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Mytilene

Mytilene (Μυτιλήνη ) is the capital of the Greek island of Lesbos, and its port. It is also the capital and administrative center of the North Aegean Region, and hosts the headquarters of the University of the Aegean. It was founded in the 11th century BC.

Mytilene is one of the two municipalities on the island of Lesbos, created in 2019; the other is West Lesbos. Mytilene is built on the southeast edge of the island. It is the seat of a metropolitan bishop of the Eastern Orthodox Church.

History

As an ancient city, lying off the east coast, Mytilene was initially confined to a small island just offshore that later was joined to Lesbos, creating a north and south harbor. The early harbors of Mytilene were linked during ancient times by a channel 700 m long and 30 m wide. The Roman writer Longus speaks of white stone bridges linking the two sides. The Greek word εὔριπος eúripos is a commonly-used term when referring to a strait. The strait allowed ancient warships called triremes, with three tiers of rowers or more. The boats that passed were ca. 6 m wide plus oars and had depth of 2 m.

The areas of the city that were densely populated connected the two bodies of land with marble bridges. They usually followed a curved line. The strait begins at the old market called Apano Skala. It was also close to Metropolis Street and ended at the Southern Harbor. One could argue that the channel transversed what is now called Ermou Street. Over time the strait began to collect silt and earth. There was also human intervention for the protection of the Castle of Mytilene. The strait eventually filled with earth.

Mytilene contested successfully with Mithymna in the north of the island for the leadership of the island in the seventh century BC and became the centre of the island's prosperous eastern hinterland. Her most famous citizens were the poets Sappho and Alcaeus and the statesman Pittacus (one of the Seven Sages of Greece). The city was famed for its great output of electrum coins struck from the late sixth through mid-fourth centuries BC.

The Mytilenean revolt against Athens in 428 BC was overcome by an Athenian expeditionary force. The Athenian public assembly voted to massacre all the men of the city and to sell the women and children into slavery but the next day in the Mytilenian Debate changed its mind. A fast trireme sailed the 186 nmi in less than a day and brought the decision to cancel the general massacre, but a thousand citizens were executed for taking part in the rebellion.

Aristotle lived on Mytilene for two years, 337–335 BC, with his friend and successor, Theophrastus (a native of the island), after being the tutor to Alexander, son of King Philip II of Macedon.

The Romans, among whom was a young Julius Caesar, successfully defeated Mytilene in 81 BC at the Siege of Mytilene. Although Mytilene supported the losing side in most of the great wars of the first century BC, her statesmen succeeded in convincing Rome of her support of the new ruler of the Mediterranean and the city flourished in Roman times.

In AD 56, Luke the Evangelist, Paul the Apostle and their companions stopped there briefly on the return trip of Paul's third missionary journey, having sailed from Assos (about 50 km away). From Mytilene they continued towards Chios.

The novel Daphnis and Chloe by Longus, is set in the country around it and opens with a description of the city.

Scholar and historian Zacharias Rhetor, also known as Zacharias of Mytilene was from Mytilene and lived from 465 to around 536. He was made Bishop of Mytilene and may have been a Chalcedonian Christian. He either died or was deposed between 536 and 553.

The city of Mytilene was also home to 9th century Byzantine saints who were brothers, Archbishop George, Symeon Stylites, and David the Monk. The Church of St. Symeon, Mytilene venerates one of the three brothers.

Catching the eye of the Empress Zoë Porphyrogenita, Constantine IX Monomachos was exiled to Mytilene on the island of Lesbos by her second husband, Michael IV the Paphlagonian. The death of Michael IV and the overthrow of Michael V in 1042 led to Constantine being recalled from his place of exile and appointed as a judge in Greece. Lesbos and Mytilene had an established Jewish population since ancient times. In 1170, Benjamin of Tudela found ten small Jewish communities on the island.

In the Middle Ages, it was part of the Byzantine Empire and was occupied for some time by the Seljuqs under Tzachas in 1085. In 1198, the Republic of Venice obtained the right to commerce from the city's port.

In the 13th century, it was captured by the Emperor of Nicaea, Theodore I Laskaris. In 1335, the Byzantines, with the help of Ottoman forces, reconquered the island, then property of the Genoese nobleman Domenico Cattaneo. In 1355, emperor John V Palaiologos gave it to the Genoese adventurer Francesco Gattilusio, who married the emperor's sister, Maria. They renovated the fortress in 1373, and it remained in Genoese hands until 1462, when it was besieged and captured by the Ottoman sultan Mehmed the Conqueror.

As part of the wider Great Turkish War, the Battle of Mytilene took place off the coast of Mytilene in 1690 when Venetian sailing ships attacked Ottoman and Barbary flagships. Resulting in a victory for the Venetians.

Mytilene along with the rest of Lesbos remained under Ottoman control until the First Balkan War in 1912, when in November it was captured by the Kingdom of Greece.

Geography and climate
Mytilene is located in the southeastern part of the island, north and east of the Bay of Gera. Its municipal unit has a land area of 107.46 km2 and a population of 41,379 inhabitants (2021). With a population density of 390/km2 it is by far the most densely populated municipal unit in Lesbos. The next largest towns in the municipal unit are Loutrá (pop. 1,339), Pámfila (1,264), and Mória (1,237). The Greek National Road 36 connects Mytilene with Kalloni. Farmlands surround Mytilene, the mountains cover the west and to the north. The airport is located a few kilometres south of town.

Municipal units
The municipality, as created in 2019, consists of the following six subdivisions:
 * Agiasos
 * Evergetoulas
 * Gera
 * Loutropoli Thermis
 * Mytilene
 * Plomari

Each municipal unit is subdivided into municipal communities. The communities of the municipal unit of Mytilene are:
 * Afalonas
 * Agia Marina
 * Alyfanta
 * Loutra
 * Moria
 * Mytilene
 * Pamfila
 * Panagiouda
 * Taxiarches

Province
The province of Mytilene (Επαρχία Μυτιλήνης) was one of the provinces of the Lesbos Prefecture. Its territory corresponded with that of the current municipal units Mytilene, Agiasos, Evergetoulas, Gera, Loutropoli Thermis, Mantamados and Polichnitos. It was abolished in 2006.

Climate
Mytilene has a hot-summer Mediterranean climate (Köppen: Csa) with hot, dry summers and cool, rainy winters.

Districts

 * Agorá
 * Chalikas (upper and lower)
 * Chrisomallousa
 * Epano Skala
 * Kallithea
 * Kamares
 * Ladadika
 * Lagada
 * Pyrgélia
 * Sourada
 * Lazaretto/Vounaraki

Main streets

 * Ermou Street
 * Kavetsou St
 * El. Venizelou St
 * Elyti St
 * Kountourioti St
 * Theofrastou St
 * Vernardaki St,
 * Vournazon St.
 * Eftalioti St.
 * Myrivili St.

Economy

Mytilene has a port with ferries to the nearby islands of Lemnos and Chios and Ayvalık and at times Dikili in Turkey. The port also serves the mainland cities of Piraeus, Athens and Thessaloniki. One ship, named during the 2001 IAAF games in Edmonton Aeolus Kenteris, after Kostas Kenteris, used to serve this city (his hometown) with 6-hour routes from Athens and Thessaloniki. The main port serving Mytilene on the Greek mainland is Piraeus.

The city produces ouzo. There are more than 15 commercial producers on the island.

The city exports also sardines harvested from the Bay of Kalloni, olive oil, ladotyri cheese and woodwork.

Landmarks and urban architecture

The town of Mytilene has a large number of neoclassical buildings, public and private houses. Some of them are the building of the Lesbos Prefecture, the old City Hall, the Experimental Lyceum and various mansions and hotels all over the town.

The Baroque church of Saint Therapon dominates at the port with its impressive style.

 * Ancient Theatre of Mytilene
 * Archaeological Museum of Mytilene
 * Castle of Mytilene
 * Church of Saint Symeon, Mytilene
 * Catholic Church of Theotokos, where part of the relics of Saint Valentine are kept
 * Çarşı Hamam ("Market Bath")
 * Ecclesiastical Byzantine Museum of Mytilene
 * Folk Art Museum of Mytilene
 * Monastery of Agios Raphael
 * Museum of Costume and Embroidery of Lesvos
 * Sappho Square, where the statue of the Ancient Greek poet Sappho is located
 * Statue of Liberty (Mytilene)
 * Theofilos Museum
 * Yeni Mosque, Mytilene
 * Valide Mosque, Mytilene
 * The Roman aqueduct of Mória
 * Teriade Meseum
 * Agora of Ermou street
 * Stoa of Mytilene, Hellinistic stoa in the area of Epano skala

Archaeology

Archaeological investigations at Mytilene began in the late 19th century when Robert Koldewey (later excavator of Babylon) and a group of German colleagues spent many months on the island preparing plans of the visible remains at various ancient sites like Mytilene. Significant excavations, however, do not seem to have started until after the First World War when in the mid-1920s Evangelides uncovered much of the famous theatre (according to Plutarch it was the inspiration for Pompey's theatre in Rome in 55 BC, the first permanent stone theatre in Rome) on the hill on the western side of town. Subsequent work in the 1950s, 1960s and 1970s by various members of the Archaeological Service revealed more of the theatre, including a Roman conversion to a gladiatorial arena. Salvage excavations carried out by the Archaeological Service in many areas of the city have revealed sites going back to the Early Bronze Age although most have been much later (Hellenistic and Roman). Particularly significant is a large stoa over a hundred metres long recently dug on the North Harbour of the city. It is clear from various remains in different parts of the city that Mytilene was indeed laid out on a grid plan as the Roman architect Vitruvius had written.

Archaeological excavations carried out between 1984 and 1994 in the Castle of Mytilene by the University of British Columbia and directed by Caroline and Hector Williams revealed a previously unknown sanctuary of Demeter and Kore of late classical/Hellenistic date and the burial chapel of the Gattelusi, the medieval Genoese family that ruled the northern Aegean from the mid-14th to mid-15th centuries of our era. The Demeter sanctuary included five altars for sacrifices to Demeter and Kore and later also to Cybele, the great mother goddess of Anatolia. Among the discoveries were thousands of oil lamps, terracotta figurines, loom weights and other dedications to the goddesses. Numerous animal bones, especially of piglets, also appeared. The Chapel of St. John served as the church of the castle and as a burial place for the Gattelusi family and its dependents. Although conversion to a mosque after the Ottoman capture of the city in 1462 resulted in the destruction of many graves, some remained. The great earthquake of February 1867 damaged the building beyond repair and it was demolished; the Ottomans built a new mosque over the ruins to replace it later in the 19th century.

