Saskatchewan is a prairie and boreal province in western Canada, the only province without a natural border. It has an area of 651,900 square kilometres, nearly 10 percent of, fresh water, composed of rivers and the province's 100,000 lakes. Saskatchewan is bordered on the west by Alberta, on the north by the Northwest Territories, on the east by Manitoba, to the northeast by Nunavut, on the south by the U. S. states of North Dakota. As of late 2018, Saskatchewan's population was estimated at 1,165,903. Residents live in the southern prairie half of the province, while the northern boreal half is forested and sparsely populated. Of the total population half live in the province's largest city Saskatoon, or the provincial capital Regina. Other notable cities include Prince Albert, Moose Jaw, Swift Current, North Battleford and the border city Lloydminster. Saskatchewan is a landlocked province with large distances to moderating bodies of waters; as a result, its climate is continental, rendering severe winters throughout the province.
Southern areas have warm or hot summers. Midale and Yellow Grass near the U. S. border are tied for the highest recorded temperatures in Canada with 45 °C observed at both locations on July 5, 1937. In winter, temperatures below −45 °C are possible in the south during extreme cold snaps. Saskatchewan has been inhabited for thousands of years by various indigenous groups, first explored by Europeans in 1690 and settled in 1774, it became a province in 1905, carved out from the vast North-West Territories, which had until included most of the Canadian Prairies. In the early 20th century the province became known as a stronghold for Canadian social democracy; the province's economy is based on agriculture and energy. Saskatchewan's current lieutenant governor is the current premier is Scott Moe. In 1992, the federal and provincial governments signed a historic land claim agreement with First Nations in Saskatchewan; the First Nations received compensation and were permitted to buy land on the open market for the bands.
Some First Nations have used their settlement to invest in urban areas, including Saskatoon. Its name derived from the Saskatchewan River; the river was known as kisiskāciwani-sīpiy in the Cree language. As Saskatchewan's borders follow the geographic coordinates of longitude and latitude, the province is a quadrilateral, or a shape with four sides. However, the 49th parallel boundary and the 60th northern border appear curved on globes and many maps. Additionally, the eastern boundary of the province is crooked rather than following a line of longitude, as correction lines were devised by surveyors prior to the homestead program. Saskatchewan is part of the Western Provinces and is bounded on the west by Alberta, on the north by the Northwest Territories, on the north-east by Nunavut, on the east by Manitoba, on the south by the U. S. states of North Dakota. Saskatchewan has the distinction of being the only Canadian province for which no borders correspond to physical geographic features. Along with Alberta, Saskatchewan is one of only two land-locked provinces.
The overwhelming majority of Saskatchewan's population is located in the southern third of the province, south of the 53rd parallel. Saskatchewan contains two major natural regions: the Boreal Forest in the north and the Prairies in the south, they are separated by an aspen parkland transition zone near the North Saskatchewan River on the western side of the province, near to south of the Saskatchewan River on the eastern side. Northern Saskatchewan is covered by forest except for the Lake Athabasca Sand Dunes, the largest active sand dunes in the world north of 58°, adjacent to the southern shore of Lake Athabasca. Southern Saskatchewan contains another area with sand dunes known as the "Great Sand Hills" covering over 300 square kilometres; the Cypress Hills, located in the southwestern corner of Saskatchewan and Killdeer Badlands, are areas of the province that were unglaciated during the last glaciation period, the Wisconsin glaciation. The province's highest point, at 1,392 metres, is located in the Cypress Hills less than 2 km from the provincial boundary with Alberta.
