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Helium

Helium is a chemical element with the symbol He and atomic number 2. It is a colorless, tasteless, non-toxic, monatomic gas, the first in the noble gas group in the periodic table, its boiling point is the lowest among all the elements. Helium is the second lightest and second most abundant element in the observable universe, it is present at about 24% of the total elemental mass, more than 12 times the mass of all the heavier elements combined. Its abundance is similar to this in Jupiter; this is due to the high nuclear binding energy of helium-4, with respect to the next three elements after helium. This helium-4 binding energy accounts for why it is a product of both nuclear fusion and radioactive decay. Most helium in the universe is helium-4, the vast majority of, formed during the Big Bang. Large amounts of new helium are being created by nuclear fusion of hydrogen in stars. Helium is named for the Greek Titan of the Sun, Helios, it was first detected as an unknown, yellow spectral line signature in sunlight, during a solar eclipse in 1868 by Georges Rayet, Captain C. T. Haig, Norman R. Pogson, Lieutenant John Herschel, was subsequently confirmed by French astronomer, Jules Janssen.

Janssen is jointly credited with detecting the element, along with Norman Lockyer. Janssen recorded the helium spectral line during the solar eclipse of 1868, while Lockyer observed it from Britain. Lockyer was the first to propose; the formal discovery of the element was made in 1895 by two Swedish chemists, Per Teodor Cleve and Nils Abraham Langlet, who found helium emanating from the uranium ore, now not regarded as a separate mineral species but as a variety of uraninite. In 1903, large reserves of helium were found in natural gas fields in parts of the United States, by far the largest supplier of the gas today. Liquid helium is used in cryogenics in the cooling of superconducting magnets, with the main commercial application being in MRI scanners. Helium's other industrial uses—as a pressurizing and purge gas, as a protective atmosphere for arc welding and in processes such as growing crystals to make silicon wafers—account for half of the gas produced. A well-known but minor use is as a lifting gas in airships.

As with any gas whose density differs from that of air, inhaling a small volume of helium temporarily changes the timbre and quality of the human voice. In scientific research, the behavior of the two fluid phases of helium-4 is important to researchers studying quantum mechanics and to those looking at the phenomena, such as superconductivity, produced in matter near absolute zero. On Earth it is rare—5.2 ppm by volume in the atmosphere. Most terrestrial helium present today is created by the natural radioactive decay of heavy radioactive elements, as the alpha particles emitted by such decays consist of helium-4 nuclei; this radiogenic helium is trapped with natural gas in concentrations as great as 7% by volume, from which it is extracted commercially by a low-temperature separation process called fractional distillation. Terrestrial helium—a non-renewable resource, once released into the atmosphere it escapes into space—was thought to be in short supply. However, recent studies suggest that helium produced deep in the earth by radioactive decay can collect in natural gas reserves in larger than expected quantities, in some cases, having been released by volcanic activity.

The first evidence of helium was observed on August 18, 1868, as a bright yellow line with a wavelength of 587.49 nanometers in the spectrum of the chromosphere of the Sun. The line was detected by French astronomer Jules Janssen during a total solar eclipse in Guntur, India; this line was assumed to be sodium. On October 20 of the same year, English astronomer, Norman Lockyer, observed a yellow line in the solar spectrum, which, he named the D3 because it was near the known D1 and D2 Fraunhofer line lines of sodium, he concluded. Lockyer and English chemist Edward Frankland named the element with the Greek word for the Sun, ἥλιος. In 1881, Italian physicist Luigi Palmieri detected helium on Earth for the first time through its D3 spectral line, when he analyzed a material, sublimated during a recent eruption of Mount Vesuvius. On March 26, 1895, Scottish chemist, Sir William Ramsay, isolated helium on Earth by treating the mineral cleveite with mineral acids. Ramsay was looking for argon but, after separating nitrogen and oxygen from the gas, liberated by sulfuric acid, he noticed a bright yellow line that matched the D3 line observed in the spectrum of the Sun.