Other excavations done jointly with the 20th Ephorate of Prehistoric and Classical Antiquities near the North Harbour of the city uncovered a multiperiod site with remains extending from a late Ottoman cemetery (including a "vampire" burial, a middle aged man with 20 cm spikes through his neck, middle and ankles) to a substantial Roman building constructed around a colonnaded courtyard (probably a tavern/brothel in its final phase in the mid-4th century AD) to remains of Hellenistic structures and debris from different Hellenistic manufacturing processes (pottery, figurines, cloth making and dyeing, bronze and iron working) to archaic and classical levels with rich collections of Aeolic grey wares. A section of the late classical city wall runs across the site which was close to the channel that divided the mainland from the off shore island part of the city. Considerable remains of the two moles that protected the large North Harbour of the city are still visible just below or just breaking the surface of the sea; it functioned as the commercial harbour of the ancient city although today it is a quiet place where a few small fishing boats are moored.

The city has two excellent archaeological museums, one by the south harbour in an old mansion and the other two hundred metres further north in a large new purpose built structure. The former contains the rich Bronze Age remains from Thermi, a site north of Mytilene dug by the British in the 1930s as well as extensive pottery and figurine displays; the former coach house accommodates ancient inscriptions, architectural pieces, and coins. The latter museum is especially rich in mosaics and sculpture, including the famous late Roman mosaic floor from the "House of Menander" with scenes from plays by that Athenian 4th-century BC playwright. There are also mosaics and finds from other Roman mansions excavated by the Greek Archaeological Service under the direction of the archeologist Aglaia Archontidou-Argyri.

Education

There are 15 primary schools in Mytilene, along with seven lyceums, and eight gymnasiums. There are six university schools with 3671 undergraduates, the largest in the University of the Aegean. Here also is the Headquarters, the Central Library and the Research Committee of Aegean University. The University of Aegean is housed in privately owned buildings, in rented buildings located in the city centre and in modern buildings on the University Hill.

Refugee camps
By 2015, the city of Mytilene had become a primary entry point for refugees and migrants who seek to pass through Greece to resettle elsewhere in Europe. In 2015, over half a million people arrived in Lesbos. The number of individuals coming through Lesbos has dwindled since the signing of the EU-Turkey deal which restricted the number of refugees that could legally resettle in Europe. , seventy to eighty refugees were still arriving in Greece daily despite the deal and "many of them on Lesbos", according to Daniel Esdras, the chief of the International Organization for Migration.

 * Mória Reception & Identification Centre (in Greek : Κέντρο Υποδοχής και Ταυτοποίησης Μόριας), better known as Mória Refugee Camp, or just "Mória", was the biggest refugee camp in Europe. It was located outside the village of Moria (Μόρια Mória). Enclosed by barbed wire and a chain-link fence, the military camp served as a European Union hotspot camp. It burned down and was permanently closed in September 2020. A new closed reception centre will be built in 2021 at Vastria near Nees Kydonies.
 * Kara Tepe Refugee Camp is a camp which has been transformed into a living space for around 700 refugees classified as vulnerable. It will be replaced by a new closed reception centre at Vastria near Nees Kydonies in 2021.
 * Pipka camp or Lesbos Solidarity, once a children's holiday camp, aims to support the most vulnerable refugees who pass through Mytilene: families with children, the disabled, women who are pregnant, and the injured. The camp focuses on humanitarian aid and on providing for the various needs of refugees, including food, medical help, clothing, and psychological support.

Sporting clubs

 * Aiolikos F.C., football club
 * Sappho Lesvou F.C., women's football club

TV
A regional television station operates from the city of Mytilene; Aeolos TV.

Newspapers
The main printed newspapers of the city are Empros, Ta Nea tis Lesvou, and Dimokratis. Online newspapers include Aeolos, Stonisi, Emprosnet, Lesvosnews, Lesvospost, and Kalloninews.

Ancient

 * Alcaeus (6th century BC), Greek poet.
 * Sappho, Ancient Greek Lyric Poet. Plato called her "wise" and "Tenth Muse".
 * Pittacus (c. 640–568 BC), one of the Seven Sages of Greece.
 * Hellanicus (mid-5th century BC), Greek historian.
 * Theophrastus, Ancient Greek philosopher, student of Aristotle.
 * Laomedon of Mytilene (4th BC), general of Alexander the Great
 * Chares (4th century BC), Greek historian and chamberlain to Alexander the Great.
 * Scamon (4th century BC), Greek historian and son of Hellanicus.
 * Praxiphanes (4th century BC), Greek philosopher.
 * Epicurus, Greek philosopher.
 * Aeschines, Greek rhetorician.
 * Eunicus, Greek sculptor and silversmith.
 * Hermarchus (3rd century BC), Greek philosopher.
 * Diophanes (2nd century BC), Greek rhetorician.
 * Lesbonax (1st century BC), Greek sophist and rhetorician.
 * Archytas of Mytilene, Greek musician
 * Crinagoras (70 BC-18 AD), Greek epigrammatist and ambassador, poet of "Palatine Poetry".
 * Theophanes, middle of 1st century BC, Greek statesman, close friend of Pompey the Great.
 * Potamon (1st century AD), Greek rhetorician.

Medieval

 * Santa Thomais (910–1030), nun, philanthropist and healer
 * Christopher of Mytilene (11th century), Greek poet.

Modern

 * Hayreddin Barbarossa ( 1478–1546), Ottoman admiral
 * Oruç Reis (1478–1518), Ottoman bey
 * Saint Parthenios (1600–1657), Patriarch of Constantinople and religious martyr
 * Palaiologos Lemonis, member of Filiki Etaireia
 * Dimitrios Skambas (1992–present), Greek-American financier, youngest Partner at Bannockburn Global Forex in NYC. Parents from Pamfila, Lesvos.
 * Theophilos Hatzimihail (c. 1870–1934), Greek painter
 * P. M. Kourtzis, shipowner, founder of Aegean Steamship Company (1883)
 * Gregorios Bernardakis, philologist
 * Demetrios Bernardakis, playwright
 * Stratis Myrivilis (1892–1969), Greek writer
 * Odysseas Elytis (1911–1996), Greek poet, Nobel Laureate in 1979
 * Argyris Eftaliotis (1849–1923) (née Cleanthis Michailidis), Greek writer
 * Fotis Kontoglou (Aivali/Kydonies, origin from Mytilene) (1895–1965) Greek writer and painter.
 * Georgios Jakobides, painter
 * Hermon di Giovanno (c. 1900–1968), Greek painter
 * Nikos Fermas (1905–1972), Greek actor
 * Irini Mouchou (born 1987), triathlete
 * Giorgos Mouflouzelis (1912–1991), Greek composer of rebetiko
 * Panagiotis Polychronis (1854–1941), Greek artist: photographer, lithographist and painter.
 * Leo Rapitis (1906–1957), Greek singer
 * Konstantinos Kenteris (born 1973), Greek athlete
 * Alexis Panselinos (1903–1984), Greek writer
 * Sophocles Vournazos (1853–1889), Greek philanthropist and founder of Mytilene's academic buildings.
 * Tériade (1889–1983), Greek art critic, patron, and publisher
 * Ahmed Djemal Pasha (1872–1922), Ottoman military leader, perpetrator of the Armenian genocide
 * Tamburi Ali Efendi (1836–1902), Turkish musician
 * Nicholas Kampas (1857–1932), Greek poet
 * Argyris Adalis, architect
 * Nicholas Athanasiadis (1904–1990), Greek theatre writer, literature writer, poet.
 * Ioannis Hatzidaniel (1850–1912), Greek painter and photographer.
 * Solon Lekkas, singer of traditional music from Asia Minor.
 * Giannis Bournellis, comedian, actor.
 * Christos Touramanis, particle physicist
 * Giorgos Vourgoutzis, (born 1991), football player
 * Giorgos Manousos, (born 1987), football player
 * Praxitelis Vouros, (born 1995), football player
 * Michalis Pavlis (born 1989), football player and coach
 * Anastasios Chatzigiovanis, football player

Fictional

 * Lysimachus, in Shakespeare's Pericles, Prince of Tyre

Twin towns – sister cities
Mytilene is twinned with:

 * 🇬🇷 Corfu, Greece
 * Kalamaria, Greece
 * 🇬🇷 Lamia, Greece
 * 🇬🇷 Preveza, Greece
 * 🇨🇾 Paphos, Cyprus
 * 🇺🇸 Portland, Maine, United States
 * 🇯🇵 Setouchi, Okayama Prefecture, Japan (1982)
 * 🇧🇦 Brod, Bosnia and Herzegovina

Consulates
In the past the city hosted consulates from different European countries. Currently hosts consulates from the following countries:
 * 🇫🇷 France

title: Mytilene


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Gennett Records

Gennett Records was an American record company and label in Richmond, Indiana, United States, which flourished in the 1920s and produced the Gennett, Starr, Champion, Superior, and Van Speaking labels. The company also produced some Supertone, Silvertone, and Challenge records under contract. The firm also pressed, under contract, records for record labels such as Autograph, Rainbow, Hitch, Our Song, and Vaughn; Gennett also pressed records for the Ku Klux Klan (KKK). Gennett produced some of the earliest recordings by Louis Armstrong, King Oliver, Bix Beiderbecke, and Hoagy Carmichael. Its roster also included Jelly Roll Morton, Blind Lemon Jefferson, Charley Patton, and Gene Autry.

History
Gennett Records was founded in Richmond, Indiana, by the Starr Piano Company in 1917. By the late 1930s, the label had produced more than 16,000 masters. The company had produced early recordings under the green or blue Starr Records label as early as 1915. The new Gennett label was named after Harry, Fred, and Clarence Gennett, brothers and joint managers, and was an attempt to distinguish the label from its parent company and widen distribution beyond Starr piano stores. Early record pressings were outsourced but by October 1917, Starr Valley - home to the Starr Piano manufacturing campus along the Whitewater River - had a six-story phonograph and manufacturing and record-pressing facility. The early issues were vertically cut in the phonograph record grooves, using the hill-and-dale method of a U-shaped groove and sapphire ball stylus, but they switched to the lateral cut method in April 1919. Gennett Records rarely paid artists upfront. Some were paid a flat fee, from $15-50 per session, while Black artists received even less. Most artists signed royalty contracts that promised one penny for each copy or side sold.