The lowest point is the shore of Lake Athabasca, at 213 metres. The province has 14 major drainage basins made up of various rivers and watersheds draining into the Arctic Ocean, Hudson Bay and the Gulf of Mexico. Saskatchewan receives more hours of sunshine than any other Canadian province; the province lies far from any significant body of water. This fact, combined with its northerly latitude, gives it a warm summer, corresponding to its humid continental climate in the central and most of the eastern parts of the province, as well as the Cypress Hills. Drought can affect agricultural areas during no precipitation at all; the northern parts of Saskatchewan – from about La Ronge northward – have a subarctic climate with a shorter summer season. Summers can get hot, sometimes above 38 °C during the day, with humidity decreasing from northeast to southwest. Warm southern winds blow from the plains and intermontane regions of
Biggar is a town in central Saskatchewan, Canada. It is located on Highway 14, 93 kilometres west of the province's most populous city. Biggar has become well known for its unusual town slogan, an Olympic athlete, a world-record deer; the town was featured on American morning newsmagazine The Today Show in February 2010 as part of an ongoing Canadian-oriented segment during the 2010 Winter Olympics. Biggar was incorporated as a village in 1909, it was named after William Hodgins Biggar, general counsel of the Grand Trunk Pacific railway which had come through the area in 1908. The Grand Trunk Pacific Railway made Biggar a divisional point on its line, building a large station and roundhouse; the population grew. In 1911 Biggar was incorporated as a town. Settlement continued and the population increased to greater than 2,000 by the mid-1920s, peaking at 2,755 in 1966. According to the 2011 census, Biggar is now home to 2,161 people; the town is known for its slogan "New York is big, but this is Biggar."
It was created in 1914 by a survey crew. According to The Biggar Museum and Gallery, the graffiti remained unchanged until 1954 when the slogan was adopted; the Biggar railway station was constructed in 1909-1910 and is serviced by Via Rail with The Canadian serving the station up to three times per week. Biggar's prosperity was directly tied to the railway for many years. Up to 500 local people were at one time employed by Canadian National Railway, which took over the Grand Trunk Pacific Railway; that number has now dropped to under 200. As the railway industry has decreased, Biggar has shifted its economy to agriculture and related industries. Biggar is home to a large barley processing plant; the malthouse has an annual capacity of 220,000 metric tonnes. Malt is a primary ingredient in whisky. Prairie Malt employs 70 full-time employees, it creates significant spin-off employment among local trucking firms such as Biggar Transport, with a fleet of over 50 trucks. The Town of Biggar lists more than 150 services on its website.
These include a manufacturer of petroleum and hazardous material containment tanks, a sodium sulphate plant, a large greenhouse and a variety of financial and health services. Two school divisions operate in Biggar; the public school is Biggar Central 2000, a kindergarten to grade twelve school a part of Sun West School Division. Greater Saskatoon Catholic Schools operates St. Gabriel School, a Catholic kindergarten to grade nine school. Great Plains College offers post-secondary certificates and diplomas in nursing, emergency medical technician and truck driving. Biggar's original classroom was on the second floor of the Biggar Hotel while Biggar Public School was being built. Biggar Public School was built in 1910, was demolished in 1962. Thornton school was built in 1924, demolished in 1972. Biggar elected Major James Coldwell, the leader of the Co-operative Commonwealth Federation, as their Member of Parliament from 1935–58, he was noted as the person that fought for and won old-age pensions, as well as other social democratic reforms in both the William Lyon Mackenzie-King and Louis St. Laurent governments.
Biggar is the hometown of Sandra Schmirler, a 1998 Olympic gold medalist and three-time world champion in women's curling. Schmirler died in 2000 at the age of 36 of cancer, her funeral was broadcast nationally by CBC TSN, a first for a Canadian athlete. Biggar honoured Schmirler's contributions to sport and her hometown by constructing the Sandra Schmirler Olympic Gold Park, which houses a gazebo, playground and wall of fame. Longtime Edmonton Eskimos kicker Dave Cutler was born in Biggar; the town is home to the world-famous "Hanson Buck." Milo Hanson is a Biggar-area farmer and hunter who in 1993 shot a white-tailed deer, awarded the Boone and Crockett Club world's record. Hanson reported that after the award was made public, he received hundreds of calls from journalists and artists wanting to tell the story, his record remains unbeaten. Biggar's current mayor is Ray Sadler; the Town of Biggar is located within the Rural Municipality of Biggar #347. Provincially, Biggar is represented by MLA Randy Weekes of the Saskatchewan Party.
