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Emmaus

Emmaus (Greek: Ἐμμαούς, Emmaous; Emmaus; عمواس, ʻImwas) is a town mentioned in the Gospel of Luke of the New Testament. Luke reports that Jesus appeared, after his death and resurrection, before two of his disciples while they were walking on the road to Emmaus.

Although its geographical identification is not certain, several locations have been suggested throughout history, chiefly Imwas and Al-Qubeiba, both in the West Bank. It is known only that it was connected by a road to Jerusalem; the distance given by Luke varies in different manuscripts and the figure given has been made even more ambiguous by interpretations.

Names and location
The place-name Emmaus is relatively common in classical sources about the Levant and is usually derived through Greek and Latin from the Semitic word for "warm spring", the Hebrew form of which is hamma or hammat (חמת). In the ancient and present-day Middle East, many sites are named Hama Hamath and variations thereof.

The name for Emmaus was hellenized during the 2nd century BC and appears in Jewish and Greek texts in many variations: Ammaus, Ammaum, Emmaus, Emmaum, Maus, Amus, etc.: Άμμαούμ, Άμμαούς, Έμμαούμ, Έμμαούς, אמאוס, אמאום, עמאוס, עמאום, עמוס, מאום, אמהום

Emmaus may derive from the Hebrew ḥammat (חמת) meaning "hot spring", although this remains uncertain. It is generally referred to in Hebrew sources as Ḥamtah or Ḥamtān. A spring of Emmaus (Ἐμμαοῦς πηγή), or alternatively a 'spring of salvation' (πηγή σωτήριος) is attested in Greek sources. Unlike other Biblical or Mishnaic sites with the name "Ḥamah" and where the traditional Hebrew spelling has been preserved in classical texts throughout the ages, Emmaus differs insofar that the traditional Hebrew spelling for this place in most classical sources is  or. During the late Second Temple period, Emmaus was renamed Nicopolis ("City of Victory"), a name remained in use as late as the 6th-century Madaba Map. Emmaus is mentioned by this name in Midrash Zutta for Song of Songs 6,8 and Midrash Rabba for Lamentations 1,45, and in the Midrash Rabba on Ecclesiastes (7:15). According to Sozomen (fl.400–450), it was renamed by the Romans "in consequence of the conquest of Jerusalem and the victory over the Jews."

Emmaus in the New Testament

Emmaus is mentioned in the Gospel of Luke as the village where Jesus appeared to his disciples after his crucifixion and resurrection. indicates that Jesus appears after his resurrection to two disciples who are walking from Jerusalem to Emmaus, which is described as being 60 stadia (10.4 to 12 km depending on what definition of stadion is used) from Jerusalem. One of the disciples is named Cleopas (verse 18), while his companion remains unnamed: That very day two of them were going to a village (one hundred and) sixty stadia away from Jerusalem called Emmaus, and they were speaking about all the things that had occurred. And it happened that while they were speaking and debating, Jesus himself drew near and walked with them, but their eyes were prevented from recognizing him … As they approached the village to which they were going, he gave the impression that he was going on further. But they urged him, "Stay with us, for it is nearly evening and the day is declining." So he went in to stay with them. And it happened that, while he was with them at table, he took bread, said the blessing, broke it, and gave it to them. With that their eyes were opened and they recognized him.

According to the gospel, the story takes place in the evening of the day of Jesus's resurrection. The two disciples hear that the tomb of Jesus was found empty earlier that day. They are discussing the events of the past few days when a stranger asks them what they are discussing. "Their eyes were kept from recognizing him." He rebukes them for their unbelief and explains prophecies about the Messiah to them. On reaching Emmaus, they ask the stranger to join them for the evening meal.

When he breaks the bread, "their eyes [are] opened" and they recognize him as the resurrected Christ. Jesus immediately vanishes. Cleopas and his friend then hasten back to Jerusalem to carry the news to the other disciples.

A similar event is mentioned in the Gospel of Mark, although the disciples' destination is not stated. This passage is believed by some to be a late addition, derived from the Gospel of Luke.

The incident is not mentioned in the Gospels of Matthew or John.

Possible locations
Emmaus is the Greek variant of the Hebrew word and place-name for hot springs, hammat, and is therefore not unique to one location, which makes the identification of the New Testament site more difficult.

Several places in Judea and Galilee are called Emmaus in the Bible, the works of Josephus Flavius, and other sources from the relevant period. The one most often mentioned is a town of some importance situated in the Valley of Ajalon (today, Ayyalon), later called Emmaus Nicopolis.

Historical identification
Many sites have been suggested for the biblical Emmaus, among them Emmaus Nicopolis (c. 160 stadia from Jerusalem), Kiryat Anavim (66 stadia from Jerusalem on the carriage road to Jaffa), Coloniya (c. 36 stadia on the carriage road to Jaffa), el-Kubeibeh (63 stadia, on the Roman road to Lydda), Artas (60 stadia from Jerusalem) and Khurbet al-Khamasa (86 stadia on the Roman road to Eleutheropolis). The oldest identification that is currently known is Emmaus Nicopolis. The identification is complicated by the fact that New Testament manuscripts list at least three different distances between Jerusalem and Emmaus in Luke 24:13-14.

Emmaus Nicopolis/Imwas
The first modern site identification of Emmaus was by the explorer Edward Robinson, who equated it with the Palestinian Arab village of Imwas (عِمواس), near the Latrun Abbey. Before its destruction in 1967, the village of Imwas was located at the end of the Ayalon Valley, on the border of the hill country of Judah, at 153 stadia (18.6 miles) from Jerusalem via the Kiryat Yearim Ridge Route, 161 stadia (19.6 miles) via the Beth-Horon Ridge Route and 1600 ft lower by elevation.

Eusebius was probably the first to mention Nicopolis as biblical Emmaus in his Onomasticon. Jerome, who translated Eusebius' book, implied in his letter 108 that there was a church in Nicopolis built in the house of Cleopas where Jesus broke bread on that late journey. From the 4th century on, the site was commonly identified as the biblical Emmaus.

Emmaus Nicopolis appears on Roman geographical maps. The Peutinger Table situates it about 19 mi west of Jerusalem, while the Ptolemy map shows it at a distance of 20 mi from the city. The Emmaus in the Gospel of Luke seems to lie some 7.5 mi from Jerusalem, though a textual minor variant, conserved in Codex Sinaiticus, gives the distance between the New Testament Emmaus and Jerusalem as 160 stadia. The geographical position of Emmaus is described in the Jerusalem Talmud, Tractate Sheviit 9.2: From Bet Horon to the Sea is one domain. Yet is it one domain without regions? Rabbi Johanan said, "Still there is Mountain, Lowland, and Valley. From Bet Horon to Emmaus (אמאום) it is Mountain, from Emmaus to Lydda Lowland, from Lydda to the Sea Valley. Then there should be four stated? They are adjacent."

Archaeologically, many remains have been excavated at the site of the former Palestinian village, now located inside Canada Park, which support historical and traditional claims. Five structures were found and dated, including a Christian basilica from the 6th century and a 12th-century Crusader church. Emmaus Nicopolis is a titular see of the Roman Catholic Church.

There are several sources giving information about this town's ancient history, among them the First Book of Maccabees, the works of Josephus, and chronicles from the Late Roman, Byzantine and Early Muslim periods. According to 1 Maccabees 3:55-4:22, around 166 BC Judas Maccabeus fought against the Seleucids in the region of this particular Emmaus, and was victorious at the Battle of Emmaus; later, this town was fortified by Bacchides, a Seleucid general (1 Macc 9:50). When Rome took over the land it became the capital of a district or toparchy, and was burnt by order of Varus after the death of Herod in 4 BC. During the First Jewish Revolt, before the siege of Jerusalem, Vespasian's 5th legion was deployed there while the 10th Legion was in Jericho. The town was renamed Emmaus Nicopolis in AD 221 by Emperor Elagabalus, who conferred it the title of polis ("city") following the request of a delegation from Emmaus. The Plague of Emmaus in AD 639, mentioned in Muslim sources, is claimed to have caused up to 25,000 deaths in the town.

