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In physics, the fine-structure constant known as Sommerfeld's constant denoted by α, is a fundamental physical constant characterizing the strength of the electromagnetic interaction between elementary charged particles. It is a dimensionless quantity related to the elementary charge e, which characterizes the strength of the coupling of an elementary charged particle with the electromagnetic field, by the formula 4πε0ħcα = e2; as a dimensionless quantity, its numerical value 1/137, is independent of the system of units used. While there are multiple physical interpretations for α, it received its name from Arnold Sommerfeld introducing it in extending the Bohr model of the atom: α quantifies the gap in the fine structure of the spectral lines of the hydrogen atom, measured by Michelson and Morley; some equivalent definitions of α in terms of other fundamental physical constants are: α = 1 4 π ε 0 e 2 ℏ c = μ 0 4 π e 2 c ℏ = k e e 2 ℏ c = c μ 0 2 R K = e 2 4 π Z 0 ℏ where: e is the elementary charge.

The definition reflects the relationship between α and the permeability of free space µ0, which equals µ0 = 2hα/ce2. In the 2019 redefinition of SI base units, 4π × 1.00000000082×10−7 H⋅m−1 is the value for µ0 based upon more accurate measurements of the fine structure constant. In electrostatic cgs units, the unit of electric charge, the statcoulomb, is defined so that the Coulomb constant, ke, or the permittivity factor, 4πε0, is 1 and dimensionless; the expression of the fine-structure constant, as found in older physics literature, becomes α = e 2 ℏ c. In natural units used in high energy physics, where ε0 = c = ħ = 1, the value of the fine-structure constant is α = e 2 4 π; as such, the fine-structure constant is just another, albeit dimensionless, quantity determining the elementary charge: e = √4πα ≈ 0.30282212 in terms of such a natural unit of charge. In atomic units, the fine structure constant is α = 1 c; the 2018 CODATA recommended value of α is α = e2/4πε0ħc = 0.0072973525693. This has a relative standard uncertainty of 0.15 parts per billion.

This value for α gives µ0 = 4π × 1.00000000054×10−7 H⋅m−1, 3.6 standard deviations away from its old defined value, but with the mean differing from the old value by only 0.54 parts per billion. For reasons of convenience the value of the reciprocal of the fine-structure constant is specified; the 2018 CODATA recommended value is given by α−1 = 137.035999084. While the value of α can be estimated from the values of the constants appearing in any of its definitions, the theory of quantum electrodynamics provides a way to measure α directly using the quantum Hall effect or the anomalous magnetic moment of the electron; the theory of QED predicts a relationship between the dimensionless magnetic moment of the electron and the fine-structure constant α. The most precise value of α obtained experimentally is based on a measurement of g using a one-electron so-called "quantum cyclotron" apparatus, together with a calculation via the theory of QED that involved 12672 tenth-order Feynman diagrams: α−1 = 137.035999174.

This measurement of α has a relative standard uncertainty of 2.5×10−10. This value and uncertainty are about the same as the latest experimental results; the fine-structure constant, α, has several physical interpretations. Α is: The square of the ratio of the elementary charge to the Planck charge α = 2. The ratio of two energies: the energy needed to overcome the electrostatic repulsion between two electrons a distance of d apart, the energy of a single photon of wavelength λ = 2πd: α = e 2 4 π ε 0 d / h

WISE 1738+2732 is a brown dwarf of spectral class Y0, located in constellation Hercules at 25.5 light-years from Earth. WISE 1738+2732 was discovered in 2011 from data, collected by Wide-field Infrared Survey Explorer Earth-orbiting satellite — NASA infrared-wavelength 40 cm space telescope, which mission lasted from December 2009 to February 2011. WISE 1738+2732 has two discovery papers: Kirkpatrick et al. and Cushing et al. however with the same authors and published nearly simultaneously. Kirkpatrick et al. presented discovery of 98 new found by WISE brown dwarf systems with components of spectral types M, L, T and Y, among, WISE 1738+2732. Cushing et al. presented discovery of seven brown dwarfs — one of T9.5 type, six of Y-type — first members of the Y spectral class discovered and spectroscopically confirmed, including "archetypal member" of the Y spectral class WISE 1828+2650, WISE 1738+2732. These seven objects are the faintest seven of 98 brown dwarfs, presented in Kirkpatrick et al..

The most accurate distance estimate of WISE 2056+1459 is a trigonometric parallax, published in 2014 by Beichman et al.: 0.128 ± 0.010 arcsec, corresponding to a distance 7.8+0.7−0.6 pc, or 25.5+2.2−1.8 ly. WISE 1738+2732 has proper motion of about 451 milliarcseconds per year; the object's temperature estimate is 350 K. Its spectrum is similar with spectrum of another Y-dwarf WISE 1405+5534. List of star systems within 25–30 light-years WISE 0148-7202 WISE 0410+1502 WISE 1405+5534 WISE 1541-2250 WISE 1828+2650 WISE 2056+1459 Marsh, Kenneth A.. "Parallaxes and Proper Motions of Ultracool Brown Dwarfs of Spectral Types Y and Late T". The Astrophysical Journal. 762: 119. ArXiv:1211.6977. Bibcode:2013ApJ...762..119M. Doi:10.1088/0004-637X/762/2/119