Federally the town is within the riding of Saskatoon—Rosetown—Biggar, whose current MP is Kelly Block of the Conservative Party of Canada. Biggar experiences a humid continental; the highest temperature recorded in Biggar was 40.0 °C on 4 July 1937, 24 June 1941, 6 August 1949. The coldest temperature recorded was −46.7 °C on 16 February 1936. List of communities in Saskatchewan List of towns in Saskatchewan Official Town Website Encyclopedia of Saskatchewan Biggar Encyclopaedia
Halley's Comet or Comet Halley designated 1P/Halley, is a short-period comet visible from Earth every 75–76 years. Halley last appeared in the inner parts of the Solar System in 1986 and will next appear in mid-2061. Halley's returns to the inner Solar System have been observed and recorded by astronomers since at least 240 BC. Clear records of the comet's appearances were made by Chinese and medieval European chroniclers, but were not recognized as reappearances of the same object at the time; the comet's periodicity was first determined in 1705 by English astronomer Edmond Halley, after whom it is now named. During its 1986 apparition, Halley's Comet became the first comet to be observed in detail by spacecraft, providing the first observational data on the structure of a comet nucleus and the mechanism of coma and tail formation; these observations supported a number of longstanding hypotheses about comet construction Fred Whipple's "dirty snowball" model, which predicted that Halley would be composed of a mixture of volatile ices—such as water, carbon dioxide, ammonia—and dust.
The missions provided data that reformed and reconfigured these ideas. Comet Halley is pronounced, rhyming with valley, or, rhyming with daily. Colin Ronan, one of Edmond Halley's biographers, preferred. Spellings of Halley's name during his lifetime included Hailey, Hayley, Halley and Hawly, so its contemporary pronunciation is uncertain, but contemporary individuals with this last name appear to prefer the version that rhymes with "valley". Halley was the first comet to be recognized as periodic; until the Renaissance, the philosophical consensus on the nature of comets, promoted by Aristotle, was that they were disturbances in Earth's atmosphere. This idea was disproved in 1577 by Tycho Brahe, who used parallax measurements to show that comets must lie beyond the Moon. Many were still unconvinced that comets orbited the Sun, assumed instead that they must follow straight paths through the Solar System. In 1687, Sir Isaac Newton published his Philosophiæ Naturalis Principia Mathematica, in which he outlined his laws of gravity and motion.
His work on comets was decidedly incomplete. Although he had suspected that two comets that had appeared in succession in 1680 and 1681 were the same comet before and after passing behind the Sun, he was unable to reconcile comets into his model, it was Newton's friend and publisher, Edmond Halley, who, in his 1705 Synopsis of the Astronomy of Comets, used Newton's new laws to calculate the gravitational effects of Jupiter and Saturn on cometary orbits. Having compiled a list of 24 comet observations, he calculated that the orbital elements of a second comet that had appeared in 1682 were nearly the same as those of two comets that had appeared in 1531 and 1607. Halley thus concluded that all three comets were, in fact, the same object returning about every 76 years, a period that has since been found to vary between 74–79 years. After a rough estimate of the perturbations the comet would sustain from the gravitational attraction of the planets, he predicted its return for 1758. While he had observed the comet around perihelion in September 1682, Halley died in 1742 before he could observe its predicted return.