Gennett first set up a recording studio in Manhattan, New York City. Throughout the 1920s, the Manhattan studio saw artists such as Bailey's Lucky Seven, the Original Memphis Five under the pseudonym Ladd's Black Aces, and in November 1924, Louis Armstrong and the Red Onion Jazz Babies. In 1921, the label set up a second studio on the grounds of the piano factory in Richmond under the supervision of Ezra C.A. Wickemeyer, who would manage the studio from August 1921 to mid-1927. The bulk of the labels productions came out of the Richmond studio, which was 125 ft long and 30 ft wide with a control room separated by a double pane of glass. For sound proofing, a Mohawk rug was placed on the floor and drapes and towels were hung on the wall. Gennett was one of the few companies to have a recording facility outside of New York, a move which allowed the label to capture Midwestern and Southern artists. Their locality also led to their recordings being appealing to Black individuals and other rural peoples who were largely neglected by the leading New York labels. Some call the Richmond studio the "cradle of recorded jazz."

Gennett recorded early jazz musicians Jelly Roll Morton, Bix Beiderbecke, The New Orleans Rhythm Kings, King Oliver's band with Louis Armstrong, Lois Deppe's Serenaders with Earl Hines, Hoagy Carmichael, Duke Ellington, The Red Onion Jazz Babies, The State Street Ramblers, Zack Whyte and his Chocolate Beau Brummels, Alphonse Trent and his Orchestra and many others. Many of these jazz artists, such as Morton, the Rhythm Kings, and Oliver's band were popular at the Lincoln Gardens and the Friar's Inn nightclubs and had been sent by train to rural Richmond by Chicago, Illinois Starr Piano store manager and talent scout Fred Wiggins. Gennett notably was among the first to record people of color and racially integrated sessions, despite over twenty percent of Wayne County's white male population being members of the Ku Klux Klan. Other estimates suggest forty to fifty percent of non-Catholic white men were members of the Richmond klavern.

Throughout the 1920s, Gennett pressed vanity records for the Ku Klux Klan with red labels and gold KKK lettering, often listing performers such as the "100 percent Americans." Klan members politicized hymns with new lyrics, such as "Onward Christian Klansman" for "Onward Christian Soldiers" as well as custom songs such as "Daddy Swiped Our Last Clean Sheet and Joined the Ku Klux Klan." These private pressings never appeared in Gennett catalogs and were shipped directly to Klan headquarters in Indianapolis after the Klan paid for the records. Some of D.C. Stephenson's speeches were recorded by the label. Ironically, Richmond had a large gathering of Ku Klux Klan members in Glen Miller Park followed by a parade on October 5, 1923, the same day King Oliver's Creole Jazz Band, with Louis Armstrong, recorded a second series of discs at the Richmond studio. Approximately 30,000 people gathered with Richmond residents to view over 6,000 Klan members participate in a parade. Although the Gennett family was not involved in the Richmond klavern, historian Leonard Moore estimates one of every three native-born white Protestant male in Richmond was a member during this time.

Gennett also recorded early blues and gospel music artists such as Thomas A. Dorsey, Sam Collins, Jaybird Coleman, as well as early hillbilly or country music performers such as Vernon Dalhart, Bradley Kincaid, Ernest Stoneman, Fiddlin' Doc Roberts, and Gene Autry. Blues artists from Chicago, such as Georgia Tom Dorsey, Big Bill Broonzy, and Scrapper Blackwell, recorded in Richmond. The label preserved several rare varieties of traditional Kentucky music thanks to the work of talent scouts Dennis Taylor and, eventually, one of Taylor's recruits the Fiddlin' Doc Roberts, recording more Kentucky musicians than any other state. Taylor brought hundreds of Kentucky musicians to Richmond between 1925 and 1931, including Asa Martin, Marion Underwood, and Charlie Taylor.

Many early religious recordings were made by Homer Rodeheaver, early shape note singers and others. Classical ensembles around the Midwest, such as the Cincinnati Symphony Orchestra, traveled to Richmond to record. Gennett also recorded groups such as Gonzalez's Mexican Band, the Hawaiian Guitars, the National Marimba Orchestra, and the Italian Degli Arditi Orchestra. Temporary recording studios were sometimes set up in various Starr Piano Company stores or other buildings. Their downtown Cincinnati, Ohio store recorded West Virginian singer David Miller for a time. The Birmingham, Alabama store, in July and August 1927 under the direction of recording engineer Gordon Soule, which attracted many Southern country blues artists such as Jaybird Coleman and Johnny Watson under the name Daddy Stove Pipe. The Birmingham studio also recorded William Harris, an early Mississippi Delta blues player. From September to November 1927, portable sound equipment was set up in the Hotel Lowry in St. Paul, Minnesota where primarily Swedish, German, and Polish folk music was recorded. Temporary studios were set up in Chicago from November-December 1927 and February-April 1928.

By the late 1920s, Gennett was pressing records for more than 25 labels worldwide, including budget disks for the Sears catalog. In 1926, Fred Gennett created Champion Records as a budget label for tunes previously released on Gennett. Many of the recording artists used pseudonyms, such as the Seven Champions for Bailey's Lucky Seven, Skillet Dick and His Frying Pans for Syd Valentine and His Patent Leather Kids - a Black Indiana jazz trio, and the Hill Top Inn Orchestra for Guy Lombardo and His Royal Canadians. Some Champion artists were not informed that their recordings were reissued under pseudonyms.

Gennett issued a few early electrically recorded masters recorded in the Autograph studios in Chicago in 1925. These recordings were exceptionally crude, and like many other Autograph issues can be easily mistaken for acoustic masters. Gennett began serious electrical recording in March 1926, using a process licensed from General Electric which was found to be unsatisfactory. Although the quality of the recordings taken by the General Electric process was quite good, there were many customer complaints about poor wear characteristics of the electric process records. The composition of the Gennett biscuit (record material) was of insufficient hardness to withstand the increased wear that resulted when the new recordings with their greatly increased frequency range were played on obsolete phonographs with mica diaphragm reproducers. The company discontinued recording by this process in August 1926, and did not return to electric recording until February 1927, after signing a new agreement to license the RCA Photophone recording process. The company also introduced an improved record biscuit which was adequate to the demands imposed by the electric recording process. The improved records were identified by a newly designed black label touting the "New Electrobeam" process.

Recordings were not limited to music. In 1923, orator and statesman William Jennings Bryan traveled to Richmond to record portions of his 1896 Cross of Gold speech, which was released in 1924. In the 1930s, Harry Gennett, Jr. became involved in the recording business and roamed the country in the Gennett recording truck producing sound effects. The Gennett catalog of sound recordsings would be sold by mail to radio stations and filmmakers.

The label was hit severely by the Great Depression in 1930. It cut back on record recording and production and only maintained the budget Champion label until halting activities altogether in 1934. Throughout the 1930s, Fred Wiggins sold thousands of metal discs, which would be worth millions after Gennett's rise to fame, for scrap money, likely to make payroll for Starr Piano employess. At this time, the only product Gennett Records produced under its own name was a series of recorded sound effects for use by radio stations. In 1935, the Starr Piano Company sold some Gennett masters, and the Gennett and Champion trademarks to Decca Records. Jack Kapp of Decca was primarily interested in jazz, blues and old time music items in the Gennett catalog which he thought would add depth to the selections offered by the newly organized Decca. Kapp attempted to revive the Gennett and Champion labels between 1935 and 1937 specializing in bargain pressings of race and old-time music with but little success.

The Starr record plant soldiered on under the supervision of Harry Gennett through the remainder of the decade by offering contract pressing services. For a time the Starr Piano Company was the principal manufacturer of Decca records, but much of this business dried up after Decca purchased its own pressing plant in 1938 (the Newaygo, Michigan, plant that formerly had pressed Brunswick and Vocalion records). In the years remaining before World War II, Gennett did contract pressing for New York-based jazz and folk music labels, including Joe Davis, who briefly produced records on Gennett, Beacon, and Joe Davis labels that were pressed in Starr Valley.

With the coming of the Second World War, the War Production Board in March 1942 declared shellac a rationed commodity, limiting record manufacturers to 70% of their 1939 shellac usage. Newly organized record labels were forced to purchase their shellac from existing companies. Joe Davis purchased the Gennett shellac allocation, some of which he used for his own labels, and some of which he sold to the newly formed Capitol Records. Harry Gennett intended to use the funds from the sale of his shellac ration to modernize this pressing plant after Victory, but there is no indication that he did so. Gennett sold decreasing numbers of special purpose records (mostly sound effects, skating rink, and church tower chimes) until 1947 or 1948, and the business then faded away.

Brunswick Records acquired the old Gennett pressing plant for Decca. After Decca opened a new pressing plant in Pinckneyville, Illinois, in 1956, the old Gennett plant in Richmond, Indiana, was sold to Mercury Records in 1958. Mercury operated the historic plant until 1969 when it moved to a nearby modern plant later operated by Cinram.

Gennett Walk of Fame
In September 2007, the Starr-Gennett Foundation began to honor the most important Gennett artists on a Walk of Fame near the site of Gennett's Richmond, Indiana, recording studio.

The Gennett Walk of Fame is located along South 1st Street in Richmond at the site of the Starr Piano Company and embedded in the Whitewater Gorge Trail, which connects to the longer Cardinal Greenway Trail. Both trails are part of the American Discovery Trail, the only coast-to-coast, non-motorized recreational trail.

The Foundation convened its National Advisory Board in January, 2006, to choose the first 10 inductees. The inductees are selected from: classic jazz, old-time country, blues, gospel (African-American and Southern), American popular song, ethnic, historic/spoken, and classical, giving preference to the first five categories.

