nuclear reactors successively, with the first scheduled to start supplying electricity in 2017.


title: Barakah nuclear power plant

text: In 2011, Bloomberg reported that following detailed finance agreements, the build cost was put at $30 billion and financed with $10 billion equity, $10 billion export-credit agency debt, and $10 billion from bank and sovereign debt. South Korea may earn a further $20 billion from operation, maintenance and fuel supply contracts. A later Bloomberg report indicates the price as $25 billion.


title: Barakah nuclear power plant

text: As of 22 March 2018, the project's total cost was refined to $24.4 billion to complete. Startup of Unit 1 was delayed to late 2018.


title: Barakah nuclear power plant

text: The plant's ground-breaking ceremony was held on 14 March 2011, including Korean President Lee Myung-bak.It has 4 Units.


title: Barakah nuclear power plant

text: Construction of the first unit was begun in the afternoon of 18 July 2012, ahead of its scheduled date in late 2012. This happened despite delays being mooted in the wake of the Fukushima Daiichi nuclear disaster.


title: Barakah nuclear power plant

text: In May 2013, construction started on the second unit, which was then expected to take five years. The first safety-related concrete was poured for Unit 3 in September 2014. Unit 4 started construction in September 2015.


title: Barakah nuclear power plant

text: In 2014, the Barakah 1 reactor vessel was delivered onsite and site preparation works for Barakah 3 and 4 started. Meanwhile, the concrete-and-steel reactor containment building for Barakah 1 was completed in January 2015.


title: Barakah nuclear power plant

text: In March 2015, ENEC applied to Federal Authority for Nuclear Regulation (FANR) for operating licences for Units 1 and 2.


title: Barakah nuclear power plant

text: In September 2015, first concrete was poured for Unit 4. More than 18,000 staff were then working on the construction of all 4 units.


title: Barakah nuclear power plant

text: In December 2017, the rebel Houthis group claimed to have fired a cruise missile in the direction of the Barakah plant, but the Emirati authorities said that no missiles had actually reached the UAE.


title: Barakah nuclear power plant

text: In December 2018, it was reported that voids were found in the concrete containment buildings for units 2 & 3. Grease was found to have leaked through the unit 3 containment, which may have been due to a crack in the concrete.


title: Barakah nuclear power plant

text: Unit 1 was declared complete in 2018. However it was not expected to begin operations until late 2019 or early 2020. In January 2020 it was announced that fuel loading would commence that quarter, about 2.5 years later than the original planned date of August 2017. FANR had raised 400 adverse findings in a review requiring rectification of various technical, organisational and management issues.


title: Barakah nuclear power plant

text: In March 2020, ENEC announced the completion of the fuel assemblies loading into the Unit 1 reactor. The reactor started generating electricity in August 2020 and entered commercial operation in 2021.


title: Barakah nuclear power plant

text: In March 2019, Qatar lodged a letter of complaint to the International Atomic Energy Agency (IAEA) regarding the Barakah nuclear power plant, stating concerns about its safety and lack of co-operation with regional states on the project as well as that it poses a serious threat to regional stability and the environment. The UAE denied that there are safety issues with the plant stating that Barakah adheres to the highest standards of nuclear safety and security.


title: John Hoeven

text: John Henry Hoeven III ( ; born March 13, 1957) is an American banker and politician serving as the senior U.S. senator from North Dakota, a seat he has held since 2011. A member of the Republican Party, Hoeven served as the 31st governor of North Dakota from 2000 to 2010.


title: John Hoeven

text: In 2010, Hoeven was elected to the U.S. Senate, succeeding Senator Byron Dorgan, who chose not to seek reelection. Hoeven became North Dakota's senior senator in 2013 after Kent Conrad retired and was succeeded by Heidi Heitkamp, who was once Hoeven's opponent for the governor's office.


title: John Hoeven

text: Before being elected governor, Hoeven was a banker who served in numerous executive roles at various banks, most notably as president of the nation's only state-owned bank, the Bank of North Dakota, from 1993 to 2000. He is on the board of directors at First Western Bank & Trust and has an estimated net worth of $45 million, making him one of the wealthiest U.S. senators. He is the dean of North Dakota's congressional delegation.


title: John Hoeven

text: Hoeven was born in Bismarck, North Dakota, the son of Patricia "Trish" (née Chapman) and John Henry "Jack" Hoeven, Jr. His father owned a bank in Minot, North Dakota, where he worked as the president and chairman. Hoeven's ancestry is Dutch, Swedish, and English.


title: John Hoeven

text: Hoeven studied at Dartmouth College, which his father also attended. Hoeven belonged to the Alpha Chi Alpha fraternity and graduated with honors with a BA in 1979. While there, he played on the men's golf team.