Nicopolis (Νικόπολις, Nikópolis) was the name of Emmaus (אמאוס; Ἀμμαοῦς, Ammaoûs; عِمواس, Imwas) under the Roman Empire until the conquest of Palestine by the Rashidun Caliphate in 639. The Church Fathers unanimously considered this city to be the Emmaus of the New Testament where Jesus was said to have appeared after his death and resurrection; it is sometimes distinguished from other Emmauses of Palestine and other Nicopolises of the Roman Empire by the combined name Emmaus Nicopolis or Emmaus-Nicopolis. The site of the ancient city now lies between Tel Aviv and Jerusalem in Israel. A Palestinian Arab village occupied the site until the Six-Day War in 1967, when it was destroyed. The archaeological site has been cared for by a resident French Catholic community since 1993 but are formally organized as a part of Canada Park under the general supervision of the Israel Nature and Parks Authority.

Hellenistic, Hasmonean period
Due to its strategic position, Emmaus played an important administrative, military and economic role in history. The first mention of Emmaus occurs in the First Book of Maccabees, chapters 3–4, in the context of Judas Maccabeus and his revolt against the Greek Seleucid Empire in the 2nd century. The first major battle of the revolt, the Battle of Emmaus, is traditionally believed to have occurred in this area, with the Seleucids establishing a fortified camp here from which to control the countryside. During the Hasmonean period, Emmaus became a regional administrative centre (toparchy) in the Ayalon Valley.

According to one theory, Emmaus of the Hasmonean and early Roman periods was located at Horvat 'Eqed.

Roman period

Josephus Flavius mentions Emmaus in his writings several times. He speaks about the destruction of Emmaus by the Romans in the year 4. The importance of the city was recognized by the Emperor Vespasian, who established a fortified camp there in 68 to house the fifth ("Macedonian") legion, populating it with 800 veterans, though this may refer to Qalunya rather than Emmaus Nicopolis. Archaeological works indicate that the town was cosmopolitan, with a mixed Jewish, pagan and Samaritan population, the presence of the last group being attested by the remains of a Samaritan synagogue. In 130 or 131, the city was destroyed by an earthquake. In 132, the ruins of Emmaus fortress were briefly reconstructed by Judean rebels under Simon Bar Kokhba and used as a hideout during the revolt.

The city of Nicopolis was founded on the ruins of Emmaus in early 3rd century, after Julius Africanus, who said he had interviewed descendants of Jesus' relatives, headed an embassy to Rome and had an interview with the Roman emperor Elagabalus on behalf of Emmaus, then a small Palestinian village (κώμη). St. Eusebius writes "Emmaus, whence was Cleopas who is mentioned by the Evangelist Luke. Today it is Nicopolis, a famous city of Palestine." In 222, a basilica was erected there, which was rebuilt first by the Byzantines and later modified by the Crusaders.

Byzantine period
During the Byzantine period Nicopolis became a large city and a bishopric. A substantial church complex was erected on the spot where tradition maintained the apparition of the risen Christ had occurred, a site which then became a place of pilgrimage, and whose ruins are still extant.

Early Muslim period
At the time of the Islamic conquest of Palestine, the main encampment of the Arab army was established in Emmaus, when a plague (ța'ūn) struck, carrying off many of Companions of the Prophet. This first encounter of the Arab armies with the chronic plagues of Syria was later referred to as the 'plague of 'Amawās', a and the event marked the decline of Emmaus Nicopolis. A well on the site still bears an inscription reading "the well of the plague" (bi'r aț-ța'ūn).

Crusader period
During the Crusader period, the Christian presence resumed at Emmaus, and the Byzantine church was restored. However, the memory of the apparition of the risen Jesus at Emmaus also started to be celebrated in three other places in the Holy Land: Motza (c. 4 mi west of Jerusalem), Qubeibe (c. 7 mi northwest of Jerusalem), and Abu Ghosh (c. 7 mi west of Jerusalem).

Ottoman period
The Arab village of Imwas was identified once again as the biblical Emmaus and the Roman-Byzantine Nicopolis by scholars in the 19th century, including Edward Robinson(1838–1852), M.-V. Guérin (1868), Charles Simon Clermont-Ganneau (1874), and J.-B. Guillemot (1880–1887). Significantly, a local mystic named Saint Mariam of Jesus Crucified, a nun of the Carmelite monastery of Bethlehem, had a revelation while in ecstatic prayer in 1878 in which Jesus appeared to indicate Amwas was the Gospel Emmaus. "She came to the top of a knoll where, amid grass and thorns, there were some freestones leveled. Transported and moved, she turned toward her sisters [in religion], and said to them in a loud voice: 'This is truly the place where our Lord ate with His disciples.'" On the basis of this revelation, the holy place of Emmaus was acquired by the Carmelite order from the Muslims in 1878, excavations were carried out, and the flow of pilgrims to Emmaus resumed.

British Mandate
In 1930, the Carmelite Order built a monastery, the House of Peace, on the tract of land purchased in 1878. In November 1947, the United Nations Partition Plan for Palestine attributed the area to the Arab State. Prior to the outbreak of hostilities in the 1948 Arab–Israeli War, ʻImwâs had a population of 1,100 Arabs.

Jordan
Israelis and Jordanians fought during the battle of Latrun for the control of this strategic zone which blockaded the road to Jerusalem. As part of the outcome of the war the Palestinian village of Imwas, which lay on the site of Emmaus Nicopolis, fell within the West Bank territory under Jordanian rule.

Israel

In 1967, after the Six-Day War the residents of Imwas Israeli forces expelled the population and the village was razed by bulldozers, leaving the Byzantine-crusader church, called in Arabic, al-Kenisah, intact in their cemetery. The Catholic congregation, the Community of the Beatitudes, renovated the site in 1967–1970 and opened the French Center for the Study of the Prehistory of the Land of Israel next to it where they were allowed to settle in 1993.

Subsequently, Canada Park was created in 1973, financed by the Jewish National Fund (JNF) of Canada, and included the plantation of a forest on the rubble of Imwas. The site became a favourite picnic ground for Israelis and the Latrun salient an area of Israeli commemoration of its War of Independence.

Archaeology

Archaeological excavations in Imwas started in the late 19th century and continue nowadays: Clermont-Ganneau (1874), J.-B. Guillemot (1883–1887), Dominican Fathers L.-H. Vincent & F.-M. Abel (1924–1930), Y. Hirschfeld (1975), M. Gichon (1978), Mikko Louhivuori, M. Piccirillo, V. Michel, K.-H. Fleckenstein (since 1994). During excavations in Canada Park ( Ayalon forest) ruins of Emmaus fortifications from the Hasmonean era were discovered, along with a Roman bathhouse from the 3rd century CE, Jewish burial caves from the 1st century CE, Roman-Byzantine hydraulic installations, oil presses and tombs. Other findings were coins, oil lamps, vessels, jewellery. The eastern (rear) three-apsidal wall of the Byzantine church was cleared, with an external baptistery and polychrome mosaics, as well as walls of the Crusader church which were built against the central Byzantine apse (12th century). In the area of Emmaus, several Hebrew, Samaritan, Greek and Latin inscriptions carved on stones have been found.