The consensus selection for the first inductee in the Gennett Walk of Fame was Louis Armstrong. The first ten inductees were:
 * Louis Armstrong
 * Bix Beiderbecke
 * Jelly Roll Morton
 * Hoagy Carmichael
 * Gene Autry
 * Vernon Dalhart
 * Big Bill Broonzy
 * Georgia Tom
 * King Oliver
 * Lawrence Welk

A second set of ten nominees was inducted in 2008:
 * Homer Rodeheaver
 * Fats Waller
 * Duke Ellington
 * Uncle Dave Macon
 * Coleman Hawkins
 * Charley Patton
 * Sidney Bechet
 * Blind Lemon Jefferson
 * Fletcher Henderson
 * Guy Lombardo

2009 Inductees:
 * Artie Shaw
 * Wendell Hall
 * Bradley Kincaid
 * Ernest Stoneman and Hattie Frost Stoneman
 * New Orleans Rhythm Kings

2010 Inductees:
 * Alberta Hunter
 * Lonnie Johnson
 * Pace Jubilee Singers

2011 Inductees:
 * Roosevelt Sykes
 * Bailey's Lucky Seven

2012 Inductees:
 * Scrapper Blackwell
 * Jelly Roll Morton

2013 Inductee:
 * William Jennings Bryan

2014 Inductee:
 * Doc Roberts & Asa Martin

2016 Inductee:
 * Jimmy Durante

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/

title: Gennett Records


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Period 4 element

A period 4 element is one of the chemical elements in the fourth row (or period) of the periodic table of the chemical elements. The periodic table is laid out in rows to illustrate recurring (periodic) trends in the chemical behaviour of the elements as their atomic number increases: a new row is begun when chemical behaviour begins to repeat, meaning that elements with similar behaviour fall into the same vertical columns. The fourth period contains 18 elements beginning with potassium and ending with krypton – one element for each of the eighteen groups. It sees the first appearance of d-block (which includes transition metals) in the table.

Properties
All 4th-period elements are stable, and many are extremely common in the Earth's crust and/or core; it is the last period with no unstable elements. Many transition metals in the period are very strong, and therefore common in industry, especially iron. Some are toxic, with all known vanadium compounds toxic, arsenic one of the most well-known poisons, and bromine a toxic liquid. Conversely, many elements are essential to human survival, such as calcium, the main component in bones.

Atomic structure
Progressing towards increase of atomic number, the Aufbau principle causes elements of the period to put electrons onto 4s, 3d, and 4p subshells, in that order. However, there are exceptions, such as chromium. The first twelve elements—K, Ca, and transition metals—have from 1 to 12 valence electrons respectively, which are placed on 4s and 3d.

Twelve electrons over the electron configuration of argon reach the configuration of zinc, namely 3d10 4s2. After this element, the filled 3d subshell effectively withdraws from chemistry and the subsequent trend looks much like trends in the periods 2 and 3. The p-block elements of period 4 have their valence shell composed of 4s and 4p subshells of the fourth ($n = 4$) shell and obey the octet rule.

For quantum chemistry namely this period sees transition from the simplified electron shell paradigm to research of many differently-shaped subshells. The relative disposition of their energy levels is governed by the interplay of various physical effects. The period's s-block metals put their differentiating electrons onto 4s despite having vacancies among nominally lower $n = 3$ states – a phenomenon unseen in lighter elements. Contrariwise, the six elements from gallium to krypton are the heaviest where all electron shells below the valence shell are filled completely. This is no longer possible in further periods due to the existence of f-subshells starting from $n = 4$.

List of elements

 * {| class="wikitable sortable"

! colspan="3" | Chemical element ! Block ! Electron configuration ! ! ! ! !
 * - bgcolor=""
 * 19 || K || Potassium || s-block || [Ar] 4s1
 * - bgcolor=""
 * 20 || Ca || Calcium || s-block || [Ar] 4s2
 * - bgcolor=""
 * 21 || Sc || Scandium || d-block || [Ar] 3d1 4s2
 * - bgcolor=""
 * 22 || Ti || Titanium || d-block || [Ar] 3d2 4s2
 * - bgcolor=""
 * 23 || V || Vanadium || d-block || [Ar] 3d3 4s2
 * - bgcolor=""
 * 24 || Cr || Chromium || d-block || [Ar] 3d5 4s1 (*)
 * - bgcolor=""
 * 25 || Mn || Manganese || d-block || [Ar] 3d5 4s2
 * - bgcolor=""
 * 26 || Fe || Iron || d-block || [Ar] 3d6 4s2
 * - bgcolor=""
 * 27 || Co || Cobalt || d-block || [Ar] 3d7 4s2
 * - bgcolor=""
 * 28 || Ni || Nickel || d-block || [Ar] 3d8 4s2
 * - bgcolor=""
 * 29 || Cu || Copper || d-block || [Ar] 3d10 4s1 (*)
 * - bgcolor=""
 * 30 || Zn || Zinc || d-block || [Ar] 3d10 4s2
 * - bgcolor=""
 * 31 || Ga || Gallium || p-block || [Ar] 3d10 4s2 4p1
 * - bgcolor=""
 * 32 || Ge || Germanium || p-block || [Ar] 3d10 4s2 4p2
 * - bgcolor=""
 * 33 || As || Arsenic || p-block || [Ar] 3d10 4s2 4p3
 * - bgcolor=""
 * 34 || Se || Selenium || p-block || [Ar] 3d10 4s2 4p4
 * - bgcolor=""
 * 35 || Br || Bromine || p-block || [Ar] 3d10 4s2 4p5
 * - bgcolor=""
 * 36 || Kr || Krypton || p-block || [Ar] 3d10 4s2 4p6
 * }

(*) Exception to the Madelung rule

Potassium
Potassium (K) is an alkali metal, underneath sodium and above rubidium, and the first element of period 4. One of the most reactive chemical elements, it is usually found only in compounds. It is a silvery metal that tarnishes rapidly when exposed to the oxygen in air, which oxidizes it. It is soft enough to be cut with a knife and the second least-dense element. Potassium has a relatively low melting point; it will melt under a small open flame. It also is less dense than water, and can, in principle, float (although it will react with any water it is exposed to).

Calcium
Calcium (Ca) is the second element in the period. An alkali earth metal, native calcium is almost never found in nature, because it reacts with water. It has one of the most widely-known biological roles in all animals and some plants, making up structural elements such as bones and teeth. It also has applications in cells, such as signals for cellular processeses. It is regarded as the most abundant mineral in the human body.

Scandium
Scandium (Sc) is the third element in the period, and is the first transition metal in the periodic table. Scandium is quite common in nature, but difficult to isolate because its chemistry mirrors that of the other rare earth compounds quite closely. Scandium has very few commercial applications, the major exception being aluminium alloys.

Titanium
Titanium (Ti) is an element in group 4. Titanium is both one of the least dense metals and one of the strongest and most corrosion-resistant. As such, it has many applications, especially in alloys with other elements, such as iron. It is commonly used in airplanes, golf clubs, and other objects that must be strong, but lightweight.

Vanadium
Vanadium (V) is an element in group 5. Vanadium is never found in pure form in nature, but is commonly found in compounds. Vanadium is similar to titanium in many ways, such as being very corrosion-resistant, however, unlike titanium, it oxidizes in air even at room temperature. All vanadium compounds have at least some level of toxicity, with some of them being extremely toxic.

Chromium
Chromium (Cr) is an element in group 6. Chromium is, like titanium and vanadium before it, extremely resistant to corrosion, and is indeed one of the main components of stainless steel. Chromium also has many colorful compounds, and as such is very commonly used in pigments, such as chrome green.

Manganese
Manganese (Mn) is an element in group 7. Manganese is often found in combination with iron. Manganese, like chromium before it, is an important component in stainless steel, preventing the iron from rusting. Manganese is also often used in pigments, again like chromium. Manganese is also poisonous; if enough is inhaled, it can cause irreversible neurological damage.

Iron
Iron (Fe) is an element in group 8. Iron is the most common on Earth among elements of the period, and probably the most well-known of them. It is the principal component of steel. Iron-56 has the lowest energy density of any isotope of any element, meaning that it is the most massive element that can be produced in supergiant stars. Iron also has some applications in the human body; hemoglobin is partly iron.

Cobalt
Cobalt (Co) is an element in group 9. Cobalt is commonly used in pigments, as many compounds of cobalt are blue in color. Cobalt is also a core component of many magnetic and high-strength alloys. The only stable isotope, cobalt-59, is an important component of vitamin B-12, while cobalt-60 is a component of nuclear fallout and can be dangerous in large enough quantities due to its radioactivity.

Nickel
Nickel (Ni) is an element in group 10. Nickel is rare in the Earth's crust, mainly due to the fact that it reacts with oxygen in the air, with most of the nickel on Earth coming from nickel iron meteorites. However, nickel is very abundant in the Earth's core; along with iron it is one of the two main components. Nickel is an important component of stainless steel, and in many superalloys.

Copper
Copper (Cu) is an element in group 11. Copper is one of the few metals that is not white or gray in color, the only others being gold, osmium and caesium. Copper has been used by humans for thousands of years to provide a reddish tint to many objects, and is even an essential nutrient to humans, although too much is poisonous. Copper is also commonly used as a wood preservative or fungicides.

Zinc
Zinc (Zn) is an element in group 12. Zinc is one of the main components of brass, being used since the 10th century BCE. Zinc is also incredibly important to humans; almost 2 billion people in the world suffer from zinc deficiency. However, too much zinc can cause copper deficiency. Zinc is often used in batteries, aptly named carbon-zinc batteries, and is important in many platings, as zinc is very corrosion resistant.

Gallium
Gallium (Ga) is an element in group 13, under aluminium. Gallium is noteworthy because it has a melting point at about 303 kelvins, right around room temperature. For example, it will be solid on a typical spring day, but will be liquid on a hot summer day. Gallium is an important component in the alloy galinstan, along with tin. Gallium can also be found in semiconductors.

Germanium
Germanium (Ge) is an element in group 14. Germanium, like silicon above it, is an important semiconductor and is commonly used in diodes and transistors, often in combination with arsenic. Germanium is fairly rare on Earth, leading to its comparatively late discovery. Germanium, in compounds, can sometimes irritate the eyes, skin, or lungs.

Arsenic
Arsenic (As) is an element in group 15, the pnictogens. Arsenic, as mentioned above, is often used in semiconductors in alloys with germanium. Arsenic, in pure form and some alloys, is incredibly poisonous to all multicellular life, and as such is a common component in pesticides. Arsenic was also used in some pigments before its toxicity was discovered.

Selenium
Selenium (Se) is an element in group 16, the chalcogens. Selenium is the first nonmetal in period 4, with properties similar to sulfur. Selenium is quite rare in pure form in nature, mostly being found in minerals such as pyrite, and even then it is quite rare. Selenium is necessary for humans in trace amounts, but is toxic in larger quantities. Selenium is red in monomolar structure but metallic gray in its crystalline structure.