title: John Hoeven

text: After Dartmouth, Hoeven attended the Kellogg School of Management at Northwestern University, graduating with an MBA in 1981.


title: John Hoeven

text: From 1986 to 1993, Hoeven was executive vice president of First Western Bank & Trust, an institution his father bought in 1970. At one time, he owned 39% of the bank’s parent company, Westbrand, Inc. From 1993 to 2000, he was the president and CEO of the Bank of North Dakota, under governor Ed Schafer.


title: John Hoeven

text: In 2000 Hoeven ran for governor of North Dakota as a Republican and won, defeating Democratic NPL nominee Heidi Heitkamp, 55% to 45%.


title: John Hoeven

text: On November 13, 2007, Hoeven announced his candidacy for a third term and kicked off his campaign with stops in Fargo, Grand Forks, Bismarck and Minot. He was reelected with 74% of the vote over Democratic-NPL nominee Tim Mathern. It was the first time in North Dakota history that a governor won three four-year terms in office, though the record for serving is still maintained by Bill Guy, who served 12 years.


title: John Hoeven

text: Hoeven's governorship included the expansion and diversification of the state's economy, which led to a 49.5% increase in the state's real gross domestic product. Beginning in 2000, he directed the development of a multi-resource energy program for the state with incentives in each energy sector, making North Dakota one of the country's largest energy-producing and exporting states. The state gained nearly 40,000 new jobs during his tenure. Wages and personal incomes grew faster than the national average. For a few years, the state led the nation in export growth. In late 2006, the state's reserve rose past $600 million, and it is now over $700 million.


title: John Hoeven

text: In December 2009, Hoeven was the country's most popular governor. His approval rating stood at 87% with only 10% disapproving. In January 2007, Hoeven became the nation's most senior governor, having been inaugurated on December 15, 2000, as established by the North Dakota Constitution.


title: John Hoeven

text: On January 11, 2010, Hoeven announced he would run in the 2010 North Dakota Senate election for the seat being vacated by Byron Dorgan. Hoeven defeated Democratic-NPL nominee Tracy Potter, 76% to 22%, making him the first Republican to represent North Dakota in the Senate since 1987.


title: John Hoeven

text: Since 2013, Hoeven has been the dean of North Dakota's congressional delegation. As of 2018, he was listed as one of the seven wealthiest U.S. senators.


title: John Hoeven

text: For his tenure as the chair of the Senate Indian Affairs Committee in the 116th Congress, Hoeven earned an F grade from the nonpartisan Lugar Center's Congressional Oversight Hearing Index.


title: John Hoeven

text: Hoeven was briefly a member of the Democratic-NPL Party before becoming active in the Republican Party as a district chair and volunteer. He has walked a conservative line on some issues and a moderate one on others, including increasing education funding, ethics reform, compensation for teachers, as well as increased funding on infrastructure. On August 10, 2021, Hoeven was one of 19 Senate Republicans to vote with the Democratic caucus in favor of the Infrastructure Investment and Jobs Act.


title: John Hoeven

text: Hoeven supports decreasing access to parole for offenders. He believes that drug control policy should be a state issue, not a federal one.


title: John Hoeven

text: Hoeven believes that alternative fuels are a long-term solution but that increased oil drilling is required in the short term. He has been a vocal advocate for the Keystone Pipeline, falsely asserting that it has never leaked and claiming that environmental risks have been exaggerated. The Keystone Pipeline has in fact leaked twice, in 2010 and in 2016.


title: John Hoeven

text: In 2015, Hoeven submitted an amendment asserting that climate change is real and that humans are contributing to it but also that the Keystone Pipeline would not contribute to climate change. His League of Conservation Voters score for 2018 was 7%.


title: John Hoeven

text: Hoeven consistently votes for pro-gun legislation and has earned an A+ rating from the National Rifle Association (NRA). The NRA has endorsed him repeatedly, including during his campaigns for governor in 2008 and senator in 2010.


title: John Hoeven

text: In June 2016, Hoeven voted on four gun control proposals that were developed as a result of the Orlando nightclub shooting. He voted for Chuck Grassley's expansion of background checks and provision of funding to research the cause of mass shootings, and for John Cornyn's 72-hour wait period for purchases of guns by people on the terrorist watchlist. He voted against Chris Murphy's proposal to require background checks for every gun sale, including online sales and at gun shows, and against Dianne Feinstein's proposal to ban anyone on the terrorist watchlist from buying a gun. Hoeven voted against the latter bill due to its lack of "judicial oversight or due process".