Identification with the Gospel site
Most manuscripts of the Gospel of Luke which came down to us indicate the distance of 60 stadia (c. 11 km) between Jerusalem and Emmaus. However, there are several manuscripts which state the distance as 160 stadia (31 km). These include the uncial manuscripts א (Codex Sinaiticus), Θ, Ν, Κ, Π, 079 and cursive (minuscule) manuscripts 158, 175, 223, 237, 420, as well as ancient lectionaries and translations into Latin (some manuscripts of the Vetus Latina, high-quality manuscripts of the Vulgate ), in Aramaic, Georgian and Armenian languages. The version of 60 stadia has been adopted for the printed editions of the Gospel of Luke since the 16th century. The main argument against the version of 160 stadia claims that it is impossible to walk such a distance in one day. In keeping with the principle of Lectio difficilior, lectio verior, the most difficult version is presumed to be genuine, since ancient copyists of the Bible were inclined to change the text in order to facilitate understanding, but not vice versa. It is possible to walk from Jerusalem to Emmaus and back in one day.

The ancient Jewish sources (1 Maccabees, Josephus Flavius, Talmud and Midrash) mention only one village called Emmaus in the area of Jerusalem: Emmaus of Ajalon Valley. For example, in the "Jewish War" (4, 8, 1) Josephus Flavius mentions that Vespasian placed the 5th Macedonian Legion in Emmaus. This has been confirmed by archaeologists who have discovered inscribed tombstones of the Legion's soldiers in the area of Emmaus. (The village of Motza, located 30 stadia (c. 4 mi) away from Jerusalem, is mentioned in medieval Greek manuscripts of the "Jewish war" of Josephus Flavius (7,6,6) under the name of Ammaus, apparently as a result of copyists' mistake).

The ancient Christian tradition of the Church fathers, as well as pilgrims to the Holy Land during the Roman-Byzantine period, unanimously recognized Nicopolis as the Emmaus in the Gospel of Luke (Origen (presumably), Eusebius of Caesarea, St. Jerome, Hesychius of Jerusalem, Theophanes the Confessor, Sozomen, Theodosius, etc.).

Al-Qubeiba/Castellum Emmaus/Chubebe/Qubaibat
Another possibility is the village of al-Qubeiba, west of Nabi Samwil on the Beit Horon road northwest of Jerusalem. The town, meaning "little domes" in Arabic, is located at about 65 stadia from Jerusalem. A Roman fort subsequently named Castellum Emmaus (from the Latin root castra, meaning encampment) was discovered at the site in 1099 by the Crusaders. However, there is no source from the Roman, Byzantine or Early Muslim periods naming it as "Emmaus" for the time of Jesus. Whether Josephus (who puts Emmaus at a distance of thirty stadia from Jerusalem) was referring to this place is now uncertain. However, the Gospel of Luke speaks of 60 stadia (Luke 24:13), a distance very close to the actual 65 stadia to Qubeibeh.

In the 12th century, the Crusaders of the Kingdom of Jerusalem called the site "Small Mahomeria", in order to distinguish it from the "Large Mahomeria" near Ramallah. Sounding similar to "Mahommed", the term was used in medieval times to describe a place inhabited or used for prayer by Muslims. It was referred to as Qubaibat for the first time at the end of that same century by the writer Abu Shama, who writes in his Book of the Two Gardens about a Muslim prince falling into the hands of the Crusaders at this spot. The Franciscans built a church here in 1902, on the ruins of a Crusader basilica.

During the Second World War, British authorities held Franciscans of Italian and German nationality at Emmaus-Qubeibeh. While there, Bellarmino Bagatti conducted excavations from 1940 to 1944 which revealed artifacts from the Hellenistic, Roman, Byzantine, and Crusader periods. Inspired by Bagatti's work, Virgilio Canio Corbo also undertook some experimental explorations.

Abu-Ghosh/Kiryat Anavim
Abu Ghosh is located in the middle of the Kiryat Yearim Ridge Route between Nicopolis and Jerusalem, nine miles (83 stadia) from the capital. A former Minorite convent with a Gothic church was turned into a stable. Robinson dated it to the Crusader period and declared it "more perfectly preserved than any other ancient church in Palestine." Excavations carried out in 1944 supported the identification with Fontenoid, a site the Crusaders held for a while to be Emmaus before accepting Nicopolis as the "real" Emmaus.

Emmaus/Colonia/Motza/Ammassa/Ammaous/Khirbet Mizza
Colonia, between Abu Ghosh and Jerusalem on the Kiryat Yearim Ridge Route, is another possibility. At a distance of c. 8 km from Jerusalem, it was referred to as Mozah in the Old Testament. Listed among the Benjamite cities of, it was referred to in the Talmud as a place where people would come to cut young willow branches as a part of the celebration of Sukkot (Mishnah, Sukkah 4.5: 178). Motza was identified as the Emmaus of Luke in 1881 by William F. Birch (1840–1916) of the Palestine Exploration Fund, and again in 1893 by Paulo Savi. One mile to the north of modern Motza is a ruin called Khirbet Beit Mizza, which was identified by some scholars as the biblical Mozah, until recent excavations placed Mozah at Khirbet Mizza (without "Beit"), as the ruins of Qalunya/Colonia are called in Arabic.

Excavations in 2001-2003 headed by Professor Carsten Peter Thiede were cut short by his sudden death in 2004. Thiede was a strong proponent of Motza as the real Emmaus. He offered that the Latin Amassa and the Greek Ammaous are derived from the biblical Hebrew name Motza: Motza – ha-Motza ("ha" is the Hebrew equivalent of the definite article "the") – ha-Mosa – Amosa – Amaous – Emmaus. His excavation summaries were removed from the website of the Basel college he was teaching at, but a book and at least one article he published on the topic are available. He contended that neither Nicopolis, Abu Ghosh, or Al-Qubeiba can be considered because the first was located too far from Jerusalem, while the two others were not called Emmaus at the time of Jesus.

Josephus Flavius writes in Antiquities of the Jews about a city called Emmaus in the context of the Maccabean Revolt, which corresponds well with the large city later called Emmaus Nicopolis, located at over 170 Roman stadia from Jerusalem, while in The Jewish War he brings up another Emmaus, just 30 Roman stadia from Jerusalem, where Vespasian settled 800 Roman legionnaires after the First Jewish Revolt. The ancient Latin manuscripts use "Amassa", while the medieval Greek manuscripts use "Ammaous". The newly created Roman "colonia" soon made the old name disappear: even the Jewish works of the 3rd-5th centuries, the Mishnah, the Babylonian and the Jerusalem Talmud, talk about "Qeloniya", an Aramaic distortion of "colonia". This name survived into modern times in Arabic as "Qalunya". This was indeed always a village, not a city like Emmaus Nicopolis, and thus fits the description by Luke (κωμη "village") much better than the latter. The difference in distance to Jerusalem between Luke's and Josephus' Emmaus, 60 vs. 30 stadia, is still much smaller than the one to Nicopolis, which lays fully 176 stadia down the Roman road from Jerusalem. Thiede recalculated the actual distance between Jerusalem's western city gate at the time, and his excavation site at Motza which unearthed the Jewish village that predated the Roman veterans colony, and came up with a figure of 46 stadia. That would put it squarely in the middle between Luke's and Josephus' stated distances, which Thiede considers a good approximation for the time. Thiede's excavation produced Jewish artifacts of the time preceding the fall of Jerusalem in 70 CE, giving substance to his claim to have found Luke's Emmaus, which had necessarily to be settled by Jews. With no other Emmaus in the vicinity of Jerusalem, Motza was thus the only credible candidate.

Horvat 'Eqed
Horvat 'Eqed, situated on a hilltop 2 km east of Emmaus Nicopolis, is a recent candidate for the site of ancient Emmaus. This archaeological site features significant fortifications dating back to the second century BC, potentially attributed to the Seleucid general Bacchides and reinforced during the Bar Kokhba revolt, in the early 2nd century AD. Discoveries at the site include ritual baths, a hiding system used during the revolt, as well as various artifacts like Bar Kokhba coinage and weaponry.