Bromine
Bromine (Br) is an element in group 17 (halogen). It does not exist in elemental form in nature. Bromine is barely liquid at room temperature, boiling at about 330 kelvins. Bromine is also quite toxic and corrosive, but bromide ions, which are relatively inert, can be found in halite, or table salt. Bromine is often used as a fire retardant because many compounds can be made to release free bromine atoms.

Krypton
Krypton (Kr) is a noble gas, placed under argon and over xenon. Being a noble gas, krypton rarely interacts with itself or other elements; although compounds have been detected, they are all unstable and decay rapidly, and as such, krypton is often used in fluorescent lights. Krypton, like most noble gases, is also used in lighting because of its many spectral lines and the aforementioned reasons.

Biological role
Many period 4 elements find roles in controlling protein function as secondary messengers, structural components, or enzyme cofactors. A gradient of potassium is used by cells to maintain a membrane potential which enables neurotransmitter firing and facilitated diffusion among other processes. Calcium is a common signaling molecule for proteins such as calmodulin and plays a critical role in triggering skeletal muscle contraction in vertebrates. Selenium is a component of the noncanonical amino acid, selenocysteine; proteins which contain selenocysteine are known as selenoproteins. Manganese enzymes are utilized by both eukaryotes and prokaryotes, and may play a role in the virulence of some pathogenic bacteria. Vanabins, also known as vanadium-associated proteins, are found in the blood cells of some species of sea squirts. The role of these proteins is disputed, although there is some speculation that they function as oxygen carriers. Zinc ions are used to stabilize the zinc finger milieu of many DNA-binding proteins.

Period 4 elements can also be found complexed with organic small molecules to form cofactors. The most famous example of this is heme: an iron-containing porphyrin compound responsible for the oxygen-carrying function of myoglobin and hemoglobin as well as the catalytic activity of cytochrome enzymes. Hemocyanin replaces hemoglobin as the oxygen carrier of choice in the blood of certain invertebrates, including horseshoe crabs, tarantulas, and octopuses. Vitamin B12 represents one of the few biochemical applications for cobalt.

title: Period 4 element


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Talk:Literature of Wales

If anyone else wants to contribute to this article, please go ahead!

No, you do it! You are the expert! Looking forward to reading this article. --KF 22:25 Feb 10, 2003 (UTC)

English Version
Is a complete English version of 'Yr Arwr' available on the web?

Disambiguate
I propose a 'move' to Literature in Wales - it makes more sense and we are dealing with writers of Welsh and English. The current "Welsh Literature" could easily be seen as Welsh-language literature. --Matt Lewis (talk) 14:51, 25 May 2008 (UTC)

We could merge in Anglo-Welsh literature, while redirecting that page. I find it confusing as it is - the first line in particular suggests it can be both Welsh and English - clearly the content just covers Welsh. Perhaps Welsh literature could be a disambiguation page to Welsh-language literature and Anglo-Welsh literature? --Matt Lewis (talk) 19:47, 25 May 2008 (UTC)

 * That seems reasonable to me. garik (talk) 16:17, 30 June 2008 (UTC)
 * I'd support that proposal. Ghmyrtle (talk) 23:54, 15 November 2008 (UTC)

I suggest that further discussion be coordinated here. Ghmyrtle (talk) 09:42, 16 November 2008 (UTC)

 * I've now created this page as a disambiguation page, per the discussions here. However, this page does need some expansion now, in order to give a brief overview and show the relationship between the literary traditions in the two languages (and other languages, such as Latin, as appropriate).  Over to others - I'm not qualified or sufficiently engaged to do that.  Ghmyrtle (talk) 19:06, 6 December 2008 (UTC)

title: Talk:Literature of Wales


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Period 6 element

A period 6 element is one of the chemical elements in the sixth row (or period) of the periodic table of the chemical elements, including the lanthanides. The periodic table is laid out in rows to illustrate recurring (periodic) trends in the chemical behaviour of the elements as their atomic number increases: a new row is begun when chemical behaviour begins to repeat, meaning that elements with similar behaviour fall into the same vertical columns. The sixth period contains 32 elements, tied for the most with period 7, beginning with caesium and ending with radon. Lead is currently the last stable element; all subsequent elements are radioactive. For bismuth, however, its only primordial isotope, 209Bi, has a half-life of more than 1019 years, over a billion times longer than the current age of the universe. As a rule, period 6 elements fill their 6s shells first, then their 4f, 5d, and 6p shells, in that order; however, there are exceptions, such as gold.

Properties
This period contains the lanthanides, also known as the rare earths. Many lanthanides are known for their magnetic properties, such as neodymium. Many period 6 transition metals are very valuable, such as gold, however many period 6 other metals are incredibly toxic, such as thallium. Period 6 contains the last stable element, lead. All subsequent elements in the periodic table are radioactive. After bismuth, which has a half-life or more than 1019 years, polonium, astatine, and radon are some of the shortest-lived and rarest elements known; less than a gram of astatine is estimated to exist on earth at any given time.

Atomic characteristics

 * {| class="wikitable sortable"

! colspan="3" | '''Chemical element ! Block ! Electron configuration
 * - bgcolor=""
 * 55 || Cs || Caesium || s-block || [Xe] 6s1
 * - bgcolor=""
 * 56 || Ba || Barium || s-block || [Xe] 6s2
 * - bgcolor=""
 * 57 || La || Lanthanum || f-block || [Xe] 5d1 6s2
 * - bgcolor=""
 * 58 || Ce || Cerium || f-block || [Xe] 4f1 5d1 6s2
 * - bgcolor=""
 * 59 || Pr || Praseodymium || f-block || [Xe] 4f3 6s2
 * - bgcolor=""
 * 60 || Nd || Neodymium || f-block || [Xe] 4f4 6s2
 * - bgcolor=""
 * 61 || Pm || Promethium || f-block || [Xe] 4f5 6s2
 * - bgcolor=""
 * 62 || Sm || Samarium || f-block || [Xe] 4f6 6s2
 * - bgcolor=""
 * 63 || Eu || Europium || f-block || [Xe] 4f7 6s2
 * - bgcolor=""
 * 64 || Gd || Gadolinium || f-block || [Xe] 4f7 5d1 6s2
 * - bgcolor=""
 * 65 || Tb || Terbium || f-block || [Xe] 4f9 6s2
 * - bgcolor=""
 * 66 || Dy || Dysprosium || f-block || [Xe] 4f10 6s2
 * - bgcolor=""
 * 67 || Ho || Holmium || f-block || [Xe] 4f11 6s2
 * - bgcolor=""
 * 68 || Er || Erbium || f-block || [Xe] 4f12 6s2
 * - bgcolor=""
 * 69 || Tm || Thulium || f-block || [Xe] 4f13 6s2
 * - bgcolor=""
 * 70 || Yb || Ytterbium || f-block || [Xe] 4f14 6s2
 * - bgcolor=""
 * 71 || Lu || Lutetium || d-block  || [Xe] 4f14 5d1 6s2
 * - bgcolor=""
 * 72 || Hf || Hafnium || d-block || [Xe] 4f14 5d2 6s2
 * - bgcolor=""
 * 73 || Ta || Tantalum || d-block || [Xe] 4f14 5d3 6s2
 * - bgcolor=""
 * 74 || W || Tungsten || d-block || [Xe] 4f14 5d4 6s2
 * - bgcolor=""
 * 75 || Re || Rhenium || d-block || [Xe] 4f14 5d5 6s2
 * - bgcolor=""
 * 76 || Os || Osmium || d-block || [Xe] 4f14 5d6 6s2
 * - bgcolor=""
 * 77 || Ir || Iridium || d-block || [Xe] 4f14 5d7 6s2
 * - bgcolor=""
 * 78 || Pt || Platinum || d-block || [Xe] 4f14 5d9 6s1
 * - bgcolor=""
 * 79 || Au || Gold || d-block || [Xe] 4f14 5d10 6s1
 * - bgcolor=""
 * 80 || Hg || Mercury || d-block || [Xe] 4f14 5d10 6s2
 * - bgcolor=""
 * 81 || Tl || Thallium || p-block || [Xe] 4f14 5d10 6s2 6p1
 * - bgcolor=""
 * 82 || Pb || Lead || p-block || [Xe] 4f14 5d10 6s2 6p2
 * - bgcolor=""
 * 83 || Bi || Bismuth || p-block || [Xe] 4f14 5d10 6s2 6p3
 * - bgcolor=""
 * 84 || Po || Polonium || p-block || [Xe] 4f14 5d10 6s2 6p4
 * - bgcolor=""
 * 85 || At || Astatine || p-block || [Xe] 4f14 5d10 6s2 6p5
 * - bgcolor=""
 * 86 || Rn || Radon || p-block || [Xe] 4f14 5d10 6s2 6p6
 * }

 * In many periodic tables, the f-block is erroneously shifted one element to the right, so that lanthanum and actinium become d-block elements, and Ce–Lu and Th–Lr form the f-block, tearing the d-block into two very uneven portions. This is a holdover from early erroneous measurements of electron configurations. Lev Landau and Evgeny Lifshitz pointed out in 1948 that lutetium is not an f-block element, and since then physical, chemical, and electronic evidence has overwhelmingly supported that the f-block contains the elements La–Yb and Ac–No, as shown here and as supported by International Union of Pure and Applied Chemistry reports dating from 1988 and 2021.
 * An exception to the Madelung rule.

Caesium
Caesium or cesium is the chemical element with the symbol Cs and atomic number 55. It is a soft, silvery-gold alkali metal with a melting point of 28 °C (82 °F), which makes it one of only five elemental metals that are liquid at (or near) room temperature. Caesium is an alkali metal and has physical and chemical properties similar to those of rubidium and potassium. The metal is extremely reactive and pyrophoric, reacting with water even at−116 °C (−177 °F). It is the least electronegative element having a stable isotope, caesium-133. Caesium is mined mostly from pollucite, while the radioisotopes, especially caesium-137, a fission product, are extracted from waste produced by nuclear reactors.

Two German chemists, Robert Bunsen and Gustav Kirchhoff, discovered caesium in 1860 by the newly developed method of flame spectroscopy. The first small-scale applications for caesium have been as a "getter" in vacuum tubes and in photoelectric cells. In 1967, a specific frequency from the emission spectrum of caesium-133 was chosen to be used in the definition of the second by the International System of Units. Since then, caesium has been widely used in atomic clocks.

