SUMMARY / RELATED TOPICS

Lightning

Lightning is a occurring electrostatic discharge during which two electrically charged regions in the atmosphere or ground temporarily equalize themselves, causing the instantaneous release of as much as one gigajoule of energy. This discharge may produce a wide range of electromagnetic radiation, from hot plasma created by the rapid movement of electrons to brilliant flashes of visible light in the form of black-body radiation. Lightning causes thunder, a sound from the shock wave which develops as gases in the vicinity of the discharge experience a sudden increase in pressure. Lightning occurs during thunderstorms and other types of energetic weather systems, but volcanic lightning can occur during volcanic eruptions; the three main kinds of lightning are distinguished by where they occur: either inside a single thundercloud, between two different clouds, or between a cloud and the ground. Many other observational variants are recognized, including "heat lightning", which can be seen from a great distance but not heard.

Humans have deified lightning for millennia, lightning-inspired expressions like "bolt from the blue", "to be struck by lightning", "lightning never strikes twice" and "blitzkrieg" are in common usage. In some languages, the notion of "love at first sight" translates as "lightning strike"; the details of the charging process are still being studied by scientists, but there is general agreement on some of the basic concepts of thunderstorm electrification. The main charging area in a thunderstorm occurs in the central part of the storm where air is moving upward and temperatures range from −15 to −25 °C. At that place, the combination of temperature and rapid upward air movement produces a mixture of super-cooled cloud droplets, small ice crystals, graupel; the updraft carries the super-cooled cloud droplets and small ice crystals upward. At the same time, the graupel, larger and denser, tends to fall or be suspended in the rising air; the differences in the movement of the precipitation cause collisions to occur.

When the rising ice crystals collide with graupel, the ice crystals become positively charged and the graupel becomes negatively charged. The updraft carries; the larger and denser graupel is either suspended in the middle of the thunderstorm cloud or falls toward the lower part of the storm. The result is that the upper part of the thunderstorm cloud becomes positively charged while the middle to lower part of the thunderstorm cloud becomes negatively charged; the upward motions within the storm and winds at higher levels in the atmosphere tend to cause the small ice crystals in the upper part of the thunderstorm cloud to spread out horizontally some distance from thunderstorm cloud base. This part of the thunderstorm cloud is called the anvil. While this is the main charging process for the thunderstorm cloud, some of these charges can be redistributed by air movements within the storm. In addition, there is a small but important positive charge buildup near the bottom of the thunderstorm cloud due to the precipitation and warmer temperatures.

A typical cloud-to-ground lightning flash culminates in the formation of an electrically conducting plasma channel through the air in excess of 5 km tall, from within the cloud to the ground's surface. The actual discharge is the final stage of a complex process. At its peak, a typical thunderstorm produces three or more strikes to the Earth per minute. Lightning occurs when warm air is mixed with colder air masses, resulting in atmospheric disturbances necessary for polarizing the atmosphere. However, it can occur during dust storms, forest fires, volcanic eruptions, in the cold of winter, where the lightning is known as thundersnow. Hurricanes generate some lightning in the rainbands as much as 160 km from the center; the science of lightning is called fulminology, the fear of lightning is called astraphobia. Lightning is not distributed evenly around Earth. On Earth, the lightning frequency is 44 times per second, or nearly 1.4 billion flashes per year and the average duration is 0.2 seconds made up from a number of much shorter flashes of around 60 to 70 microseconds.