According to one theory, Emmaus was originally located at Horvat 'Eqed during the Hellenistic and early Roman periods, and was later abandoned in the aftermath of the Bar Kokhba revolt. The name Emmaus later transferred to the site of Emmaus Nicopolis, where the city was located in the Roman and Byzantine periods.

Possible symbolic identification
One of the oldest extant versions of the Gospel of Luke, preserved in the Codex Bezae, reads "Oulammaus" instead of Emmaus. In Septuagint, the Greek translation of the Old Testament scriptures, Oulammaus was the place where Jacob was visited by God in his dream, while sleeping on a rock. However, Oulammaus was not a real place name but a translation mistake. The original name in Hebrew was "Luz". This mistake was later corrected, but was still there at the time when the Gospel was written around AD 100. Thus, a theory has been put forward, that the story in the Gospel was merely symbolic, drawing a parallel between Jacob being visited by God and the disciples being visited by Jesus.

Richard Carrier (a prominent Jesus "Mythicist"), in his book On the Historicity of Jesus, cites this story as one of two examples of the "Vanishing Hitchhiker" urban legend from antiquity, the other being a legend concerning Romulus, the mythical founder of Rome. The story, found in Livy and Plutarch, tells of Proculus (meaning "Proclaimer" in archaic Latin) journeying by road from Alba Longa to Rome and meeting a stranger who is the resurrected Romulus. Rome is in turmoil because Romulus was recently killed and his body vanished. On their journey, Romulus explains the secrets of the kingdom, in other words how to conquer and rule the world, before ascending into heaven. Proculus then recognises the stranger and goes on to proclaim what he was told. The story recounted in Luke's gospel (Luke 24) parallels the earlier Roman myth: Cleopas (meaning "glory of her father" in Greek), while traveling by road from Jerusalem to Emmaus after learning of the death of Jesus, meets Jesus in disguise. As they walk and eat together, Jesus explains the secrets of the kingdom of heaven. Jesus later vanishes and Cleopas, now realizing who the stranger was, goes on to proclaim what he was told.

Contemporary use
Emmaus, Pennsylvania, a township in the Lehigh Valley region of the United States, draws its name from the Biblical references to Emmaus.

Notable residents

 * Rabbi Akiva

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Jerome Park Reservoir

The Jerome Park Reservoir is a reservoir located in Jerome Park, a neighborhood in the North Bronx, New York City. The reservoir is surrounded by DeWitt Clinton High School, the Bronx High School of Science, Lehman College, and Walton High School.

History

The reservoir was built in 1906 to serve the New Croton aqueduct as part of the New York City water supply system. It is named for Jerome Park Racetrack, a part of the former Old Bathgate Estate (owned by Winston Churchill's maternal grandfather Leonard Walter Jerome 1817–1891, for whom the racetrack was originally named) which opened in 1866 and which was the site of the inaugural Belmont Stakes in 1867. The racetrack was condemned, bought by New York City and closed in 1889 to make way for the reservoir.

In 1996, residents organized under the leadership of Jerome Park Conservancy to stop the city from converting the site to a water treatment plant. It was thought that the noise, chemicals, and unsightly construction would decrease the quality of life for area residents, and have a negative impact on the learning environment at nearby schools.

The reservoir was listed on the National Register of Historic Places in 2000. The related High Pumping Station had been listed in 1983.

The treatment plant was built in another part of the North Bronx underneath Van Cortlandt Park. In connection with this work, the Croton system was taken offline and the reservoir emptied in December 2008. It was refilled and returned to service in early 2014. In November 2015, the DEP experimentally opened the perimeter to the public for tours.

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

title: Jerome Park Reservoir


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Ash Carter

Ashton Baldwin Carter (September 24, 1954 – October 24, 2022) was an American government official and academic who served as the 25th United States secretary of defense from February 2015 to January 2017. He later served as director of the Belfer Center for Science & International Affairs at Harvard Kennedy School.

Carter began his career as a physicist. After a brief experience as an analyst for the Congressional Office of Technology Assessment, he switched careers to public policy. He joined the Kennedy School of Government at Harvard University in 1984 and became chair of the International & Global Affairs faculty. Carter served as Assistant Secretary of Defense for International Security Policy during President Clinton's first term, from 1993 to 1996, responsible for policy regarding the former Soviet states, strategic affairs, and nuclear weapons.

During President Obama's first term, he served first as Under Secretary of Defense for Acquisition, Technology and Logistics and then Deputy Secretary of Defense until December 2013. In February 2015, he replaced Chuck Hagel as Secretary of Defense and served until the end of the Obama administration. During his tenure, he ended the ban of transgender officers in the military. In 2016, Carter opened all military occupations and positions to women without exception. This marked the first time in U.S. history that women with the appropriate qualifications would be allowed to serve in military roles such as infantry, armor, reconnaissance, and special operations units.

For his service to national security, Carter had on five occasions been awarded the DOD Distinguished Public Service Medal. He had also received the CJCS Joint Distinguished Civilian Service Award, and the Defense Intelligence Medal for his contributions to intelligence. Carter was author or co-author of eleven books and more than 100 articles on physics, technology, national security, and management.

Early life
Ashton Baldwin Carter was born on September 24, 1954, in Philadelphia, Pennsylvania. His father is William Stanley Carter Jr., a World War II veteran, United States Navy neurologist and psychiatrist, and department chairman at Abington Memorial Hospital for 30 years. His mother is Anne Baldwin Carter, an English teacher.

He has three siblings, including children's book author Cynthia DeFelice. As a child he was nicknamed Ash and Stoobie.

Carter was raised in Abington, Pennsylvania, on Wheatsheaf Lane. At age eleven, working at his first job at a Philadelphia car wash, he was fired for "wise-mouthing the owner."

Education
Carter was educated at Highland Elementary School (class of 1966) and at Abington Senior High School (class of 1972) in Abington. In high school, he was a wrestler, lacrosse player, cross-country runner, and president of the Honor Society. He was inducted into Abington Senior High School's Hall of Fame in 1989.

Carter attended the University of Edinburgh in Scotland in 1975. In 1976, Carter completed his Bachelor of Arts in his double-major of physics and medieval history at Yale College, summa cum laude, Phi Beta Kappa. His senior thesis, "Quarks, Charm and the Psi Particle", was published in Yale Scientific in 1975. He was also an experimental research associate at Fermi National Accelerator Laboratory in 1975 (where he worked on quark research) and at Brookhaven National Laboratory in 1976.

Carter then became a Rhodes Scholar and studied at the University of Oxford. He received his Doctor of Philosophy in theoretical physics on Hard processes in perturbative QCD in 1979 and was supervised by Christopher Llewellyn Smith. He was a member of St John's College, Oxford.

Carter was subsequently a postdoctoral fellow research associate in theoretical physics at Rockefeller University from 1979 to 1980, studying time-reversal invariance and dynamical symmetry breaking. He coauthored two papers on CP violations in B meson decays with A. I. Sanda, which were used as one of theoretical basis to build B factories.

Carter was then a research fellow at the MIT Center for International Studies from 1982 to 1984, during which time he wrote a public report assessing that the Reagan-proposed "Star Wars" initiative could not protect the U.S. from a Soviet nuclear attack.

Academic career
Carter taught at Harvard University, as an assistant professor from 1984 to 1986, associate professor from 1986 to 1988, professor and associate director of the Center for Science and International Affairs at Harvard University's John F. Kennedy School of Government from 1988 to 1990, and director of the center from 1990 to 1993. At the Kennedy School, he became chair of the International and Global Affairs faculty and Ford Foundation Professor of Science and International Affairs. He concurrently was co-director of the Preventive Defense Project of Harvard and Stanford Universities.