Since the 1990s, the largest application of the element has been as caesium formate for drilling fluids. It has a range of applications in the production of electricity, in electronics, and in chemistry. The radioactive isotope caesium-137 has a half-life of about 30 years and is used in medical applications, industrial gauges, and hydrology. Although the element is only mildly toxic, it is a hazardous material as a metal and its radioisotopes present a high health risk in case of radioactivity releases.

Barium
Barium is a chemical element with the symbol Ba and atomic number 56. It is the fifth element in Group 2, a soft silvery metallic alkaline earth metal. Barium is never found in nature in its pure form due to its reactivity with air. Its oxide is historically known as baryta but it reacts with water and carbon dioxide and is not found as a mineral. The most common naturally occurring minerals are the very insoluble barium sulfate, BaSO4 (barite), and barium carbonate, BaCO3(witherite). Barium's name originates from Greek barys (βαρύς), meaning "heavy", describing the high density of some common barium-containing ores.

Barium has few industrial applications, but the metal has been historically used to scavenge air in vacuum tubes. Barium compounds impart a green color to flames and have been used in fireworks. Barium sulfate is used for its density, insolubility, and X-ray opacity. It is used as an insoluble heavy additive to oil well drilling mud, and in purer form, as an X-ray radiocontrast agent for imaging the human gastrointestinal tract. Soluble barium compounds are poisonous due to release of the soluble barium ion, and have been used as rodenticides. New uses for barium continue to be sought. It is a component of some "high temperature" YBCOsuperconductors, and electroceramics.

f-block elements (lanthanides)
The lanthanide or lanthanoid (IUPAC nomenclature) series comprises the fifteen metallic chemical elements with atomic numbers 57 through 71, from lanthanum through lutetium. These fifteen elements, along with the chemically similar elements scandium and yttrium, are often collectively known as the rare-earth elements.

The informal chemical symbol Ln is used in general discussions of lanthanide chemistry. All but one of the lanthanides are f-block elements, corresponding to the filling of the 4f electron shell; lanthanum, a d-block element, is also generally considered to be a lanthanide due to its chemical similarities with the other fourteen. All lanthanide elements form trivalent cations, Ln3+, whose chemistry is largely determined by the ionic radius, which decreases steadily from lanthanum to lutetium.

 * Between initial [Xe] and final 6s2 electronic shells

The lanthanide elements are the group of elements with atomic number increasing from 57 (lanthanum) to 71 (lutetium). They are termed lanthanide because the lighter elements in the series are chemically similar to lanthanum. Strictly speaking, both lanthanum and lutetium have been labeled as group 3 elements, because they both have a single valence electron in the d shell. However, both elements are often included in any general discussion of the chemistry of the lanthanide elements.

In presentations of the periodic table, the lanthanides and the actinides are customarily shown as two additional rows below the main body of the table, with placeholders or else a selected single element of each series (either lanthanum or lutetium, and either actinium or lawrencium, respectively) shown in a single cell of the main table, between barium and hafnium, and radium and rutherfordium, respectively. This convention is entirely a matter of aesthetics and formatting practicality; a rarely used wide-formatted periodic table inserts the lanthanide and actinide series in their proper places, as parts of the table's sixth and seventh rows (periods).

Lutetium
Lutetium is a chemical element with the symbol Lu and atomic number 71. It is the last element in the lanthanide series, which, along with the lanthanide contraction, explains several important properties of lutetium, such as it having the highest hardness or density among lanthanides. Unlike other lanthanides, which lie in the f-block of the periodic table, this element lies in the d-block; however, lanthanum is sometimes placed on the d-block lanthanide position. Chemically, lutetium is a typical lanthanide: its only common oxidation state is +3, seen in its oxide, halides and other compounds. In an aqueous solution, like compounds of other late lanthanides, soluble lutetium compounds form a complex with nine water molecules.

Lutetium was independently discovered in 1907 by French scientist Georges Urbain, Austrian mineralogist Baron Carl Auer von Welsbach, and American chemist Charles James. All of these men found lutetium as an impurity in the mineral ytterbia, which was previously thought to consist entirely of ytterbium. The dispute on the priority of the discovery occurred shortly after, with Urbain and von Welsbach accusing each other of publishing results influenced by the published research of the other; the naming honor went to Urbain as he published his results earlier. He chose the name lutecium for the new element but in 1949 the spelling of element 71 was changed to lutetium. In 1909, the priority was finally granted to Urbain and his names were adopted as official ones; however, the name cassiopeium (or later cassiopium) for element 71 proposed by von Welsbach was used by many German scientists until the 1950s. Like other lanthanides, lutetium is one of the elements that traditionally were included in the classification "rare earths."

Lutetium is rare and expensive; consequently, it has few specific uses. For example, a radioactive isotope lutetium-176 is used in nuclear technology to determine the age of meteorites. Lutetium usually occurs in association with the element yttrium and is sometimes used in metal alloys and as a catalyst in various chemical reactions. 177Lu-DOTA-TATE is used for radionuclide therapy (see Nuclear medicine) on neuroendocrine tumours.

Hafnium
Hafnium is a chemical element with the symbol Hf and atomic number 72. A lustrous, silvery gray, tetravalent transition metal, hafnium chemically resembles zirconium and is found in zirconium minerals. Its existence was predicted by Dmitri Mendeleev in 1869. Hafnium was the penultimate stable isotope element to be discovered (rhenium was identified two years later). Hafnium is named for Hafnia, the Latin name for "Copenhagen", where it was discovered.

Hafnium is used in filaments and electrodes. Some semiconductor fabrication processes use its oxide for integrated circuits at 45 nm and smaller feature lengths. Some superalloys used for special applications contain hafnium in combination with niobium, titanium, or tungsten.

Hafnium's large neutron capture cross-section makes it a good material for neutron absorption in control rods in nuclear power plants, but at the same time requires that it be removed from the neutron-transparent corrosion-resistant zirconium alloys used in nuclear reactors.

Tantalum
Tantalum is a chemical element with the symbol Ta and atomic number 73. Previously known as tantalium, the name comes from Tantalus, a character from Greek mythology. Tantalum is a rare, hard, blue-gray, lustrous transition metal that is highly corrosion resistant. It is part of the refractory metals group, which are widely used as minor component in alloys. The chemical inertness of tantalum makes it a valuable substance for laboratory equipment and a substitute for platinum, but its main use today is in tantalum capacitors in electronic equipment such as mobile phones, DVD players, video game systems and computers. Tantalum, always together with the chemically similar niobium, occurs in the minerals tantalite, columbite and coltan (a mix of columbite and tantalite).

Tungsten
Tungsten, also known as wolfram, is a chemical element with the chemical symbol W and atomic number 74. The word tungsten comes from the Swedish language tung sten directly translatable to heavy stone, though the name is volfram in Swedish to distinguish it from Scheelite, in Swedish alternatively named tungsten.

A hard, rare metal under standard conditions when uncombined, tungsten is found naturally on Earth only in chemical compounds. It was identified as a new element in 1781, and first isolated as a metal in 1783. Its important ores include wolframite and scheelite. The free element is remarkable for its robustness, especially the fact that it has the highest melting point of all the non-alloyed metals and the second highest of all the elements after carbon. Also remarkable is its high density of 19.3 times that of water, comparable to that of uranium and gold, and much higher (about 1.7 times) than that of lead. Tungsten with minor amounts of impurities is often brittle and hard, making it difficult to work. However, very pure tungsten, though still hard, is more ductile, and can be cut with a hard-steel hacksaw.

The unalloyed elemental form is used mainly in electrical applications. Tungsten's many alloys have numerous applications, most notably in incandescent light bulb filaments, X-ray tubes (as both the filament and target), electrodes in TIG welding, and superalloys. Tungsten's hardness and high density give it military applications in penetrating projectiles. Tungsten compounds are most often used industrially as catalysts.

Tungsten is the only metal from the third transition series that is known to occur in biomolecules, where it is used in a few species of bacteria. It is the heaviest element known to be used by any living organism. Tungsten interferes with molybdenum and copper metabolism, and is somewhat toxic to animal life.

Rhenium
Rhenium is a chemical element with the symbol Re and atomic number 75. It is a silvery-white, heavy, third-row transition metal in group 7 of the periodic table. With an estimated average concentration of 1 part per billion (ppb), rhenium is one of the rarest elements in the Earth's crust. The free element has the third-highest melting point and highest boiling point of any element. Rhenium resembles manganese chemically and is obtained as a by-product of molybdenum and copper ore's extraction and refinement. Rhenium shows in its compounds a wide variety of oxidation states ranging from −1 to +7.

Discovered in 1925, rhenium was the last stable element to be discovered. It was named after the river Rhine in Europe.

Nickel-based superalloys of rhenium are used in the combustion chambers, turbine blades, and exhaust nozzles of jet engines, these alloys contain up to 6% rhenium, making jet engine construction the largest single use for the element, with the chemical industry's catalytic uses being next-most important. Because of the low availability relative to demand, rhenium is among the most expensive of metals, with an average price of approximately US$4,575 per kilogram (US$142.30 per troy ounce) as of August 2011; it is also of critical strategic military importance, for its use in high performance military jet and rocket engines.

Osmium
Osmium is a chemical element with the symbol Os and atomic number 76. It is a hard, brittle, blue-gray or blue-black transition metal in the platinum family and is the densest naturally occurring element, with a density of $22.59 g/cm3$ (slightly greater than that of iridium and twice that of lead). It is found in nature as an alloy, mostly in platinum ores; its alloys with platinum, iridium, and other platinum group metals are employed in fountain pen tips, electrical contacts, and other applications where extreme durability and hardness are needed.

Iridium
Iridium is the chemical element with atomic number 77, and is represented by the symbol Ir. A very hard, brittle, silvery-white transition metal of the platinum family, iridium is the second-densest element (after osmium) and is the most corrosion-resistant metal, even at temperatures as high as 2000 °C. Although only certain molten salts and halogens are corrosive to solid iridium, finely divided iridium dust is much more reactive and can be flammable.

Iridium was discovered in 1803 among insoluble impurities in natural platinum. Smithson Tennant, the primary discoverer, named the iridium for the goddess Iris, personification of the rainbow, because of the striking and diverse colors of its salts. Iridium is one of the rarest elements in the Earth's crust, with annual production and consumption of only three tonnes. and are the only two naturally occurring isotopes of iridium as well as the only stable isotopes; the latter is the more abundant of the two.