Halley's prediction of the comet's return proved to be correct, although it was not seen until 25 December 1758, by Johann Georg Palitzsch, a German farmer and amateur astronomer. It did not pass through its perihelion until 13 March 1759, the attraction of Jupiter and Saturn having caused a retardation of 618 days; this effect was computed prior to its return by a team of three French mathematicians, Alexis Clairaut, Joseph Lalande, Nicole-Reine Lepaute. The confirmation of the comet's return was the first time anything other than planets had been shown to orbit the Sun, it was one of the earliest successful tests of Newtonian physics, a clear demonstration of its explanatory power. The comet was first named in Halley's honour by French astronomer Nicolas-Louis de Lacaille in 1759; some scholars have proposed that first-century Mesopotamian astronomers had recognized Halley's Comet as periodic. This theory notes a passage in the Bavli Talmud that refers to "a star which appears once in seventy years that makes the captains of the ships err."Researchers in 1981 attempting to calculate the past orbits of Halley by numerical integration starting from accurate observations in the seventeenth and eighteenth centuries could not produce accurate results further back than 837 due to a close approach to Earth in that year.
It was necessary to use ancient Chinese comet observations to constrain their calculations. Halley's orbital period has varied between 74–79 years since 240 BC, its orbit around the Sun is elliptical, with an orbital eccentricity of 0.967. The perihelion, the point in the comet's orbit when it is nearest the Sun, is just 0.6 AU. This is between the orbits of Venus, its aphelion, or farthest distance from the Sun, is 35 AU. Unusual for an object in the Solar System, Halley's orbit is retrograde; the orbit is inclined by 18 ° with much of it lying south of the ecliptic. Due to the
Astrology is a pseudoscience that claims to divine information about human affairs and terrestrial events by studying the movements and relative positions of celestial objects. Astrology has been dated to at least the 2nd millennium BCE, has its roots in calendrical systems used to predict seasonal shifts and to interpret celestial cycles as signs of divine communications. Many cultures have attached importance to astronomical events, some—such as the Hindus and the Maya—developed elaborate systems for predicting terrestrial events from celestial observations. Western astrology, one of the oldest astrological systems still in use, can trace its roots to 19th–17th century BCE Mesopotamia, from which it spread to Ancient Greece, the Arab world and Central and Western Europe. Contemporary Western astrology is associated with systems of horoscopes that purport to explain aspects of a person's personality and predict significant events in their lives based on the positions of celestial objects.
Throughout most of its history, astrology was considered a scholarly tradition and was common in academic circles in close relation with astronomy, alchemy and medicine. It was present in political circles and is mentioned in various works of literature, from Dante Alighieri and Geoffrey Chaucer to William Shakespeare, Lope de Vega, Calderón de la Barca. Following the end of the 19th century and the wide-scale adoption of the scientific method, astrology has been challenged on both theoretical and experimental grounds, has been shown to have no scientific validity or explanatory power. Astrology thus lost its academic and theoretical standing, common belief in it has declined. While polls have demonstrated that one quarter of American and Canadian people say they continue to believe that star and planet positions affect their lives, astrology is now recognized as a pseudoscience—a belief, incorrectly presented as scientific; the word astrology comes from the early Latin word astrologia, which derives from the Greek ἀστρολογία—from ἄστρον astron and -λογία -logia.
Astrologia passed into meaning'star-divination' with astronomia used for the scientific term. Many cultures have attached importance to astronomical events, the Indians and Maya developed elaborate systems for predicting terrestrial events from celestial observations. In the West, astrology most consists of a system of horoscopes purporting to explain aspects of a person's personality and predict future events in their life based on the positions of the sun and other celestial objects at the time of their birth; the majority of professional astrologers rely on such systems. Astrology has been dated to at least the 2nd millennium BCE, with roots in calendrical systems used to predict seasonal shifts and to interpret celestial cycles as signs of divine communications. A form of astrology was practised in the first dynasty of Mesopotamia. Vedāṅga Jyotiṣa, is one of earliest known Hindu texts on astrology; the text is dated between 1400 BCE to final centuries BCE by various scholars according to astronomical and linguistic evidences.
