Atomic physics

Atomic physics is the field of physics that studies atoms as an isolated system of electrons and an atomic nucleus. It is concerned with the arrangement of electrons around the nucleus and the processes by which these arrangements change; this comprises ions, neutral atoms and, unless otherwise stated, it can be assumed that the term atom includes ions. The term atomic physics can be associated with nuclear power and nuclear weapons, due to the synonymous use of atomic and nuclear in standard English. Physicists distinguish between atomic physics—which deals with the atom as a system consisting of a nucleus and electrons—and nuclear physics, which studies nuclear reactions and special properties of atomic nuclei; as with many scientific fields, strict delineation can be contrived and atomic physics is considered in the wider context of atomic and optical physics. Physics research groups are so classified. Atomic physics considers atoms in isolation. Atomic models will consist of a single nucleus that may be surrounded by one or more bound electrons.

It is not concerned with the formation of molecules, nor does it examine atoms in a solid state as condensed matter. It is concerned with processes such as ionization and excitation by photons or collisions with atomic particles. While modelling atoms in isolation may not seem realistic, if one considers atoms in a gas or plasma the time-scales for atom-atom interactions are huge in comparison to the atomic processes that are considered; this means that the individual atoms can be treated as if each were in isolation, as the vast majority of the time they are. By this consideration atomic physics provides the underlying theory in plasma physics and atmospheric physics though both deal with large numbers of atoms. Electrons form notional shells around the nucleus; these are in a ground state but can be excited by the absorption of energy from light, magnetic fields, or interaction with a colliding particle. Electrons that populate a shell are said to be in a bound state; the energy necessary to remove an electron from its shell is called the binding energy.

Any quantity of energy absorbed by the electron in excess of this amount is converted to kinetic energy according to the conservation of energy. The atom is said to have undergone the process of ionization. If the electron absorbs a quantity of energy less than the binding energy, it will be transferred to an excited state. After a certain time, the electron in an excited state will "jump" to a lower state. In a neutral atom, the system will emit a photon of the difference in energy, since energy is conserved. If an inner electron has absorbed more than the binding energy a more outer electron may undergo a transition to fill the inner orbital. In this case, a visible photon or a characteristic x-ray is emitted, or a phenomenon known as the Auger effect may take place, where the released energy is transferred to another bound electron, causing it to go into the continuum; the Auger effect allows one to multiply ionize an atom with a single photon. There are rather strict selection rules as to the electronic configurations that can be reached by excitation by light — however there are no such rules for excitation by collision processes.

One of the earliest steps towards atomic physics was the recognition that matter was composed of atoms. It forms a part of the texts written in 6th century BC to 2nd century BC such as those of Democritus or Vaisheshika Sutra written by Kanad; this theory was developed in the modern sense of the basic unit of a chemical element by the British chemist and physicist John Dalton in the 18th century. At this stage, it wasn't clear what atoms were although they could be described and classified by their properties; the invention of the periodic system of elements by Mendeleev was another great step forward. The true beginning of atomic physics is marked by the discovery of spectral lines and attempts to describe the phenomenon, most notably by Joseph von Fraunhofer; the study of these lines led to the birth of quantum mechanics. In seeking to explain atomic spectra an new mathematical model of matter was revealed; as far as atoms and their electron shells were concerned, not only did this yield a better overall description, i.e. the atomic orbital model, but it provided a new theoretical basis for chemistry and spectroscopy.

Since the Second World War, both theoretical and experimental fields have advanced at a rapid pace. This can be attributed to progress in computing technology, which has allowed larger and more sophisticated models of atomic structure and associated collision processes. Similar technological advances in accelerators, magnetic field generation and lasers have assisted experimental work. Particle physics Isomeric shift Atomic engineering Bransden, BH. Physics of Atoms and Molecules. Prentice Hall. ISBN 978-0-582-35692-4. Foot, CJ. Atomic Physics. Oxford University Press. ISBN 978-0-19-850696-6. Herzberg, Gerhard. Atomic Spectra and Atomic Structure. New York: Dover. ISBN 978-0-486-60115-1. Condon, E. U. & Shortley, G. H.. The Theory of Atomic Spectra. Cambridge University Press. ISBN 978-0-521-09209-8. Cowan, Robert D.. The Theory of Atomic Structure and Spectra. University of California Press. ISBN 978-0-520-03821-9. Lindgren, I. & Morrison, J.. Atomic Many-Body Theory. Springer-Verlag. ISBN 978-0-387-16649-0. MIT-Harvard Center for Ultracold Atoms Joint Quantum Institute at University of Maryland and NIST A