Early Department of Defense career

From 1993 to 1996, Carter served as assistant secretary of defense for international security policy during President Bill Clinton's first term. He was responsible for strategic affairs, including dealing with the threat of weapons of mass destruction elsewhere in the world, nuclear weapons policy (including overseeing the U.S. nuclear arsenal and missile defenses), the 1994 Nuclear Posture Review, the Agreed Framework signed in 1994 which froze North Korea's plutonium-producing nuclear reactor program, the 1995 extension of the Nuclear Non-Proliferation Treaty, the negotiation of the 1996 Comprehensive Nuclear-Test-Ban Treaty, and the multibillion-dollar Nunn-Lugar Cooperative Threat Reduction program and Project Sapphire that removed all nuclear weapons from Ukraine, Kazakhstan, and Belarus. Carter directed military planning during the 1994 crisis over North Korea's nuclear weapons program. In addition, he was responsible for dealing with the establishment of defense and intelligence relationships with former Soviet countries in the wake of the collapse of the Soviet Union and its nuclear arsenal, and was chairman of NATO's High Level Group. He was also responsible for the Counter proliferation Initiative, control of sensitive U.S. exports, and negotiations that led to the deployment of Russian troops as part of the Bosnia Peace Plan Implementation Force.

From April 2009 to October 2011, Carter was Under Secretary of Defense for Acquisition, Technology, and Logistics, with responsibility for DOD's procurement reform and innovation agenda and completion of procurements such as the KC-46 tanker. He also led the development and production of thousands of mine-resistant ambush protected (MRAP) vehicles, and other acquisitions. He instituted "Better Buying Power," seeking smarter and leaner purchasing. From October 2011 to December 2013, Carter was Deputy Secretary of Defense, serving as the DOD's chief operating officer, overseeing the department's annual budget and its three million civilian and military personnel, steering strategy and budget through sequester, and directing the reform of DOD's national security export controls. He was confirmed by Senate voice vote for both positions.

In an April 4, 2013, speech, he affirmed that the 'Shift to Asia' initiative of President Obama was a priority that would not be affected by the budget sequestration in 2013. Carter noted that The Shift to Asia was principally an economic matter with new security implications. India, Australia, and New Zealand were mentioned as forthcoming security partners. His Pentagon arms-control responsibilities included matters involving the START II, ABM, CFE, and other arms-control treaties.

Secretary of Defense

Carter was nominated by President Barack Obama to be the 25th United States secretary of defense on December 5, 2014.

In his nomination hearing before the Senate Armed Services Committee, he said he was "very much inclined" to increase U.S. military aid to Ukraine. Speaking on the Middle East, he said the U.S. must militarily ensure a "lasting defeat" of Islamic State (ISIL) forces in Iraq and Syria. He also opined that the threats posed by Iran were as serious as those posed by the ISIL forces. He said he was not in favor of increasing the rate of prisoner releases from Guantanamo Bay.

Carter was approved unanimously on February 1, 2015, by the Senate Armed Services Committee. He was confirmed by the Senate on February 12 by a vote of 93–5 and sworn in by Vice President Joe Biden on February 17.

In May 2015, Carter warned the People's Republic of China to halt its rapid island-building in the South China Sea.

In October 2015, Carter condemned Russian air strikes against ISIL and other rebel groups in Syria. On October 8, 2015, Carter, speaking at a meeting of NATO defense ministers in Brussels, said he believed Russia would soon start paying the price for its military intervention in Syria in the form of reprisal attacks and casualties.

A controversy arose in December 2015 when it was revealed that Carter had used a personal email account while conducting official business as Secretary of Defense.

In January 2016, at Carter's direction, the Department of Defense opened all military roles to women, overriding a request by the Marine Corps to continue to exempt women from certain positions. In June 2016, Carter announced that transgender individuals would be allowed to join and openly serve in the military.

Other roles
From 1990 to 1993, Carter was chairman of the editorial board of International Security. Previously, he held positions at the Massachusetts Institute of Technology, the Congressional Office of Technology Assessment, and Rockefeller University.

In 1997, Carter and former CIA director John M. Deutch co-chaired the Catastrophic Terrorism Study Group which urged greater attention to terrorism. In 1998, Carter, Deutch, and Philip Zelikow (later executive director of the 9/11 Commission) published an article on "catastrophic terrorism" in Foreign Affairs. From 1998 to 2000, he was deputy to William J. Perry at the North Korea Policy Review and traveled with him to Pyongyang. In 2001–02, he served on the National Academy of Sciences Committee on Science and Technology for Countering Terrorism, and advised on the creation of the Department of Homeland Security. Carter was also co-director of the Preventive Defense Project, which designs and promotes security policies aimed at preventing the emergence of major new threats to the United States.

Carter had been a longtime member of the Defense Science Board and the Defense Policy Board, the principal advisory bodies to the Secretary of Defense. During the Bush administration, he was also a member of Secretary of State Condoleezza Rice's International Security Advisory Board; co-chair of the Senate Foreign Relations Committee's Policy Advisory Group; a consultant to the Defense Science Board; a member of the National Missile Defense White Team, and a member of the National Academy of Sciences Committee on International Security and Arms Control. He had testified frequently before the armed services, foreign relations, and homeland security committees of both houses of Congress.

In addition to his public service, Carter was a senior partner at Global Technology Partners, focused on advising investment firms in technology and defense. He was a consultant to Goldman Sachs and Mitretek Systems on international affairs and technology matters, and spoke frequently to business and policy audiences. Carter served as an independent director on the General Electric board of directors from 2020 until his death.

He was also a member of the boards of directors of the Mitre Corporation and Mitretek Systems and the advisory boards of MIT Lincoln Laboratory and Draper Laboratory. Carter was also a member of the Aspen Strategy Group, the Council on Foreign Relations, the American Physical Society, the International Institute for Strategic Studies, and the National Committee on U.S.-China Relations. Carter was elected a fellow of the American Academy of Arts and Sciences. He was named as a Fellow in the American Physical Society (Forum on Physics & Society) in 2015.

Carter served as an honorary director on the board of directors at the Atlantic Council. In April 2021, Carter joined Tanium Board of Directors. From 2021, he had been a member of the President's Council of Advisors on Science and Technology (PCAST). In 2021, Carter joined Shield Capital's board of Strategic Advisors.

Views on Iran
Carter's views on Iran had been perceived as hawkish. In 2006, he authored a report for the Carnegie Endowment for International Peace advocating use or threat of force to prevent Iran from obtaining nuclear weapons. Carter had supported diplomacy with Iran and written about methods of containing a nuclear-armed Tehran.

Support for military interventions

Carter was a supporter of the 2003 invasion of Iraq, as well as an advocate of "preventative" invasions of North Korea and Iran. In response to increased tension in Ukraine, Carter considered deployment of ground-launched cruise missiles in Europe that could pre-emptively destroy Russian weapons.

Military involvement in presidential elections
In January 2021, Carter, alongside all of the other living former secretaries of defense, published a Washington Post op-ed piece opposing President Donald Trump's summons for military involvement in overturning the 2020 election results, and urging for a peaceful transition of power.

Personal life
Carter was married to Stephanie DeLeeuw Carter. He had been previously married to Clayton Spencer, the eighth president of Bates College, with whom he had two children, Ava and Will.

Carter died from a heart attack at his home in Boston, on October 24, 2022, at age 68.

Awards
Carter received the Ten Outstanding Young Americans award from the United States Junior Chamber in 1987. For his service to national security, Carter was awarded the DOD's highest civilian medal, the Department of Defense Medal for Distinguished Public Service, five times. For critical liaison efforts with the chairman of the Joint Chiefs of Staff and the geographic combatant commanders, he was awarded the Chairman of the Joint Chiefs of Staff Joint Distinguished Civilian Service Award in 2013 and the Defense Intelligence Medal for his contributions to intelligence.