title: John Hoeven

text: Hoeven identifies as pro-life, opposing abortion in all cases except for rape, incest, or threat to the mother's life. He opposes government funding for elective abortions and supports the Hyde Amendment, which permits federal funding for abortion services only under the above stated exceptions. Hoeven voted to reauthorize the Violence Against Women Act in 2012.


title: John Hoeven

text: In April 2017, Hoeven co-sponsored the Israel Anti-Boycott Act (s. 720), which would bar federal contractors from participating in boycotts against Israel or Israeli settlements.


title: John Hoeven

text: In 2013, Hoeven voted for the Border Security, Economic Opportunity, and Immigration Modernization Act of 2013.


title: John Hoeven

text: In 2013, Hoeven voted against banning discrimination based on sexual orientation. He opposes same-sex marriage. In 2022, he voted against federal protections for same-sex married couples.


title: John Hoeven

text: On May 28, 2021, Hoeven voted against creating an independent commission to investigate the 2021 United States Capitol attack.


title: Joanie Loves Chachi

text: Joanie Loves Chachi is an American sitcom television series and a spin-off of "Happy Days" that aired on ABC from March 23, 1982, to May 24, 1983. It stars Erin Moran and Scott Baio as the characters Joanie Cunningham and Chachi Arcola, respectively. The series was cancelled after 17 episodes, in its second season, due to a drop in ratings.


title: Joanie Loves Chachi

text: The series is set in the early to mid-1960s and follows the exploits of Joanie and Chachi as they moved to Chicago and tried to make it on their own with a rock band and a music career at a time when the British Invasion was looming (one episode was titled "Beatlemania"). It mixed the traditional elements of a sitcom with musical performances on each show by Baio and Moran. In fact, the beginning credit sequence of the show had them singing to each other. Their backup band consists of a spaced-out drummer named Bingo and Chachi's blasé cousins Mario and Annette.


title: Joanie Loves Chachi

text: The series also starred Ellen Travolta as Louisa Delvecchio, Chachi's mother, and Al Molinaro as Al Delvecchio, Chachi's stepfather (and formerly the owner of Arnold's Drive-In in "Happy Days"), who opened a restaurant in which Chachi and Joanie performed most of their music. Art Metrano played Chachi's uncle Rico Mastorelli, who was the band's manager and helped Joanie and Chachi advance in their careers. Winifred Freedman played Rico's daughter, Annette, Chachi's cousin and bandmate.


title: Joanie Loves Chachi

text: Like other Garry Marshall related sitcoms such as "Happy Days" and "Laverne & Shirley", "Joanie Loves Chachi" had its share of anachronisms. The show was set in the 1960s yet characters were styled in a manner more true to the 1980s.


title: Joanie Loves Chachi

text: "Joanie Loves Chachi" was the first Miller-Boyett (and only Garry Marshall-produced) sitcom developed by Thomas L. Miller and Robert L. Boyett, and was created by Lowell Ganz, Mark Rothman and Garry Marshall. This is the only Garry Marshall/Miller-Boyett sitcom that does not have Charles Fox and/or Norman Gimbel as the show's theme song/music cue composer.


title: Joanie Loves Chachi

text: An urban legend circulated that the show was the highest-rated American program ever in Korea due to "chachi" being a Korean word for "penis". In actuality, the show was never broadcast to the general public of Korea, only to U.S. servicemen stationed in South Korea, and has never even been dubbed or subtitled in Korean.


title: Joanie Loves Chachi

text: Scott Baio later recalled: All the "Happy Days" people had written the first four episodes, when the show got picked up for series, but then they left to go back to "Happy Days", and we were stuck with new writers who didn’t know us. So that was a problem. And then some of the people on the show had chemical issues, and "that" was a problem. It was just on and on and on, and it just sort of all crumbled and fell apart. In retrospect, if given the choice again, I would not have done that show. That was just the wrong idea. If I had to do it all over again, I would’ve waited ’til "Happy Days" was over until I did anything else. [emphasis in original]


title: Joanie Loves Chachi

text: On February 4, 2014, CBS DVD (distributed by Paramount) released "Joanie Loves Chachi - The Complete Series" on DVD in Region 1.


title: Joanie Loves Chachi

text: The show debuted as a mid-season replacement and initially attracted high ratings, benefiting from two factors: it aired immediately following its parent series, "Happy Days", and had only reruns competing for its time slot. The ratings plummeted in Season 2 with a move to Thursday nights, which put "Joanie Loves Chachi" up against "The A-Team", and it was pulled from the schedule by the year's end. The characters were rolled back into "Happy Days" for that program's final season. ABC determined that the show was losing too much of its lead-in, suggesting low appeal if the show were moved.


