Weak interaction

In nuclear physics and particle physics, the weak interaction, often called the weak force or weak nuclear force, is the mechanism of interaction between subatomic particles, responsible for the radioactive decay of atoms. The weak interaction serves an essential role in nuclear fission, the theory regarding it in terms of both its behavior and effects is sometimes called quantum flavordynamics. However, the term QFD is used, because the weak force is better understood in terms of electroweak theory. In addition to this, QFD is related to quantum chromodynamics, which deals with the strong interaction, quantum electrodynamics, which deals with the electromagnetic force; the effective range of the weak force is limited to subatomic distances, is less than the diameter of a proton. It is one of the four known force-related fundamental interactions of nature, alongside the strong interaction and gravitation; the Standard Model of particle physics provides a uniform framework for understanding the electromagnetic and strong interactions.

An interaction occurs when two particles exchange force-carrying bosons. The fermions involved in such exchanges can be either elementary or composite, although at the deepest levels, all weak interactions are between elementary particles. In the weak interaction, fermions can exchange three types of force carriers, namely W+, W−, Z bosons; the masses of these bosons are far greater than the mass of a proton or neutron, consistent with the short range of the weak force. In fact, the force is termed weak because its field strength over a given distance is several orders of magnitude less than that of the strong nuclear force or electromagnetic force. Quarks, which make up composite particles like neutrons and protons, come in six "flavors" – up, strange, charm and bottom – which give those composite particles their properties; the weak interaction is unique in. The swapping of those properties is mediated by the force carrier bosons. For example, during beta minus decay, a down quark within a neutron is changed into an up quark, thus converting the neutron to a proton and resulting in the emission of an electron and an electron antineutrino.

The weak interaction is the only fundamental interaction that breaks parity-symmetry, the only one to break charge parity symmetry. Other important examples of phenomena involving the weak interaction include beta decay, the fusion of hydrogen into helium that powers the Sun's thermonuclear process. Most fermions decay by a weak interaction over time; such decay makes radiocarbon dating possible, as carbon-14 decays through the weak interaction to nitrogen-14. It can create radioluminescence used in tritium illumination, in the related field of betavoltaics. During the quark epoch of the early universe, the electroweak force separated into the electromagnetic and weak forces. In 1933, Enrico Fermi proposed the first theory of the weak interaction, known as Fermi's interaction, he suggested that beta decay could be explained by a four-fermion interaction, involving a contact force with no range. However, it is better described as a non-contact force field having a finite range, albeit short. In 1968, Sheldon Glashow, Abdus Salam and Steven Weinberg unified the electromagnetic force and the weak interaction by showing them to be two aspects of a single force, now termed the electroweak force.

The existence of the W and Z bosons was not directly confirmed until 1983. The electrically charged weak interaction is unique in a number of respects: It is the only interaction that can change the flavor of quarks, it is the only interaction that violates parity-symmetry. It is the only one that violates charge-parity CP symmetry. Both the electrically charged and the electrically neutral interactions are mediated by force carrier particles that have significant masses, an unusual feature, explained in the Standard Model by the Higgs mechanism. Due to their large mass these carrier particles, called the W and Z bosons, are short-lived with a lifetime of under 10−24 seconds; the weak interaction has a coupling constant of between 10−7 and 10−6, compared to the strong interaction's coupling constant of 1 and the electromagnetic coupling constant of about 10−2. The weak interaction has a short effective range. At distances around 10−18 meters, the weak interaction has a strength of a similar magnitude to the electromagnetic force, but this starts to decrease exponentially with increasing distance.

Scaled up by just one and a half orders of magnitude, at distances of around 3×10−17 m, the weak interaction becomes 10,000 times weaker. The weak interaction affects all the fermions of the Standard Model, as well as the Higgs boson; the weak interaction does not produce bound states nor does it involve binding energy – something that gravity does on an astronomical scale, that the electromagnetic force does at the atomic level, that the strong nuclear force does inside nuclei. Its most noticeable effect is due to its first unique feature: The charged weak interaction causes flavor change. For example, a neutron is heavier than a proton, can decay into a proton by changing the flavor of one o