Chinese astrology was elaborated in the Zhou dynasty. Hellenistic astrology after 332 BCE mixed Babylonian astrology with Egyptian Decanic astrology in Alexandria, creating horoscopic astrology. Alexander the Great's conquest of Asia allowed astrology to spread to Ancient Rome. In Rome, astrology was associated with'Chaldean wisdom'. After the conquest of Alexandria in the 7th century, astrology was taken up by Islamic scholars, Hellenistic texts were translated into Arabic and Persian. In the 12th century, Arabic texts were translated into Latin. Major astronomers including Tycho Brahe, Johannes Kepler and Galileo practised as court astrologers. Astrological references appear in literature in the works of poets such as Dante Alighieri and Geoffrey Chaucer, of playwrights such as Christopher Marlowe and William Shakespeare. Throughout most of its history, astrology was considered a scholarly tradition, it was accepted in political and academic contexts, was connected with other studies, such as astronomy, alchemy and medicine.
At the end of the 17th century, new scientific concepts in astronomy and physics called astrology into question. Astrology thus lost its academic and theoretical standing, common belief in astrology has declined. Astrology, in its broadest sense, is the search for meaning in the sky. Early evidence for humans making conscious attempts to measure and predict seasonal changes by reference to astronomical cycles, appears as markings on bones and cave walls, which show that lunar cycles were being noted as early as 25,000 years ago; this was a first step towards recording the Moon's influence upon tides and rivers, towards organising a communal calendar. Farmers addressed agricultural needs with increasing knowledge of the constellations that appear in the different seasons—and used the rising of particular star-groups to herald annual floods or seasonal activities. By the 3rd millennium BCE, civilisations had sophisticated awareness of celestial cycles, may have oriented temples in alignment with heliacal risings of the stars.
Scattered evidence suggests that the oldest known astrological references are copies of texts made in the ancient world. The Venus tablet of Ammisaduqa is thought to be compiled in Babylon around 1700 BCE. A scroll documenting an early use of electional astrology is doubtfully ascribed to the reign of the Sumerian ruler Gud
Neptune is the eighth and farthest known planet from the Sun in the Solar System. In the Solar System, it is the fourth-largest planet by diameter, the third-most-massive planet, the densest giant planet. Neptune is 17 times the mass of Earth more massive than its near-twin Uranus. Neptune is denser and physically smaller than Uranus because its greater mass causes more gravitational compression of its atmosphere. Neptune orbits the Sun once every 164.8 years at an average distance of 30.1 AU. It is named after the Roman god of the sea and has the astronomical symbol ♆, a stylised version of the god Neptune's trident. Neptune is not visible to the unaided eye and is the only planet in the Solar System found by mathematical prediction rather than by empirical observation. Unexpected changes in the orbit of Uranus led Alexis Bouvard to deduce that its orbit was subject to gravitational perturbation by an unknown planet. Neptune was subsequently observed with a telescope on 23 September 1846 by Johann Galle within a degree of the position predicted by Urbain Le Verrier.
Its largest moon, was discovered shortly thereafter, though none of the planet's remaining known 13 moons were located telescopically until the 20th century. The planet's distance from Earth gives it a small apparent size, making it challenging to study with Earth-based telescopes. Neptune was visited by Voyager 2, when it flew by the planet on 25 August 1989; the advent of the Hubble Space Telescope and large ground-based telescopes with adaptive optics has allowed for additional detailed observations from afar. Like Jupiter and Saturn, Neptune's atmosphere is composed of hydrogen and helium, along with traces of hydrocarbons and nitrogen, though it contains a higher proportion of "ices" such as water and methane. However, similar to Uranus, its interior is composed of ices and rock. Traces of methane in the outermost regions in part account for the planet's blue appearance. In contrast to the hazy featureless atmosphere of Uranus, Neptune's atmosphere has active and visible weather patterns.