Islam in Jamaica

Islam in Jamaica is a minority religious affiliation. Muslims arrived in Jamaica through waves of immigration from Africa and the Indian subcontinent, today make up a population of about 5,000 with several mosques and festivals; the first Muslims in Jamaica were West African Moors captured in the Reconquista sold as slaves to traders, brought to Jamaica on ships. Bryan Edwards and Richard Robert Madden in their works written in the late 18th and early 19th century wrote about the Muslim slaves of Jamaica and their situation, they wrote that many were able to memorize the Quran, declare the shahada, fasted and some were able to write in Arabic. Over time most of them lost their Islamic identity due to forced mixing of ethnic groups. Mu’minun of African descent belonging to the Islamic nations of Mandinka, Susu and Hausa ceaselessly tried to maintain their Islamic practices in secrecy, while working as slaves on the plantations in Jamaica. By the time the slaves were liberated, much of the Muslim faith of the past had faded, the freed slaves either picked up the faith of their slave masters.

Some Muslim slaves returned to Africa, traveled to other parts of Latin America, or were crypto-Muslims. These factors led to the virtual disappearance of Islam in Jamaica outside of the Indian community. About 16 percent of the 37,000 indentured Indian immigrants who arrived to Jamaica between 1845 and 1917 were Muslims. Muhammad Khan, who came to Jamaica in 1915 at the age of 15, built Masjid Ar-Rahman in Spanish Town in 1957, while Westmoreland's Masjid Hussein was built by Muhammad Golaub, who immigrated with his father at the age of 7; the indentured Muslims laid the foundation of the eight other masjids established in Jamaica since the 1960s, with the advent of an indigenous Jamaican Muslim community that now forms the majority of the Muslim populace on the island. The statistics for Islam in Jamaica estimate a total Muslim population of about 5,000. There are several Islamic organizations and mosques in Jamaica, including the Islamic Council of Jamaica, founded in 1981 and the Islamic Education and Dawah Center, both located in Kingston and offering classes in Islamic studies and daily prayers in congregation.

Outside Kingston organizations include Masjid Al Haq in Mandeville, Masjid Al-Ihsan in Negril, Masjid-Al-Hikmah in Ocho Rios, the Port Maria Islamic Center in Saint Mary and the Ahmadiyya Mahdi Mosque in Old Harbour. These are the main Islamic Festivals practised by Jamaican Muslims: The Ramadan Fast Ashura Id al Fitr Eid al Adha Mawlid Miraj Hijrah Islamic Horizons Sept/Oct 2001 Afroz, S.'The Jihad of 1831–1832: The Misunderstood Baptist Rebellion in Jamaica'

Viktoria Yastrebova

Viktoria Yastrebova is a Russian operatic soprano. She is a principal of the Mariinsky Theatre in Saint Petersburg, Russia. Born in Rostov on Don, Yastrebova graduated from the music faculty of the Taganrog Pedagogical Institute and in 2000, from the Rostov State Rakhmaninov Conservatoire under Khudoverdova. In 2002 she joined the Mariinsky Academy of Young Singers, in 2008 became soloist of the Mariinsky Theatre. Yastrebova is Honoured Artist of the Republic of Northern Osetia-Alania, prize-winner at the International Moniuszko Vocalists' Competition in 2004, the prize-winner at the VI International Rimsky-Korsakov Young Opera Singers' Competition in 2004. In 2009 Yastrebova made her debut at Royal Opera House in London as Oksana in Tchaikovsky's opera Cherevichki, she performs in operas and concerts in countries including Russia, the United Kingdom, the United States, Finland, Austria, Israel, France and Netherlands. She has performed at international venues and opera festivals including Carnegie Hall, John F. Kennedy Center, Festspielhaus Baden-Baden, Bayerische Staatsoper, Savonlinna Festival and Barbican Hall.

On the concert platform, Yastrebova has performed Verdi’s Requiem and Beethoven's Ninth Symphony under Valery Gergiev and Adrian Leaper. She has recorded Mahler's Eighth Symphony with Valery Gergiev. 2011 saw her debut at La Scala. The Times wrote of her, following her performance in London of Rimsky-Korsakov's Tsar Saltan in 2008, "The best of the young bunch was Viktoria Yastrebova, whose dark and powerful soprano made one wonder if the phrase “the next Anna Netrebko” might be justly deployed."Donna Anna in Don Giovanni, Micaëla in Carmen, the title role of Tosca, Cio-Cio-San in Madama Butterfly, Tatiana in Eugene Onegin, Violetta in La Traviata, Desdemona in Otello, both Mimi and Musetta in La bohème, Elettra in Idomeneo, the title role of Iolanta, Maria in Mazepa, Corinna in Il viaggio a Reims, Amelia in Simon Boccanegra, Elisabeth de Valois in Don Carlo, Nedda in I pagliacci, Freia in Das Rheingold are amongst her operatic repertoire