The most important iridium compounds in use are the salts and acids it forms with chlorine, though iridium also forms a number of organometallic compounds used in industrial catalysis, and in research. Iridium metal is employed when high corrosion resistance at high temperatures is needed, as in high-end spark plugs, crucibles for recrystallization of semiconductors at high temperatures, and electrodes for the production of chlorine in the chloralkali process. Iridium radioisotopes are used in some radioisotope thermoelectric generators.

Iridium is found in meteorites with an abundance much higher than its average abundance in the Earth's crust. For this reason the unusually high abundance of iridium in the clay layer at the Cretaceous–Paleogene boundary gave rise to the Alvarez hypothesis that the impact of a massive extraterrestrial object caused the extinction of dinosaurs and many other species 66 million years ago. It is thought that the total amount of iridium in the planet Earth is much higher than that observed in crustal rocks, but as with other platinum group metals, the high density and tendency of iridium to bond with iron caused most iridium to descend below the crust when the planet was young and still molten.

Platinum
Platinum is a chemical element with the chemical symbol Pt and an atomic number of 78.

Its name is derived from the Spanish term platina, which is literally translated into "little silver". It is a dense, malleable, ductile, precious, gray-white transition metal.

Platinum has six naturally occurring isotopes. It is one of the rarest elements in the Earth's crust and has an average abundance of approximately 5 μg/kg. It is the least reactive metal. It occurs in some nickel and copper ores along with some native deposits, mostly in South Africa, which accounts for 80% of the world production.

As a member of the platinum group of elements, as well as of the group 10 of the periodic table of elements, platinum is generally non-reactive. It exhibits a remarkable resistance to corrosion, even at high temperatures, and as such is considered a noble metal. As a result, platinum is often found chemically uncombined as native platinum. Because it occurs naturally in the alluvial sands of various rivers, it was first used by pre-Columbian South American natives to produce artifacts. It was referenced in European writings as early as 16th century, but it was not until Antonio de Ulloa published a report on a new metal of Colombian origin in 1748 that it became investigated by scientists.

Platinum is used in catalytic converters, laboratory equipment, electrical contacts and electrodes, platinum-resistance thermometers, dentistry equipment, and jewelry. Because only a few hundred tonnes are produced annually, it is a scarce material, and is highly valuable. Being a heavy metal, it leads to health issues upon exposure to its salts, but due to its corrosion resistance, it is not as toxic as some metals. Its compounds, most notably cisplatin, are applied in chemotherapy against certain types of cancer.

Gold
Gold is a dense, soft, shiny, malleable and ductile metal. It is a chemical element with the symbol Au and atomic number 79.

Pure gold has a bright yellow color and luster traditionally considered attractive, which it maintains without oxidizing in air or water. Chemically, gold is a transition metal and a group 11 element. It is one of the least reactive chemical elements solid under standard conditions. The metal therefore occurs often in free elemental (native) form, as nuggets or grains in rocks, in veins and in alluvial deposits. Less commonly, it occurs in minerals as gold compounds, usually with tellurium.

Gold resists attacks by individual acids, but it can be dissolved by the aqua regia (nitro-hydrochloric acid), so named because it dissolves gold. Gold also dissolves in alkaline solutions of cyanide, which have been used in mining. Gold dissolves in mercury, forming amalgam alloys. Gold is insoluble in nitric acid, which dissolves silver and base metals, a property that has long been used to confirm the presence of gold in items, giving rise to the term the acid test.

Gold has been a valuable and highly sought-after precious metal for coinage, jewelry, and other arts since long before the beginning of recorded history. Gold standards have been a common basis for monetary policies throughout human history, later being supplanted by fiat currency starting in the 1930s. The last gold certificate and gold coin currencies were issued in the U.S. in 1932. In Europe, most countries left the gold standard with the start of World War I in 1914 and, with huge war debts, failed to return to gold as a medium of exchange.

A total of 165,000 tonnes of gold have been mined in human history, as of 2009. This is roughly equivalent to 5.3 billion troy ounces or, in terms of volume, about 8500 m3, or a cube 20.4 m on a side. The world consumption of new gold produced is about 50% in jewelry, 40% in investments, and 10% in industry.

Besides its widespread monetary and symbolic functions, gold has many practical uses in dentistry, electronics, and other fields. Its high malleability, ductility, resistance to corrosion and most other chemical reactions, and conductivity of electricity led to many uses of gold, including electric wiring, colored-glass production and even gold leaf eating.

It has been claimed that most of the Earth's gold lies at its core, the metal's high density having made it sink there in the planet's youth. Virtually all of the gold that mankind has discovered is considered to have been deposited later by meteorites which contained the element. This supposedly explains why, in prehistory, gold appeared as nuggets on the earth's surface.

Mercury
Mercury is a chemical element with the symbol Hg and atomic number 80. It is also known as quicksilver or hydrargyrum ( < Greek "hydr-" water and "argyros" silver). A heavy, silvery d-block element, mercury is the only metal that is liquid at standard conditions for temperature and pressure; the only other element that is liquid under these conditions is bromine, though metals such as caesium, francium, gallium, and rubidium melt just above room temperature. With a freezing point of −38.83 °C and boiling point of 356.73 °C, mercury has one of the narrowest ranges of its liquid state of any metal.

Mercury occurs in deposits throughout the world mostly as cinnabar (mercuric sulfide). The red pigment vermilion is mostly obtained by reduction from cinnabar. Cinnabar is highly toxic by ingestion or inhalation of the dust. Mercury poisoning can also result from exposure to water-soluble forms of mercury (such as mercuric chloride or methylmercury), inhalation of mercury vapor, or eating seafood contaminated with mercury.

Mercury is used in thermometers, barometers, manometers, sphygmomanometers, float valves, mercury switches, and other devices though concerns about the element's toxicity have led to mercury thermometers and sphygmomanometers being largely phased out in clinical environments in favor of alcohol-filled, galinstan-filled, digital, or thermistor-based instruments. It remains in use in scientific research applications and in amalgam material for dental restoration. It is used in lighting: electricity passed through mercury vapor in a phosphor tube produces short-wave ultraviolet light which then causes the phosphor to fluoresce, making visible light.

Thallium
Thallium is a chemical element with the symbol Tl and atomic number 81. This soft gray other metal resembles tin but discolors when exposed to air. The two chemists William Crookes and Claude-Auguste Lamy discovered thallium independently in 1861 by the newly developed method of flame spectroscopy. Both discovered the new element in residues of sulfuric acid production.

Approximately 60–70% of thallium production is used in the electronics industry, and the remainder is used in the pharmaceutical industry and in glass manufacturing. It is also used in infrared detectors. Thallium is highly toxic and was used in rat poisons and insecticides. Its use has been reduced or eliminated in many countries because of its nonselective toxicity. Because of its use for murder, thallium has gained the nicknames "The Poisoner's Poison" and "Inheritance Powder" (alongside arsenic).

Lead
Lead is a main-group element in the carbon group with the symbol Pb (from plumbum) and atomic number 82. Lead is a soft, malleable other metal. It is also counted as one of the heavy metals. Metallic lead has a bluish-white color after being freshly cut, but it soon tarnishes to a dull grayish color when exposed to air. Lead has a shiny chrome-silver luster when it is melted into a liquid.

Lead is used in building construction, lead-acid batteries, bullets and shots, weights, as part of solders, pewters, fusible alloys and as a radiation shield. Lead has the highest atomic number of all of the stable elements, although the next higher element, bismuth, has a half-life that is so long (much longer than the age of the universe) that it can be considered stable. Its four stable isotopes have 82 protons, a magic number in the nuclear shell model of atomic nuclei.

Lead, at certain exposure levels, is a poisonous substance to animals as well as for human beings. It damages the nervous system and causes brain disorders. Excessive lead also causes blood disorders in mammals. Like the element mercury, another heavy metal, lead is a neurotoxin that accumulates both in soft tissues and the bones. Lead poisoning has been documented from ancient Rome, ancient Greece, and ancient China.

Bismuth
Bismuth is a chemical element with symbol Bi and atomic number 83. Bismuth, a trivalent other metal, chemically resembles arsenic and antimony. Elemental bismuth may occur naturally uncombined, although its sulfide and oxide form important commercial ores. The free element is 86% as dense as lead. It is a brittle metal with a silvery white color when newly made, but often seen in air with a pink tinge owing to the surface oxide. Bismuth metal has been known from ancient times, although until the 18th century it was often confused with lead and tin, which each have some of bismuth's bulk physical properties. The etymology is uncertain but possibly comes from Arabic bi ismid meaning having the properties of antimony or German words weisse masse or wismuth meaning "white mass".

Bismuth is the most naturally diamagnetic of all metals, and only mercury has a lower thermal conductivity.

Bismuth has classically been considered to be the heaviest naturally occurring stable element, in terms of atomic mass. Recently, however, it has been found to be very slightly radioactive: its only primordial isotope bismuth-209 decays via alpha decay into thallium-205 with a half-life of more than a billion times the estimated age of the universe.

Bismuth compounds (accounting for about half the production of bismuth) are used in cosmetics, pigments, and a few pharmaceuticals. Bismuth has unusually low toxicity for a heavy metal. As the toxicity of lead has become more apparent in recent years, alloy uses for bismuth metal (presently about a third of bismuth production), as a replacement for lead, have become an increasing part of bismuth's commercial importance.

Polonium
Polonium is a chemical element with the symbol Po and atomic number 84, discovered in 1898 by Marie Skłodowska-Curie and Pierre Curie. A rare and highly radioactive element, polonium is chemically similar to bismuth and tellurium, and it occurs in uraniumores. Polonium has been studied for possible use in heating spacecraft. As it is unstable, all isotopes of polonium are radioactive. There is disagreement as to whether polonium is a post-transition metal or metalloid.

Astatine
Astatine is a radioactive chemical element with the symbol At and atomic number 85. It occurs on the Earth only as the result of decay of heavier elements, and decays away rapidly, so much less is known about this element than its upper neighbors in the periodic table. Earlier studies have shown this element follows periodic trends, being the heaviest known halogen, with melting and boiling points being higher than those of lighter halogens.