These samples were identified as helium, by Lockyer, British physicist William Crookes. It was independently isolated from cleveite, in the same year, by chemists, Per Teodor Cleve and Abraham Langlet, in Uppsala, who collected enough of the gas to determine its atomic weight. Helium was isolated by the American geochemist, William Francis Hillebrand, prior to Ramsay's discovery, when he noticed unusual spectral lines while testing a sample of the mineral uraninite. Hillebrand, attributed the lines to nitrogen, his letter of congratulations to Ramsay offers an interesting case of discovery, near-discovery, in science. In 1907, Erne

Geoff Mardon

Geoffrey Cyril "Geoff" Mardon was a New Zealand speedway rider. He rode for the Wimbledon Dons and the Southampton Saints. Mardon began riding at the Aranui Speedway in Christchurch in 1949, the same track that would start the career of six time World Champion and fellow Christchurch native Ivan Mauger, he joined the third division team, Aldershot. He qualified as second reserve for the 1951 World Final; the following year he transferred to the Wimbledon team. He finished in 3rd place. In 1954 Mardon was one of the highest individual points scorers in the National League, he rode in the World final again and he won the Brandonapolis at Coventry. In the year he married Valerie Moore, the sister of Ronnie Moore. At the beginning of 1955 he decided to live in New Zealand. After a four-year break Southampton persuaded him to return to British speedway in 1959, he rode the Saints for a year and he qualified for the World final. Mardon won the 1964 New Zealand Championship, he died on 6 August 2015 in Christchurch.

Mardon had four appearances in world championship finals: 1951 - London, Wembley Stadium - Reserve - Did Not Ride 1953 - London, Wembley Stadium - 3rd - 12pts 1954 - London, Wembley Stadium - 11th - 5pts 1959 - London, Wembley Stadium - 10th - 6pts

Melinda Dillon

Melinda Ruth Dillon is an American actress. She received a 1963 Tony Award nomination for her Broadway debut in the original production of Who's Afraid of Virginia Woolf?, was nominated for the Academy Award for Best Supporting Actress for her roles as Jillian Guiler in Close Encounters of the Third Kind and Teresa in Absence of Malice. Her other film appearances include Bound for Glory, F. I. S. T. A Christmas Story and the Hendersons, The Prince of Tides and Magnolia. Dillon was born in Hope, the daughter of E. Norine and W. S. Dillon, an Army officer. Dillon attended Hyde Park High School in Chicago. Dillon was nominated for a Tony Award for Best Performance by a Featured Actress in a Play, her first major role. Dillon got her start as an improvisational comedian, as a stage actress as Honey in the original 1962 Broadway production of Edward Albee's Who's Afraid of Virginia Woolf, she appeared in You Know I Can't Hear You When the Water's Running and Paul Sill's Story Theatre. In 1959 she acted in The Cry of Jazz, an influential short film dealing with jazz music and Black culture.

Dillon's first feature film was The April Fools in 1969. She worked in television, notably in a guest-starring role in 1969 on an episode of the hit TV series Bonanza titled "A Lawman's Lot Is Not a Happy One", she co-starred with David Carradine in the 1976 Woody Guthrie biopic Bound for Glory and was nominated in the Best Female Acting Debut category of the Golden Globe for her role as Memphis Sue. The following year she was nominated for a Best Supporting Actress Oscar for the role of a mother whose child is abducted by aliens in Steven Spielberg's Close Encounters of the Third Kind; that same year, she made an uncredited cameo in The Muppet Movie and had a role in the comedy Slap Shot with Paul Newman. Four years Dillon was again nominated for a Best Supporting Actress Oscar for her performance as a suicidal teacher in Absence of Malice in 1981, working again with Newman; as a comedian, Dillon is best known for her role as the mother of Ralphie and Randy in Bob Clark's 1983 movie A Christmas Story.

The film was based on a series of short stories and novels written by Jean Shepherd about young Ralphie Parker and his quest for a Red Ryder BB gun from Santa Claus. Four years Dillon co-starred with John Lithgow in the Bigfoot comedy Harry and the Hendersons, she continued to be active in stage and film throughout the 1990s, taking roles in the Barbra Streisand drama The Prince of Tides, the low-budget Lou Diamond Phillips thriller Sioux City, the drama How to Make an American Quilt. In 1999 she appeared in Magnolia, directed by Paul Thomas Anderson, as Rose Gator, the estranged wife of terminally ill television game-show host Jimmy Gator. In 2005, she guest-starred in the episode of Law & Order: Special Victims Unit titled "Blood". Dillon married character actor Richard Libertini on September 30, 1963, had one child with him, Richard, they divorced in 1978. She is a Methodist. Melinda Dillon on IMDb Melinda Dillon at the TCM Movie Database