Many factors affect the frequency, distribution and physical properties of a typical lightning flash in a particular region of the world. These factors include ground elevation, prevailing wind currents, relative humidity, proximity to warm and cold bodies of water, etc. To a certain degree, the ratio between IC, CC and CG lightning may vary by season in middle latitudes; because human beings are terrestrial and most of their possessions are on the Earth where lightning can damage or destroy them, CG lightning is the most studied and best understood of the three types though IC and CC are more common types of lightning. Lightning's relative unpredictability limits a complete explanation of how or why it occurs after hundreds of years of scientific investigation. About 70 % of lightning occurs over land in the tropics; this occurs from both the mixture of warmer and colder air masses, as well as differences in moisture concentrations, it happens at the boundaries between them. The flow of warm ocean current

Dudi Amsalem

David "Dudi" Amsalem, is an Israeli politician. He serves as a member of the Knesset for Likud and ascurrently Minister of Communications. David Amsalem was raised in Jerusalem, his parents and Sultana Amsalem, were immigrants from Morocco. Amsalem was educated at Etzion. During his IDF national service he was a tank commander in the Armored Corps, he obtained a bachelor's degree in Economics and Business Administration from Bar-Ilan University. Amsalem is a widower with two daughters, he is a resident of Ma'ale Adumim. A member of the Likud, he became chairman of the party's Jerusalem branch, he was placed 42nd on the joint Likud Yisrael Beiteinu list for the 2013 Knesset elections, but with the alliance winning only 31 seats, he did not become a Knesset member. Prior to the 2015 Knesset elections he was placed 21st on the party's list, a slot reserved for a candidate from the Jerusalem area, he was elected to the Knesset. In December 2017 he was appointed whip of the governing coalition. After being re-elected in the April 2019 elections, he was appointed as Minister of Communications on 1 July.

Dudi Amsalem on the Knesset website

Leucothea

In Greek mythology, Leucothea or Leucothoë was one of the aspects under which an ancient sea goddess was recognized, in this case as a transformed nymph. In the more familiar variant, the daughter of Cadmus, sister of Semele, queen of Athamas, became a goddess after Hera drove her insane as a punishment for caring for the newborn Dionysus, she leapt into the sea with her son Melicertes in her arms, out of pity, the Hellenes asserted, the Olympian gods turned them both into sea-gods, transforming Melicertes into Palaemon, the patron of the Isthmian games, Ino into Leucothea. In the version sited at Rhodes, a much earlier mythic level is reflected in the genealogy: there, the woman who plunged into the sea and became Leucothea was Halia whose parents were from the ancient generation and Pontus or Uranus, she was a local one of the aboriginal Telchines of the island. Halia bore him Rhodos and six sons, thus the Rhodians traced their mythic descent from the Sun god Helios. In the Odyssey, Leucothea makes a dramatic appearance as a gannet who tells the shipwrecked Odysseus to discard his cloak and raft and offers him a veil to wind round himself to save his life and reach land.

Homer makes her the transfiguration of Ino. In Laconia, she has a sanctuary; this is her form of the oracle. Leucothea is mentioned by John Milton in the Paradise Lost scene where archangel Michael descends to Adam and Eve to declare that they must no longer abide in Paradise:Leucothea is mentioned by Robert Graves in The White Goddess. In Ezra Pound's Cantos, she is one of the goddess figures who comes to the poet's aid in Section: Rock-Drill, she is introduced in Canto 91 as "Cadmus's daughter":She returns in Cantos 93 and 95, reappears at the beginning of Canto 96, the first of the Thrones section. Leucothea appears twice in Dialoghi con Leucò by Cesare Pavese. Leucothoé was the first work by the Irish playwright Isaac Bickerstaffe published in 1756. Leucothea becomes a metaphor, in Marcel Proust's In the Shadow of Young Girls in Flower, for the mist that covers a young man's gaze when looking on the beauty of young women: "...a cloud that had re-formed a few days once I had met them, muting the glow of their loveliness passing between them and my eyes, which saw them now dimmed, as through a gentle haze, reminiscent of Virgil's Leucothea."

Leukothea is a poem by Keith Douglas. Burkert, Walter. Greek Religion, 1985. Graves, Robert; the Greek Myths, 1955. Kerenyi, Karl; the Gods of the Greeks, 1951. Russo, Sergio. Quando il mare profuma di ambrosia. Leucotea e Palemone nel Mediterraneo, 2017