Works
In addition to authoring numerous articles, scientific publications, government studies, and Congressional testimonies, Carter co-edited and co-authored 11 books:

 * MX Missile Basing (1981)
 * Ballistic Missile Defense (1984)
 * Directed Energy Missile Defense in Space (1984)
 * Managing Nuclear Operations (1987)
 * Soviet Nuclear Fission: Control of the Nuclear Arsenal in a Disintegrating Soviet Union (1991)

title: Ash Carter


text:
61 Virginis

61 Virginis (abbreviated 61 Vir) is the Flamsteed designation of a G-type main-sequence star (G7V) slightly less massive than the Sun (which has a hotter G2V spectral type), located 27.8 ly away in the constellation of Virgo. The composition of this star is nearly identical to the Sun.

61 Virginis (G7V) is the first well-established main-sequence star very similar to the Sun with a potential super-Earth, though it was preceded by CoRoT-7 (a borderline orange dwarf).

Description
61 Virginis is a fifth-magnitude G-type main-sequence star with a stellar classification of G7 V. It is faint but visible to the naked eye south and east of the bright star Spica in the zodiac constellation of Virgo. The designation 61 Virginis originated in the star catalogue of English astronomer John Flamsteed, as part of his Historia Coelestis Britannica. An 1835 account of Flamsteed's work by English astronomer Francis Baily noted that the star showed a proper motion. This made the star of interest for parallax studies, and by 1950 a mean annual value of 0.006″ was obtained. The present day result, obtained with data from the Gaia satellite, gives a parallax of 117.17 mas, which corresponds to a physical separation of 27.8 light-years from the Sun.

This star is similar in physical properties to the Sun, with around 95% of the Sun's mass, 98% of the radius, and 85% of the Luminosity. The abundance of elements is also similar to the Sun, with the star having an estimated 95% of the Sun's proportion of elements other than hydrogen and helium. It is older than the Sun at around 6.1–6.6 billion years of age, and is spinning with a leisurely projected rotational velocity of 4 km/s at the equator. On average, there is only a low level of activity in the stellar chromosphere and it is a candidate for being in a Maunder minimum state. But the star was suspected as variable in 1988, and a burst of activity was observed between Julian days [24]54800 (29 November 2008) and 55220 (23 January 2010).

The space velocity components of this star are U = –37.9, V = –35.3 and W = –24.7 km/s. 61 Vir is orbiting through the Milky Way galaxy at a distance of 6.9 kpc from the core, with an eccentricity of 0.15. It is believed to be a member of the disk population.

Planetary system
On 14 December 2009, scientists announced the discovery of three exoplanets with minimum masses between 5 and 25 times that of Earth orbiting 61 Virginis, using the radial velocity method at the Keck and Anglo-Australian Observatories. The three planets all orbit very near the star; when compared to the orbits of the planets in the Solar System, all three would orbit inside that of Venus. The two outer planets likely resemble Uranus and Neptune, while the innermost planet may be a mini-Neptune or a rocky super-Earth.

The outermost of these three planets, 61 Virginis d (also designated HD 115617 d), was initially not detected in the HARPS data as of 2012 until a reanalysis of the data was done in 2023. A 2021 study listed it as a false positive, but in 2023 two published studies further confirmed it based on an additional 10 years of radial velocity data, though with a smaller minimum mass.

Debris disk
The ecliptic of the 61 Virginis system, as inferred from its dust disc, is inclined to the Solar System at 77°. The star itself is probably inclined at 72°.

A survey with the Spitzer Space Telescope revealed an excess of infrared radiation at a wavelength of 160 μm. This indicated the presence of a debris disk in orbit around the star. This disk was resolved at 70 μm. It was then thought to correspond to an inner radius of 96 AU from the star and outer radius at 195 AU; it is now constrained 30 to over 100 AU. The total mass of the disk is 5 × 10−5 the mass of the Earth.

On 27 November 2012, the European Space Agency declared that the debris disc (like that of the Gliese 581 planetary system) has "at least 10 times" as many comets as does the Solar System.

Limits on additional planets
In 1988, a study surmised that 61 Virginis was a "possible variable", but no companions were then found. A subsequent study, over eleven years, also failed to find any companion up to the mass of Jupiter and out to 3 AU.

As of 2012, "planets more massive than Saturn orbiting within 6 AU" were ruled out. The ESA has further ruled out Saturn-mass planets beyond that.

Additional data is needed to confirm the possibility of more sub-Saturn planets between 0.5 and 30 AU from the star. An Earth-mass planet in the star's habitable zone (which would still be too small to detect with current technology) remains possible. As the three 61 Virginis planets are more massive and closer-in than the Sun's terrestrial planets, such an Earth-mass planet would also serve as the system's Mars analogue.

View from 61 Virginis
The Sun is barely visible from the system as a small star close to the much brighter Sirius. Arcturus (magnitude −1.01) is the brightest star of the night sky.

title: 61 Virginis


text:
Talk:Black Dahlia

Last Seen. Please change.
Elizabeth Short was last seen on 14th of January 1947. She was drinking beer with a former Marine called "Bob" and "Red".It was reported in the New York Daily Mirror on 19th January 1947 and is in the online F.B.I. files, section 2 page 38.She stayed at a hotel before she died the hotel is called biltmore hotel in downtown los angelas.Th main suspects were:walter bayley,norman chandler,leslie dionne,joseph A.dumais,mark hansen,geroge hodel,geroge knowlton,Robert.M"red manley.{The Black Dahlia Murder}}January 2023 (UTC).

“Disappeared”.
Elizabeth Short was seen drinking beer with Robert Hunter, a former Marine, in San Diego on 14th January 1947.

This was reported by The New York Daily Mirror on 19th January 1947.

Elizabeth Short did not disappear on the 9th January 1947. She went back to San Diego with Hunter. 2A00:23C6:410F:A001:1C2A:F2CC:7CC0:B62C (talk) 22:52, 9 March 2024 (UTC)

title: Talk:Black Dahlia


text:
Parkhead

Parkhead (Pairkheid) is a district in the East End of Glasgow. Its name comes from a small weaving hamlet at the meeting place of the Great Eastern Road (now the Gallowgate and Tollcross Road) and Westmuir Street. Glasgow's Eastern Necropolis cemetery was laid out in the area in 1847 beside the Gallowgate.

History
The area flourished with the discovery of coal in 1837 and grew into an industrial centre. In 1897 William Beardmore and Company became famous with the production of high grade steel and castings at the local Parkhead Forge, founded about 1837 and extended between 1884 and 1914. After years of decline, the massive plant was closed in 1976, and in 1986 the construction of the first phase of The Forge Shopping Centre began on the site. The shopping centre opened in the autumn of 1988, and in 1994 an indoor market was added adjacent to it. The final element, a retail park, was completed in three stages between 1996 and 2002.

Parkhead Cross is a major road junction which is the meeting point of Gallowgate, Duke Street, Westmuir Street, Tollcross Road and Burgher Street, which together form a turreted Edwardian five-way junction, including several fine buildings making the junction notable, such as the former Glasgow Savings Bank. The junction, which also incorporates the northern termination of the major Springfield Road thoroughfare, can become very busy due to traffic for football games at nearby Celtic Park.

Most of the district's amenities and places of worship are situated within a few blocks of the Cross.

Hospitals
Belvidere Hospital, built on the Belvidere estate which extended from London Road to the River Clyde, originally consisted of wooden huts thrown up rapidly when the city's older fever hospital at Parliamentary Road was overwhelmed by a typhus epidemic in 1870. A self-contained smallpox hospital of five brick pavilions was built from 1874. After this, nineteen pavilions of red-and-white striped brick were set up for the fever hospital. In recent times, with the general closure of infectious disease hospitals, care of elderly people became its main function before closing in 1999.