Until recently most of the chemical characteristics of astatine were inferred from comparison with other elements; however, important studies have already been done. The main difference between astatine and iodine is that the HAt molecule is chemically a hydride rather than a halide; however, in a fashion similar to the lighter halogens, it is known to form ionic astatides with metals. Bonds to nonmetals result in positive oxidation states, with +1 best portrayed by monohalides and their derivatives, while the higher are characterized by bond to oxygen and carbon. Attempts to synthesize astatine fluoride have been met with failure. The second longest-living astatine-211 is the only one to find a commercial use, being useful as an alpha emitter in medicine; however, only extremely small quantities are used, and in larger ones it is very hazardous, as it is intensely radioactive.

Astatine was first produced by Dale R. Corson, Kenneth Ross MacKenzie, and Emilio Segrè in the University of California, Berkeley in 1940. Three years later, it was found in nature; however, with an estimated amount of less than 28 grams (1 oz) at given time, astatine is the least abundant element in Earth's crust among non-transuranium elements. Among astatine isotopes, four (with mass numbers 215, 217, 218 and 219) are present in nature as the result of decay of heavier elements; however, the most stable astatine-210 and the industrially used astatine-211 are not.

Radon
Radon is a chemical element with symbol Rn and atomic number 86. It is a radioactive, colorless, odorless, tasteless noble gas, occurring naturally as the decay product of uranium or thorium. Its most stable isotope, 222Rn, has a half-life of 3.8 days. Radon is one of the densest substances that remains a gas under normal conditions. It is also the only gas that is radioactive under normal conditions, and is considered a health hazard due to its radioactivity. Intense radioactivity also hindered chemical studies of radon and only a few compounds are known.

Radon is formed as part of the normal radioactive decay chain of uranium and thorium. Uranium and thorium have been around since the earth was formed and their most common isotope has a very long half-life (14.05 billion years). Uranium and thorium, radium, and thus radon, will continue to occur for millions of years at about the same concentrations as they do now. As the radioactive gas of radon decays, it produces new radioactive elements called radon daughters or decay products. Radon daughters are solids and stick to surfaces such as dust particles in the air. If contaminated dust is inhaled, these particles can stick to the airways of the lung and increase the risk of developing lung cancer.

Radon is responsible for the majority of the public exposure to ionizing radiation. It is often the single largest contributor to an individual's background radiation dose, and is the most variable from location to location. Radon gas from natural sources can accumulate in buildings, especially in confined areas such as attics and basements. It can also be found in some spring waters and hot springs.

Epidemiological studies have shown a clear link between breathing high concentrations of radon and incidence of lung cancer. Thus, radon is considered a significant contaminant that affects indoor air quality worldwide. According to the United States Environmental Protection Agency, radon is the second most frequent cause of lung cancer, after cigarette smoking, causing 21,000 lung cancer deaths per year in the United States. About 2,900 of these deaths occur among people who have never smoked. While radon is the second most frequent cause of lung cancer, it is the number one cause among non-smokers, according to EPA estimates.

Biological role
Of the period 6 elements, only tungsten and the early lanthanides are known to have any biological role in organisms, and even then only in lower organisms (not mammals). However, gold, platinum, mercury, and some lanthanides such as gadolinium have applications as drugs.

Toxicity
Most of the period 6 elements are toxic (for instance lead) and produce heavy-element poisoning. Promethium, polonium, astatine and radon are radioactive, and therefore present radioactive hazards.

title: Period 6 element


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Waypoint

A waypoint is an intermediate point or place on a route or line of travel, a stopping point or point at which course is changed, the first use of the term tracing to 1880. In modern terms, it most often refers to coordinates which specify one's position on the globe at the end of each "leg" (stage) of an air flight or sea passage, the generation and checking of which are generally done computationally (with a computer or other programmed device).

Hence, the term connotes a reference point in physical space, most often associated with navigation, especially in the sea or air—e.g., in the case of sea navigation, a longitudinal and latitudinal coordinate or a GPS point in open water, a location near a known mapped shoal or other entity in a body of water, a point a fixed distance off of a geographical entity such as a lighthouse or harbour entrance, etc. When such a point corresponds to an element of physical geography on land, it can be referred to as a landmark. In air navigation, waypoints most often consist of a series of abstract GPS points that create artificial airways—"highways in the sky"—created specifically for purposes of air navigation that have no clear connection to features of the real world.

Concept
Waypoints are sets of coordinates that identify a point in physical space. Coordinates used can vary depending on the application. For terrestrial navigation these coordinates can include longitude and latitude. Air navigation also includes altitude. Waypoints have only become widespread for navigational use by the layman since the development of advanced navigational systems, such as the Global Positioning System (GPS) and certain other types of radio navigation. Waypoints located on the surface of the Earth are usually defined in two dimensions (e.g., longitude and latitude); those used in the Earth's atmosphere or in outer space are defined in at least three dimensions (four if time is one of the coordinates, as it might be for some waypoints outside the Earth).

Although the term waypoint has only entered common use in recent years, the equivalent of a waypoint in all but name has existed for as long as human beings have navigated. Waypoints have traditionally been associated with distinctive features of the real world, such as rock formations, springs, oases, mountains, buildings, roadways, waterways, railways, and so on. Today, these associations persist, but waypoints are more often associated with physical artifacts created specifically for navigation, such as radio beacons, buoys, satellites or control points.

In the modern world, waypoints are increasingly abstract, often having no obvious relationship to any distinctive features of the real world. These waypoints are used to help define invisible routing paths for navigation. For example, artificial airways "highways in the sky", created specifically for purposes of air navigation, often have no clear connection to features of the real world, and consist only of a series of abstract waypoints in the sky through which pilots navigate; these airways are designed to facilitate air traffic control and routing of traffic between heavily traveled locations, and do not reference natural terrain features. Abstract waypoints of this kind have been made practical by modern navigation technologies, such as land-based radio beacons and the satellite-based GPS.

Abstract waypoints typically have only specified longitude and latitude or UTM coordinates plus the reference datum, and often a name if they are marked on charts, and are located using a radio navigation system such as a VOR or GPS receiver. A waypoint can be a destination, a fix along a planned course used to make a journey, or simply a point of reference useful for navigation.

With GPS
GPS systems are increasingly used to create and use waypoints in navigation of all kinds. A typical GPS receiver can locate a waypoint with an accuracy of three meters or better when used with land-based assisting technologies such as the Wide Area Augmentation System (WAAS). Waypoints can also be marked on a computer mapping program and uploaded to the GPS receiver, marked on the receiver's own internal map, or entered manually on the device as a pair of coordinates.

If the GPS receiver has track-logging capabilities, one can also define waypoints after the fact from where one has been. For example, marine GPS receivers often have a "man overboard" function, which instantly creates a waypoint in the receiver for the boat's position when enabled and then begins displaying the distance and course back to that position.

In GPS navigation, a "route" is usually defined as a series of two or more waypoints. To follow such a route, the GPS user navigates to the nearest waypoint, then to the next one in turn until the destination is reached. Most receivers have the ability to compute a great circle route towards a waypoint, enabling them to find the shortest route even over long distances, although waypoints are often so closely spaced that this is not a factor.

Many GPS receivers, both military and civilian, now offer integrated cartographic databases (also known as base maps), allowing users to locate a point on a map and define it as a waypoint. Some GPS systems intended for automobile navigation can generate a suggested driving route between two waypoints, based on the cartographic database. As one drives along the route, the system indicates the driver's current location and gives advance notice of upcoming turns. The best of these systems can take into account traffic restrictions such as one-way streets and intersections where left or right turns are prohibited when computing the suggested driving route.

Most GPS receivers allow the user to assign a name to each waypoint. Many models also let the user select a symbol or icon to identify the waypoint on a graphical map display from a built-in library of icons. These include standard map symbols for marine navigation aids such as buoys, marinas and anchorages, as well as land-based landmarks such as churches, bridges, shopping centers, parks and tunnels.

GPS receivers used in air navigation have databases which contain named waypoints, radio navigation aids, airports and heliports. These references comprise the National Airspace System's method of allowing air traffic to select routes that yield efficient point-to-point navigation. Waypoints are often used in the termination phase of a flight to its destination airport. Some GPS receivers are integrated into autopilot or flight management systems, to aid the pilot in control of an aircraft. Waypoints may be found on Aeronautical Charts known as Instrument Flight Rules Enroute Low Altitude Charts, Terminal Arrival Procedures or Sectional Charts.

Without GPS
Although the concept of waypoints has been greatly popularized among non-specialists by the development of the GPS, waypoints can be used with other navigational aids. A notable example is the worldwide use, in orienteering sports, of waypoints with a map that omits a coordinate system, known as control points.

In aerial celestial navigation, waypoints are precomputed along an aircraft's great circle route to divide the flight into rhumb lines and allow celestial fixes to be more rapidly taken using the precomputed intercept method.

In air navigation, waypoints are sometimes defined as intersections between two VOR radials or NDB bearings, or in terms of specific distances and headings towards or away from a radio beacon. For visual air navigation (see the article on visual flight rules), waypoints may be directly associated with distinctive features on the ground that are easily identifiable from aircraft, such as stadiums, power plants, racetracks, etc. Temporary waypoints are sometimes defined as traffic requires, e.g., air-traffic controllers may instruct a pilot to reference a terrain feature at "your ten o'clock position, two miles."

In aviation
In aviation, area navigation (RNAV)—a method of navigation that permits aircraft operation on any desired flight path within the coverage of station-referenced navigation aids or within the limits of the capability of self-contained aids, or a combination of these—relies heavily upon waypoints. RNAV is increasingly used as the primary method of navigation for aircraft.

In the RNAV context, a waypoint is a predetermined geographical position that is defined in terms of latitude/longitude coordinates (altitude is ignored). Waypoints may be a simple named point in space or may be associated with existing navigational aids, intersections, or fixes. A waypoint is most often used to indicate a change in direction, speed, or altitude along the desired path.

Aviation RNAV procedures make use of both fly-over and fly-by waypoints. A fly-over waypoint is a waypoint that must be crossed vertically by an aircraft. A fly-by waypoint is a waypoint that marks the intersection of two straight paths, with the transition from one path to another being made by the aircraft using a precisely calculated turn that "flies by" but does not vertically cross the waypoint.

Waypoints used in aviation are given five-letter names. These names are meant to be pronounceable or have a mnemonic value, so that they may easily be conveyed by voice. In some cases the names correspond to a notable feature or landmark in the area (for example, a waypoint near Newton, Iowa, has the name "MATAG"; Newton was where appliance manufacturer Maytag was founded).

title: Waypoint