For example, at the time of the Voyager 2 flyby in 1989, the planet's southern hemisphere had a Great Dark Spot comparable to the Great Red Spot on Jupiter. These weather patterns are driven by the strongest sustained winds of any planet in the Solar System, with recorded wind speeds as high as 2,100 km/h; because of its great distance from the Sun, Neptune's outer atmosphere is one of the coldest places in the Solar System, with temperatures at its cloud tops approaching 55 K. Temperatures at the planet's centre are 5,400 K. Neptune has a faint and fragmented ring system, discovered in 1984 later confirmed by Voyager 2; some of the earliest recorded observations made through a telescope, Galileo's drawings on 28 December 1612 and 27 January 1613 contain plotted points that match up with what is now known to be the position of Neptune. On both occasions, Galileo seems to have mistaken Neptune for a fixed star when it appeared close—in conjunction—to Jupiter in the night sky. At his first observation in December 1612, Neptune was stationary in the sky because it had just turned retrograde that day.
This apparent backward motion is created. Because Neptune was only beginning its yearly retrograde cycle, the motion of the planet was far too slight to be detected with Galileo's small telescope. In July 2009, University of Melbourne physicist David Jamieson announced new evidence suggesting that Galileo was at least aware that the "star" he had observed had moved relative to the fixed stars. In 1821, Alexis Bouvard published astronomical tables of the orbit of Neptune's neighbour Uranus. Subsequent observations revealed substantial deviations from the tables, leading Bouvard to hypothesise that an unknown body was perturbing the orbit through gravitational interaction. In 1843, John Couch Adams began work on the orbit of Uranus using the data. Via Cambridge Observatory director James Challis, he requested extra data from Sir George Airy, the Astronomer Royal, who supplied it in February 1844. Adams produced several different estimates of a new planet. In 1845–46, Urbain Le Verrier, independently of Adams, developed his own calculations but aroused no enthusiasm in his compatriots.
In June 1846, upon seeing Le Verrier's first published estimate of the planet's longitude and its similarity to Adams's estimate, Airy persuaded Challis to search for the planet. Challis vainly scoured the sky throughout September. Meanwhile, Le Verrier by letter urged Berlin Observatory astronomer Johann Gottfried Galle to search with the observatory's refractor. Heinrich d'Arrest, a student at the observatory, suggested to Galle that they could compare a drawn chart of the sky in the region of Le Verrier's predicted location with the current sky to seek the displacement characteristic of a planet, as opposed to a fixed star. On the evening of 23 September 1846, the day Galle received the letter, he discovered Neptune within 1° of where Le Verrier had predicted it to be, about 12° from Adams' prediction. Challis realised that he had observed the planet twice, on 4 and 12 August, but did not recognise it as a planet because he lacked an up-to-date star map and was distracted by his concurrent work on comet observations.
In the wake of the discovery, there was much nationalistic rivalry between the French and the British over who deserved credit for the discovery. An international consen
Sound recording and reproduction
Sound recording and reproduction is an electrical, electronic, or digital inscription and re-creation of sound waves, such as spoken voice, instrumental music, or sound effects. The two main classes of sound recording technology are analog digital recording. Acoustic analog recording is achieved by a microphone diaphragm that senses changes in atmospheric pressure caused by acoustic sound waves and records them as a mechanical representation of the sound waves on a medium such as a phonograph record. In magnetic tape recording, the sound waves vibrate the microphone diaphragm and are converted into a varying electric current, converted to a varying magnetic field by an electromagnet, which makes a representation of the sound as magnetized areas on a plastic tape with a magnetic coating on it. Analog sound reproduction is the reverse process, with a bigger loudspeaker diaphragm causing changes to atmospheric pressure to form acoustic sound waves. Digital recording and reproduction converts the analog sound signal picked up by the microphone to a digital form by the process of sampling.