Parkhead Hospital, which opened on 12th November 1988, was said to be the only new psychiatric hospital to be built in Scotland in the 20th century. (However, some 18th and 19th century institutions did move to new buildings during the 20th century.) It was built on part of the old forge land, next to the Parkhead Health Centre, and replaced the psychiatric and psycho-geriatric admission wards of both Duke Street Hospital (formerly known as the Eastern District Hospital) and Gartloch Hospital – both units moved into the new hospital in 1988 on the day of a Rangers-Celtic match at the nearby Celtic Park. The hospital closed in 2018, with the intention of building a new health facility on the site.

Libraries
Parkhead also has one of Glasgow's original Carnegie libraries, deftly designed in the Edwardian Baroque style by James Robert Rhind.

Celtic Park and Barrowfield
Parkhead is perhaps best known as the home of Celtic Football Club and their stadium Celtic Park, which opened in 1892 after the club moved across the road from their old ground, which they had been playing on for their first three years. A journalist covering the event reported that it was like "moving from the graveyard to paradise", referencing the proximity of the adjacent cemetery, hence the nickname "Paradise". Celtic Park is located at 95 Kerrydale Street, just off London Road. The stadium itself is commonly referred to as 'Parkhead' because of its location. The stadium was substantially rebuilt between 1994 and 1998 and is Scotland's largest football stadium by seating capacity.

From the early 1960s, Celtic conducted most of their training routines at a facility on the periphery of Parkhead named Barrowfield, east of Celtic Park (it is not located in the Barrowfield residential area which lies to the west of the stadium toward Bridgeton). By 2005, those facilities were seen as antiquated, particularly in comparison to those of their Old Firm rivals Rangers at Auchenhowie. Celtic considered building new facilities at their site in Barrowfield, but instead decided to develop the Lennoxtown training centre outside the city. Today there are still football pitches on the land as well as a large Celtic social club; the Celtic first team temporarily resumed training at Barrowfield in November 2011, after a spate of training ground injuries led manager Neil Lennon to fear that the Lennoxtown pitches were responsible. In 2019, Celtic announced plans to redevelop Barrowfield for use by their youth academy and women's team, including an indoor pitch and a matchday venue, augmenting the Lennoxtown base which would continue to be used by the first team squad and strengthening their connection to their roots in the East End of Glasgow.

Other
Prior to its dissolution, Parkhead FC was one of the most successful Junior sides of the first half of the 20th century. Two other strong teams of the time, Bridgeton Waverley and Strathclyde also had their grounds in close proximity (New Barrowfield and Springfield Park respectively); none of the three clubs survived into the late 20th century. Parkhead's ground Helenslea Park is now a landscaped public park.

There are also two bowling clubs and a derelict sports ground (Helenvale Park, formerly used by the Glasgow Corporation Transport department which had a large bus and tram depot nearby)  in the vicinity – Crownpoint Sports Complex, a replacement modern outdoor athletics track, is located beyond the western border of the district adjacent to St Mungo's Academy. After the 2014 Commonwealth Games was held in Glasgow, Parkhead now has international-class sporting facilities within walking distance: the Commonwealth Arena and Sir Chris Hoy Velodrome are located in nearby Dalmarnock.

Rail

 * Parkhead North railway station
 * Parkhead Stadium railway station

Famous Residents

 * John Scott Russell, engineer
 * Jim Cairney, footballer
 * John Cairney, writer

title: Parkhead


text:
Talk:Twistor theory

complex spaces
Unless I am missing something, I thought complex spaces don't have metric signatures, unlike real spaces. Phys 06:28, 1 Dec 2004 (UTC)

I'm a physics student at UCLA, I've only read about Twistors but from what Roger Penrose describes it as it is "Higher dimensional spinors" (from his tome "Road to Reality"). So, rather than the conventional 2 dimensional complex vector space, there is instead a 4 dimensional complex vector space. This is, of course, from an undergrad's understanding, so I may have missed the boat completely!

Further the twistor depends on the spinor momentum $$\pi\,_{A'}$$ where it satisfies

$$ p^{ \alpha\, } = \bar{ \pi\,^{ A } }\pi\,^{ A' } $$

the noncontracted multiplication of it and its complex conjugate is equal to the four-momentum. These, however, are the last two coordinates of the Twistor.

The first two are related to the angular momentum, but can be calculated from the momentum components of the twistor.

Twistors are concerned, first of all, with incidence (in the geometric sense of the word). That is to say, with (say) a light cone, if an event lies within the light cone it is in incidence with the light cone. The coordinates of the event in incidence with the twistor is $$r^{ A A' }$$. That is

$$ r^{ A A' } = \begin{bmatrix} t+z & x-iy \\ x+iy & t-z \end{bmatrix} $$

in spinor form. The relation of the angular momentum components $$\omega\,^{ A }$$ to the linear momentum components $$\pi\,_{A'}$$ are

$$ \omega\,^{ A } = i r^{ A A' } \pi\,_{A'} $$

Thus a spinor $$Z^{\alpha \,} = (\omega \,^{A}, \pi \,^{A'} )$$. The norm of the twistor has a unique relation to the helicity of the particle in question with the equation

$$ s = \frac{ 1 }{ 2 } \bar{Z_{ \alpha }}Z^{ \alpha }\,$$

where $$ s $$ is helicity. That's the primer. Cheers! - Pablo.

sentence
Can someone tell me why this is "For some time there was hope that the twistor theory may be the right approach towards solving quantum gravity, but this is now considered unlikely."?

Thanks

Alan ( alan_stafford@btinternet.com )

 * Originates from the first edit of this page by the User:Tracian on 4 July 2003. http://en.wikipedia.org/w/index.php?title=Twistor_theory&oldid=1111051

 * I think he means why is twistor theory no longer perceived as a great hope for approaching quantum gravity...not why that section is in the text. Well, for one it works primarily with special relativity rather than general relativity...twistors could be seen more as a quantization of the light cone rather than a quantization of gravity itself. It does, nonetheless, give insight into making events "fuzzy" rather than null vectors (the paths light takes). I recall reading from a monograph from the late 80s or early 90s that Christopher Isham thought Twistors would be more of a "last resort" rather than a "frontal assault" for quantum gravity, so "when all else fails" we can still fall back on it! The reason for his stance, I think, was the promise of Ashtekar variables in the canonical approach to quantum gravity appeared to be superior to the promise of the twistor programme. That is not to say however that twistors are useless, they are actually rather interesting things...it's just that there are other approaches which appear to be superior at the moment.

User:Tracian on 4 July 2003 is obviously an idiot. —Preceding unsigned comment added by 81.98.169.252 (talk) 06:34, 13 August 2009 (UTC)

music
How does the link "Music based on twistor theory" have anything to do with Twistor theory - besides the band's founder (Mr. Hogan) studying Twistor Theory at a university and adopting the name "TWISTOR" for his DJing business? There may be some valid relationship between Twistor Theory and Mr. Hogan, but there seems to be no basis in Twistor theory within the music itself. Davidl9999 19:38, 29 October 2007 (UTC)

Too short, too technical, insufficient motivation
This entry is too short, given the importance of its topic, and too technical for Wikipedia. There should be more historical and motivational material. The technical parts should be written at the level of The Road to Reality.

Just where does twistor theory propose to take fundamental theoretical physics? Is it a candidate theory of everything? Can it integrate general relativity and quantum theory? More should be said on why Mr String Theory Incarnate, Ed Witten decided to draw on twistor theory early this decade. Andrew Hodges's website conveys a lot of recent excitement about twistor theory. Could some bits of the info underlying Hodges's enthusiasm be added to this entry? Peter Woit and Lee Smolin have written recent books arguing that string theory is not living up to its former promise. What do they think of twistor theory?123.255.26.213 (talk) 22:59, 8 April 2009 (UTC)

Comment
add the definition of a null ray (not transformers of course) which is given by Juan Martín Maldacena — Preceding unsigned comment added by 2a02:587:410a:c500:8d92:8418:8856:6cf1 (talk) 20:44, 2 December 2016 (UTC)

External links modified (January 2018)
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Utterly (and deliberately?) useless article
The “overview” is literally useless for understanding what this is. Which is, you know, the whole point of the article. Only someone who alteady onows better than even the article author himself, can decode the way those lines of code words are carefully put together to maximize the stumpedness, for the purpose of making the author feel big and smart. I noticed, this is a common pattern in Wikipedia’s mathematics and physics articles. But at this point, this is actually more harmful than not having the article at all. As it leads people away from actual explanations and makes them think this is too hard for them. (It certainly is not! It is just badly explained. Richard Feynman, 3blue1brown, ScienceClic, Sabine Hossenfelder or Harald Lesch could explain it to laypeople just fine.)