title: Joanie Loves Chachi

text: The show is referenced in The Dead Milkmen song, "Swordfish" from their debut album "Big Lizard in My Backyard", released 1 June 1985. The second verse includes the line, "I believe in Joanie Loves Crotchie".


title: Joanie Loves Chachi

text: In the pilot episode of "Friends", taped on 4 May 1994, Rachel Green is watching the Happy Days episode of the main characters’ wedding after she breaks up with her fiancé Barry. She says, "See! But Joanie loved Chachi! That's the difference!"


title: Joanie Loves Chachi

text: On the Beastie Boys track "Get It Together", released on 17 March 1994, guest vocalist Q-Tip likens band member Ad Rock's close relationship with his then-wife Ione Skye to that of "Chachi and Joanie"; Ad Rock himself then replies, in rhyme, "'Cause she's the cheese and I'm the macaroni!"


title: Joanie Loves Chachi

text: In the series "Cybill", starring Cybill Shepherd as a character with her own first name is a failing actress, she frequently refers to her role on "Joanie Loves Chachi" although the actress did not appear on the show.


title: Joanie Loves Chachi

text: The show is referenced in the film "A Night at the Roxbury" (1998) where the owner of the Roxbury opens a bottle of wine from 1980, a woman says "1980, a good year" then Butabi says "Yeah, that was when "Joanie Loves Chachi" premiered" another woman named Cambi says "Yeah, yeah, "Joanie Loves Chachi", but does Chachi give a flyin' f**k bout Joanie?".


title: Joanie Loves Chachi

text: The show was referenced twice on "Family Guy", in the episode "Death Has a Shadow" (1999) a clip of the show was seen on "TV's Bloopers & Practical Jokes", where Baio (as Chachi) tries to recite the tongue-twister "Susie Sells by the Sea Shore" and gets mauled by a bear. In the episode "Save the Clam" (2013), the guys are stuck at Peter Griffin's house drinking while watching an episode of ""Joanie Loves Chris Brown"" on television.


title: Joanie Loves Chachi

text: The show is referenced in the Bloodhound Gang song, "Yummy Down on This", from their third studio album, "Hooray for Boobies" (released on 29 October 2000).


title: Joanie Loves Chachi

text: In 2002, an episode of the nostalgic documentary series "I Love the 80s" mentioned ""Joanie Loves Chachi"" as a topic.


title: Joanie Loves Chachi

text: In the film "" (2004) when White Goodman (played by Ben Stiller) hits Justin with a dodgeball, he says "Joanie loves Chachi!"


title: Joanie Loves Chachi

text: In Jason Mraz's 2018 song "Unlonely", Mraz references Chachi and Joanie in the line, "We could keep it sweet like Chachi and Joanie".


title: Osage Beach, Missouri

text: Osage Beach is a city in Camden and Miller counties in the U.S. state of Missouri. Most of the city is in Camden County, while a small eastern sliver is in Miller County. The population was 4,351 at the 2010 census.


title: Osage Beach, Missouri

text: During the 2020 COVID-19 pandemic Osage Beach gained international notoriety when on Memorial Day (May 25, 2020) a large crowd congregated at Lake of the Ozarks. The mayor at the time, John Olivarri, stated that there had been "no way to control" the situation.


title: Osage Beach, Missouri

text: According to the United States Census Bureau, the city has a total area of , of which is land and is water. The city is located on the shores of the Lake of the Ozarks.


title: Osage Beach, Missouri

text: At the 2010 census there were 4,351 people, 2,038 households, and 1,166 families living in the city. The population density was . There were 5,261 housing units at an average density of . The racial makeup of the city was 93.6% White, 1.1% African American, 0.6% Native American, 1.1% Asian, 0.2% Pacific Islander, 2.4% from other races, and 1.1% from two or more races. Hispanic or Latino of any race were 4.8%.


title: Osage Beach, Missouri

text: Of the 2,038 households 19.9% had children under the age of 18 living with them, 44.3% were married couples living together, 8.0% had a female householder with no husband present, 5.0% had a male householder with no wife present, and 42.8% were non-families. 35.3% of households were one person and 13% were one person aged 65 or older. The average household size was 2.04 and the average family size was 2.57.


title: Osage Beach, Missouri

text: The median age was 48.9 years. 15.8% of residents were under the age of 18; 8.6% were between the ages of 18 and 24; 20.2% were from 25 to 44; 31.3% were from 45 to 64; and 24% were 65 or older. The gender makeup of the city was 48.9% male and 51.1% female.