This lets the audio data be transmitted by a wider variety of media. Digital recording stores audio as a series of binary numbers representing samples of the amplitude of the audio signal at equal time intervals, at a sample rate high enough to convey all sounds capable of being heard. A digital audio signal must be reconverted to analog form during playback before it is amplified and connected to a loudspeaker to produce sound. Prior to the development of sound recording, there were mechanical systems, such as wind-up music boxes and player pianos, for encoding and reproducing instrumental music. Long before sound was first recorded, music was recorded—first by written music notation also by mechanical devices. Automatic music reproduction traces back as far as the 9th century, when the Banū Mūsā brothers invented the earliest known mechanical musical instrument, in this case, a hydropowered organ that played interchangeable cylinders. According to Charles B. Fowler, this "...cylinder with raised pins on the surface remained the basic device to produce and reproduce music mechanically until the second half of the nineteenth century."
The Banū Mūsā brothers invented an automatic flute player, which appears to have been the first programmable machine. Carvings in the Rosslyn Chapel from the 1560s may represent an early attempt to record the Chladni patterns produced by sound in stone representations, although this theory has not been conclusively proved. In the 14th century, a mechanical bell-ringer controlled by a rotating cylinder was introduced in Flanders. Similar designs appeared in barrel organs, musical clocks, barrel pianos, music boxes. A music box is an automatic musical instrument that produces sounds by the use of a set of pins placed on a revolving cylinder or disc so as to pluck the tuned teeth of a steel comb; the fairground organ, developed in 1892, used a system of accordion-folded punched cardboard books. The player piano, first demonstrated in 1876, used a punched paper scroll that could store a long piece of music; the most sophisticated of the piano rolls were hand-played, meaning that the roll represented the actual performance of an individual, not just a transcription of the sheet music.
This technology to record a live performance onto a piano roll was not developed until 1904. Piano rolls were in continuous mass production from 1896 to 2008. A 1908 U. S. Supreme Court copyright case noted that, in 1902 alone, there were between 70,000 and 75,000 player pianos manufactured, between 1,000,000 and 1,500,000 piano rolls produced; the first device that could record actual sounds as they passed through the air was the phonautograph, patented in 1857 by Parisian inventor Édouard-Léon Scott de Martinville. The earliest known recordings of the human voice are phonautograph recordings, called phonautograms, made in 1857, they consist of sheets of paper with sound-wave-modulated white lines created by a vibrating stylus that cut through a coating of soot as the paper was passed under it. An 1860 phonautogram of Au Clair de la Lune, a French folk song, was played back as sound for the first time in 2008 by scanning it and using software to convert the undulating line, which graphically encoded the sound, into a corresponding digital audio file.
On April 30, 1877, French poet, humorous writer and inventor Charles Cros submitted a sealed envelope containing a letter to the Academy of Sciences in Paris explaining his proposed method, called the paleophone. Though no trace of a working paleophone was found, Cros is remembered as the earliest inventor of a sound recording and reproduction machine; the first practical sound recording and reproduction device was the mechanical phonograph cylinder, invented by Thomas Edison in 1877 and patented in 1878. The invention soon spread across the globe and over the next two decades the commercial recording and sale of sound recordings became a growing new international industry, with the most popular titles selling millions of units by the early 1900s; the development of mass-production techniques enabled cylinder recordings to become a major new consumer item in industrial countries and the cylinder was the main consumer format from the late 1880s until around 1910. The next major technical development was the invention of the gramophone record credited to Emile Berliner and patented in 1887, though others had demonstrated simi
Earth is the third planet from the Sun and the only astronomical object known to harbor life. According to radiometric dating and other sources of evidence, Earth formed over 4.5 billion years ago. Earth's gravity interacts with other objects in space the Sun and the Moon, Earth's only natural satellite. Earth revolves around the Sun in a period known as an Earth year. During this time, Earth rotates about its axis about 366.26 times. Earth's axis of rotation is tilted with respect to its orbital plane; the gravitational interaction between Earth and the Moon causes ocean tides, stabilizes Earth's orientation on its axis, slows its rotation. Earth is the largest of the four terrestrial planets. Earth's lithosphere is divided into several rigid tectonic plates that migrate across the surface over periods of many millions of years. About 71% of Earth's surface is covered with water by oceans; the remaining 29% is land consisting of continents and islands that together have many lakes and other sources of water that contribute to the hydrosphere.