What can we do, to fix this situation? Clearly, Wikipedia is broken here. INobody intended this. It needs a change at Wikipedia’s core.

— 2A02:3035:60F:BB77:6E29:63C:7557:1A1F (talk) 20:49, 27 May 2024 (UTC)

title: Talk:Twistor theory


text: User talk:12.221.104.250

title: User talk:12.221.104.250


text:
Island spotted skunk

The island spotted skunk (Spilogale gracilis amphiala) is an insular endemic carnivore and a subspecies of the western spotted skunk (Spilogale gracilis). Little is known about their exact variations from the mainland spotted skunk and variations between locations, resolution of which awaits further genetic and morphologic evaluation. The skunk is only currently found on two islands off the southern coast of California (Santa Cruz Island, and Santa Rosa Island, where its occurrence is rare). Its presence has been recorded on San Miguel Island, but it has since been declared extinct in that area. The Channel Island skunk is one of two terrestrial carnivores on the islands, the other being the island fox. It is designated as a species of special concern by the state of California.

Range
The island spotted skunk is endemic to the Channel Islands off the coast of Southern California. It currently is only found on Santa Rosa and Santa Cruz islands where it is widely distributed. There are previous reports of this taxon living on San Miguel island as well. Record of its inhabitance on San Miguel island ceased after the late nineteen hundreds and it is believed to be extirpated from this region. As of 2011, there were reportedly 3,000 Island Spotted Skunks on Santa Rosa island alone. However, after the recovery of the island fox in the mid-2000s, skunk sightings have become rare once again.

Habitat
The island spotted skunk exhibits habitat preferences similar to those of the mainland species. Its dens have been found in various types of locations including, but not limited to, beneath shrubs, open grasslands, rocky slopes, and beneath the roots of large trees. Difference in habitat preference varied slightly between the two islands. Skunks on Santa Rosa mainly being found in rocky canyon slopes, cactus patches, chaparral, coastal sage scrub, open woodland areas, and riparian habitats along streams. On Santa Cruz Island, skunks are found to prefer chaparral-grasslands, open grasslands, fennel-grasslands, and ravines. Skunks were also found to make dens beneath human dwellings and buildings.

Description
Island spotted skunks show little morphological variation between islands, aside from the skunks found on Santa Rosa Island being slightly longer than those found on Santa Cruz Island. It is distinguished from mainland spotted skunks by its shorter tail with less white ventral coloration (45% white compared to 55% white), slightly larger size, broader skull, and proportionately less white and more black in pelage color. They also tend to have smoother, glossier fur than the mainland variation. It can be identified by an arrangement of white stripes on black fur, running vertically down the back. There are 4 to 6 stripes and they are usually broken up to give the skunk its “spotted” appearance. The abdomen is white and there is also a small white triangle on the forehead. On average, males tend to be about 23% larger than females.

Diet
Island skunks exhibit similar diets to those of mainland skunks. They are carnivorous, and unlike their mainland relatives who mostly consume insects, feed primarily on Island Deer Mice. Analysis of skunks on Santa Cruz Island showed consumption of insects and occasional lizards in addition to the Deer Mice. Insects consisted mainly of Jerusalem Crickets, along with grasshoppers, crickets, beetles, caterpillars, ear wigs, and ants. Seasonally available fruits and berries are also part of the skunks diet, including grapes, summer holly, stems, and cactus fruits. The Channel Island skunk is one of two terrestrial carnivores living on the island, the other being the Island Fox. The two species are in competition for resources and the Island Skunk's diet became more omnivorous in the 1990s due to a decrease in Island Fox populations. In recent years, skunks have been observed expanding their carnivorous diets to include seabirds. The birds typically nest in sea caves and this recent expansion has been attributed to an increase in population following the decline of foxes.

Activity
Skunks are nocturnal animals. Activity begins at dusk, peaks during early evening, and continues until dawn. Individuals use several dens distributed throughout their home range. Females have been known to simultaneously share a den, while males are more likely to share the same den sequentially.

Reproduction
Channel Island skunks have similar mating behaviors to mainland skunks and exhibit the same delayed implantation. Mating occurs throughout the months of September and October, followed by delayed implantation, and a 210- to 310-day gestation period. They typically give birth during the months of April and May to anywhere from 2 to 6 young.

Conservation status
The Island spotted skunk is listed as a species of special concern by the state of California. This is because populations were thought to be low due to rare sightings which restrict the ability to study it, and therefore little was known about the subspecies. Although it was thought to be more abundant in the past (early 20th century), it is now listed as a Class II status of concern due to its restricted distribution. The skunk's small population size can be attributed to several factors. The first of which being loss and degradation of habitat resulting from over grazing by domestic livestock (cattle and horses) and feral nonnative herbivores (sheep, deer, elk). Another possible threat to the skunk is introduction of diseases by domestic cats and dogs brought to the island as pets. The species occurs widely on Santa Cruz island, but is uncommon to rare, and is more common on Santa Rosa island. During the 1990s, the island skunk population saw an increase due to reduced competition from their natural competitor, the island fox. The fox's population decreased dramatically following the colonization of the Channel Islands by the golden eagle.

Conservation efforts
Action has been taken to try and increase skunk populations on the islands. In the early 1980s 38,000 feral sheep were removed from Santa Cruz Island and cattle ranching operations terminated in 1988. Despite these efforts, feral pigs continue to pose a great threat to skunk populations as their rooting destroys skunk dens. Skunks are specialized in their resources and therefore sensitive to competition with feral pigs for invertebrate foods. The future of skunk populations on Santa Rosa Island is expected to be positive due to the eradication of feral pigs in the '80s.

Updated status
The status of skunks on Santa Cruz Island was reevaluated in 1998, six years after previous research done in 1992, which helped to determine the Island skunks as rare or of special concern. Across the six-year period a sudden increase in skunk populations was observed. This was attributed to several possible factors such as high rainfall in 1998 after many years of drought, which was thought to have stimulated plant growth. This could have in turn, stimulated reproduction because of the delayed implantation exhibited by the skunks which could allow them to increase fecundity during good years. Additionally, the skunks could be responding to recovery efforts on the island. The skunks most direct competitor for resources, the island fox, had also been exhibiting a population decline which would result in less competition for the resource specific island skunk. Skunk populations showed a remarkable increase over a ten-year period, and in 2011 approximately 3,000 skunks were marked and counted during population monitoring. As fox populations recovered in the 2000s and 2010s, skunk captures became rare once again.

Recent genetic testing
Recent genetic research was done on Channel Island skunks to determine genetic variation in skunks between islands. Morphologically skunks on both islands do not seem to vary whatsoever, except that the skunks on Santa Rosa Island are slightly longer than those on Santa Cruz Island. The study found that genetic variation between the two island species was not consistent with the morphological variation and was much greater than that of the mainland species. This conclusion has led researchers to hypothesize that spotted skunks were brought to the islands either by rafting or intentionally by Native Americans. The genetic variation between mainland skunks and those on the islands is enough to cause researchers to propose that the taxonomic classification of the skunks as S. g. amphiala be reconsidered, and that each island population be considered a separate subspecies or even a new species separate from the mainland one.

title: Island spotted skunk