2002 NBA playoffs

The 2002 NBA playoffs were the postseason tournament of the National Basketball Association's 2001–02 season. This was the final postseason; the tournament concluded with the Western Conference champion Los Angeles Lakers defeating the Eastern Conference champion New Jersey Nets 4 games to 0. Shaquille O'Neal was named NBA Finals MVP for the third straight year; this year marked the return of playoff success for the Boston Celtics, who had last made the playoffs in 1995, won their last playoff series in 1992 and made their last Eastern Conference Finals appearance in 1988. Though they lost to the Nets 4–2, they did create the biggest 4th quarter playoff comeback in Game 3, winning 94–90 after trailing by as much as 21 prior to the fourth quarter.. The Detroit Pistons won their first playoff series since 1991, they would lose in the Eastern Conference Semifinals to the Celtics in five games. The playoffs marked the last appearance of the Charlotte Hornets in the playoffs until 2010; the Hornets moved the next year to New Orleans, while an expansion team the Bobcats, was formed in 2004.

The Hornets were renamed the Pelicans in 2013, after which the Bobcats reclaimed the Hornets name in 2014. The Hornets reclaimed the history and records of the 1988–2002 Charlotte teams; the Charlotte Coliseum played host to its final playoff game on May 12. The playoffs marked the last time TBS aired NBA games as regular TV partners of the league; the last TBS-aired game under its various contracts was Game 5 of the Lakers-Spurs series, while Game 4 of the NBA Finals marked the last telecast on NBC. TBS and NBC were replaced with ESPN and ABC the following season, since both channels are owned by the Walt Disney Company. TBS has aired some NBA basketball in the ensuing years due to conflicts on sister network TNT. Pat Riley missed the playoffs for the first time in his coaching career; the total number of playoff games was 70, including the NBA Finals. * Division winnerBold Series winnerItalic Team with home-court advantage The Sacramento Kings clinched the best record in the NBA, earned home court advantage throughout the entire playoffs.

The following teams clinched a playoff berth in the West: Sacramento Kings San Antonio Spurs Los Angeles Lakers Dallas Mavericks Minnesota Timberwolves Portland Trail Blazers Seattle SuperSonics Utah Jazz New Jersey Nets The following teams clinched a playoff berth in the East: New Jersey Nets Detroit Pistons Boston Celtics Charlotte Hornets Orlando Magic Philadelphia 76ers Toronto Raptors Indiana Pacers Champion: Los Angeles Lakers This was the second playoff meeting between these two teams, with the Jazz winning the first meeting. This was the second playoff meeting between these two teams, with the Spurs winning the first meeting; the Lakers sweep the Blazers thanks to a series-winning 3 by Robert Horry with 2.1 seconds left in Game 3. This was the 11th playoff meeting between these two teams, with the Lakers winning eight of the first ten meetings. Dirk Nowitzki was unstoppable in this series, averaging 33 points and 16 rebounds per game; this was the first playoff meeting between the Mavericks and the Timberwolves.

This was the first playoff meeting between the Mavericks and the Kings. The Spurs were able to win only one. Bryant would pace Los Angeles to 2 crucial victories in the Alamodome with 31 points in Game 3 and a game-winning bucket in Game 4, would offset the steady production of Tim Duncan with his fourth quarter heroics, it would be San Antonio's final 2 home games in the Alamodome, as they would move into the SBC Center the following year. This was the eighth playoff meeting between these two teams, with the Lakers winning five of the first seven meetings; the 2002 Western Conference Finals is regarded as one of the best series in NBA playoff history, with the last four games coming down to the final seconds. Two games were decided on game winning shots and Game 7 was decided in overtime. However, the series was marred by controversy and allegations of corruption. On June 10, 2008, convicted NBA referee Tim Donaghy's attorney filed a court document alleging that Game 6 was fixed by two referees.