The majority of Earth's polar regions are covered in ice, including the Antarctic ice sheet and the sea ice of the Arctic ice pack. Earth's interior remains active with a solid iron inner core, a liquid outer core that generates the Earth's magnetic field, a convecting mantle that drives plate tectonics. Within the first billion years of Earth's history, life appeared in the oceans and began to affect the Earth's atmosphere and surface, leading to the proliferation of aerobic and anaerobic organisms; some geological evidence indicates. Since the combination of Earth's distance from the Sun, physical properties, geological history have allowed life to evolve and thrive. In the history of the Earth, biodiversity has gone through long periods of expansion punctuated by mass extinction events. Over 99% of all species that lived on Earth are extinct. Estimates of the number of species on Earth today vary widely. Over 7.6 billion humans live on Earth and depend on its biosphere and natural resources for their survival.
Humans have developed diverse cultures. The modern English word Earth developed from a wide variety of Middle English forms, which derived from an Old English noun most spelled eorðe, it has cognates in every Germanic language, their proto-Germanic root has been reconstructed as *erþō. In its earliest appearances, eorðe was being used to translate the many senses of Latin terra and Greek γῆ: the ground, its soil, dry land, the human world, the surface of the world, the globe itself; as with Terra and Gaia, Earth was a personified goddess in Germanic paganism: the Angles were listed by Tacitus as among the devotees of Nerthus, Norse mythology included Jörð, a giantess given as the mother of Thor. Earth was written in lowercase, from early Middle English, its definite sense as "the globe" was expressed as the earth. By Early Modern English, many nouns were capitalized, the earth became the Earth when referenced along with other heavenly bodies. More the name is sometimes given as Earth, by analogy with the names of the other planets.
House styles now vary: Oxford spelling recognizes the lowercase form as the most common, with the capitalized form an acceptable variant. Another convention capitalizes "Earth" when appearing as a name but writes it in lowercase when preceded by the, it always appears in lowercase in colloquial expressions such as "what on earth are you doing?" The oldest material found in the Solar System is dated to 4.5672±0.0006 billion years ago. By 4.54±0.04 Bya the primordial Earth had formed. The bodies in the Solar System evolved with the Sun. In theory, a solar nebula partitions a volume out of a molecular cloud by gravitational collapse, which begins to spin and flatten into a circumstellar disk, the planets grow out of that disk with the Sun. A nebula contains gas, ice grains, dust. According to nebular theory, planetesimals formed by accretion, with the primordial Earth taking 10–20 million years to form. A subject of research is the formation of some 4.53 Bya. A leading hypothesis is that it was formed by accretion from material loosed from Earth after a Mars-sized object, named Theia, hit Earth.
In this view, the mass of Theia was 10 percent of Earth, it hit Earth with a glancing blow and some of its mass merged with Earth. Between 4.1 and 3.8 Bya, numerous asteroid impacts during the Late Heavy Bombardment caused significant changes to the greater surface environment of the Moon and, by inference, to that of Earth. Earth's atmosphere and oceans were formed by volcanic outgassing. Water vapor from these sources condensed into the oceans, augmented by water and ice from asteroids and comets. In this model, atmospheric "greenhouse gases" kept the oceans from freezing when the newly forming Sun had only 70% of its current luminosity. By 3.5 Bya, Earth's magnetic field was established, which helped prevent the atmosphere from being stripped away by the solar wind. A crust formed; the two models that explain land mass propose either a steady growth to the present-day forms or, more a rapid growth early in Earth history followed by a long-term steady continental area. Continents formed by plate tectonics