Driss El-Asmar is a former Morocco international football goalkeeper who played for clubs in Morocco and Greece. El-Asmar began playing club football with local side Difaa El Jadida in 1995, he moved to FAR Rabat for three seasons before returning to Difaa El Jadida for one more season before moving to play abroad. El-Asmar went to Sweden to play for second division side Degerfors IF. After a successful season, he signed a three-year contract with Malmö FF in September 2001. After his stint in Sweden, El-Asmar returned to Morocco to play for Raja Casablanca and would win the 2003–04 Botola title with the club. At age 30, he moved abroad again, signing with Ethnikos Asteras F. C. in the Greek second division in June 2006. El-Asmar made several appearances for the Morocco national football team and was selected as a reserve goalkeeper for the 1998 African Cup of Nations finals, he had a good performance in a friendly during the 2004 Africa Cup of Nations qualifying build-up in April 2003. Driss El-Asmar at National-Football-Teams.com Profile at EPAE.org

Pedro de Ribadeneira S. J. was a Spanish hagiographer, Jesuit priest, companion of Ignatius of Loyola, a Spanish Golden Age ascetic writer. Pedro was born at Spain, his father, Alvaro Ortiz de Cisneros, was the son of Pedro Gonzales Cedillo and grandson of Hernando Ortiz de Cisneros, whom Ferdinand IV had honoured with the governorship of Toledo and important missions. Pedro went to Italy as a page of Cardinal Alexander Farnese, at Rome was admitted by Ignatius of Loyola as one of the Society of Jesus on 18 September 1540, eight days before the approval of the order by Paul III, he pursued his studies at the Universities of Paris and Padua in philosophy and theology. He was ordered in November, 1549, to go to Palermo, to profess rhetoric at the new college which the Society had just opened in that city, he filled this chair for two years and a half, devoting his leisure time to visiting and consoling the sick in the hospitals. Meanwhile, St. Ignatius was negotiating the creation of the German College, during the autumn of 1552 he called on the talent and eloquence of the young professor of rhetoric at Palermo.

Ribadeneira amply fulfilled the expectations of his master and delivered the inaugural address amid the applause of an august assembly of prelates and Roman nobles. He was ordained priest 8 December 1553. During the twenty-one years which followed he filled the most important posts in the government of the order. Loyola, in 1555, sent him on a mission to Belgium. A result of his visit was his Historia Ecclesiastica del scisma del Reyno de Inglaterra reprinted, used in editions of Nicholas Sander's De Origine et Progressu Schismatis Anglicani. On 25 November 1556 he left Belgium and reached Rome on 3 February 1557, setting out again on 17 October for Flanders, his sojourn in the Low Countries was interrupted for five months. In 1560 he was made Provincial of the Society of Jesus in Tuscany transferred as Provincial to Sicily in 1563, again employed in Flanders; the accession of Father Everard Mercurian as general of the order brought a great change to Ribadeneira. His health being much impaired, he was ordered to Spain, preferably to Toledo, his native town, to recuperate.

See his autobiography in his Bibliotheca Scriptorum Societatis Jesu. This article incorporates text from a publication now in the public domain: Chisholm, Hugh, ed.. "Ribadeneira, Pedro A.". Encyclopædia Britannica. 23. Cambridge University Press. Pp. 281–282. This article incorporates text from a publication now in the public domain: Herbermann, Charles, ed.. "Pedro de Ribadeneira". Catholic Encyclopedia. New York: Robert Appleton

Chase Montgomery is an American stock car racing driver. He owns a small business and continues to pursue a racing career, he lives in Tennessee. He is now a father. Montgomery began racing go-karts at the age of 13, he began rising through the ranks quickly and by 2000, he was a regular weekly driver at Nashville Speedway USA. In 2002, he joined the ARCA Re/MAX Series, posting four top-fives and finishing 4th in points, runner-up in the Rookie of the Year points; that year, rock singer Alice Cooper came on board as a co-owner and marketing partner of his race team. The next season, he won the season opening-race at Daytona International Speedway. In 2004, he became the youngest driver to win the pole for an ARCA race. Montgomery began his NASCAR career in 2003 with 15 starts in the Busch Series with Brewco Motorsports, posting a top-ten in his series debut at the Koolerz 300. After that season came to a close, he signed to drive the No. 8 Dodge for Bobby Hamilton Racing. He finished 21st in points that year, 23rd in 2005 in the No. 18.

In 2006, he was to drive part-time for Curry Racing, after finishing the season opener at Daytona 19th, the deal fell through and Montgomery left the team. Official Website Chase Montgomery driver statistics at Racing-Reference Chase on NASCAR.com

The 2017 Bhopal–Ujjain Passenger train bombing was a terrorist attack that occurred on March 7, 2017 on the Bhopal–Ujjain Passenger, a passenger train which runs between Bhopal Junction railway station of Bhopal, the capital city of Madhya Pradesh and Ujjain Junction railway station. The bombing occurred at Jabri railway station in the Shajapur district of Madhya Pradesh, injuring 10 passengers, it was stated to be the first-ever strike in India by the Islamic State. One of the terrorist suspect was killed in an encounter in Lucknow, it was stated by the police that the module was self-radicalised and didn't receive any financial support from the group. Six persons were arrested. National Investigation Agency probe reports stated that the ISIS-inspired module had conspired to bomb a rally of Prime Minister Narendra Modi. On March 19, Indian authorities told the media that the terrorists related to this attack tried to flee India and go to Syria or Iraq. Jabri railway station List of rail accidents List of Indian rail incidents List of terrorist incidents in India List of terrorist incidents in March 2017