The letter states that Donaghy "learned from Referee A that Referees A and F wanted to extend the series to seven games. Tim knew Referees A and F to be'company men', always acting in the interest of the NBA, that night, it was in the NBA's interest to add another game to the series." The Lakers won Game 6 106-102, attempting 18 more free throws than the Kings in the fourth quarter, went on to win the series, the NBA championship. The document claimed that Donaghy told federal agents that in order to increase television ratings and ticket sales, "top executives of the NBA sought to manipulate games using referees", it said that NBA officials would tell referees to not call technical fouls on certain players, states that a referee was reprimanded by the league for ejecting a star player in the first quarter of a January 2000 game. Stern denied the accusations, calling Donaghy a "singing, cooperating witness"; the Lakers and Kings split the first two games in Sacramento. Lo

Frederick J. Conboy

Frederick Joseph Conboy was a Canadian politician, who served as mayor of Toronto, Ontario from 1941 to 1944. He was a member of the Orange Order in Canada. Before entering politics, Conboy was a dental surgeon, served as a professor at the Royal College of Dental Surgeons, secretary of the Ontario Dental Association and editor of the association's journal, he was educated in Toronto public and high schools and graduated from the Royal College of Dental Surgeons of Ontario. It was in 1904 that Conboy opened his office at Bloor and Westmoreland Street, a short distance from the family farm where he grew up. Since 1917 he had been professor of dental praxis at the School of Dentistry. With the Masonic Order, Orange Order and the Odd Fellows, he again was a leader, but throughout Conboy's life his first interest lay in Westmoreland United Church. A charter member and elder of Westmoreland United Church, he was for over 20 years superintendent of the Sunday school, it was believed. "The church," he said, "never fails in the matter of relief for needy citizens and there is no better place where young people can fit themselves for future citizenship than in promoting its welfare work."

One thing his closest friends never quite understood was how Conboy could find time for such a variety of activities. He belonged to two golf clubs and, in the war years, he started a victory garden, the envy of neighbours for blocks around him. While taking a holiday, he would find an occupation that would call for a fresh release of enthusiasm and energy. In 1924, while summering at Wasaga Beach, he discovered a cannonball at the edge of the Nottawasaga River. Not content with this trophy he spent the next two seasons prowling around and discovered the hull of a sunken ship buried in a large island that had formed around the wreck, he had found the remains of HMS Nancy, a British armed schooner sunk by the Americans on August 11, 1814, during the War of 1812. Conboy interested the Ontario government in the preservation of the historic relic and, thanks to his persistence, the hull was excavated, placed on the island and made available for public inspection. In recognition of his enterprise, his friends presented him with a model of the ship carved from her original timber.

In recognition of his work in public dental health, he was made a fellow of the International College of Dentists in 1919, a body composed of leading members of the profession in all parts of the world. He was a doctor of dental science at the University of Toronto, he served on the faculty of the dental college and was a member of the executive of the health section of the Ontario Educational Association. In 1925, Conboy was appointed director of dental services for the province of Ontario, he contributed much to the advancement of the profession and devoted one day a week to organizing dental services in Toronto schools. In 1926 he became director of dental service for a position he held for ten years, he served for twenty years as secretary and treasurer of the Ontario Dental Association. In 1935 he was appointed a professor at the School of Optometry, he entered civic government in 1935 when elected as alderman for Ward six, polling the largest vote of any alderman-elect. Elected as aldermen at same time were future mayors Allan Lamport, Nathan Phillips and Robert Saunders.

Conboy introduced resolutions which keynoted his public career: resolutions on unemployment, slum clearance, youth placement, city planning, relief works programs, street lighting, public health education. He was elected to the board of control one year later; as a member of city council, Conboy campaigned for the development of an island airport and harbour facilities. During his wartime years in office as Mayor, Conboy began a campaign for better housing, which has resulted in such projects as Regent Park, he was responsible for the introduction of resolutions connected with unemployment, slum clearance, relief words programs, public health education, street lighting and city planning. As an impetus to the city plan to raise $1,000,000 for war equipment in 1941, he gave one-fifth of his controller's salary, he was first elected mayor with a majority of 22,000 votes. The following day, he modestly confessed that, because of the light poll, he figured he was going down to defeat. In 1942 he received an acclamation.

Responding to an appeal to boost Canada's Reserve Army, he joined The Queen's Own Rifles of Canada as a Private and accompanied his unit to camp at Niagara as Corporal Conboy. During his fourth term, he was elected president of the Canadian Federation of Mayors, he was defeated by Robert Hood Saunders in the election of 1945. Four times Mayor of Toronto and prominent in the dental profession and welfare service, Conboy was the youngest of James and Sarah Conboy's seven children, he was mayor of Toronto during 1941-42-43-44. He had served for four years as controller and two years as alderman in Ward 7, he was a member of the Board of Education from 1909 to 1914, served a term as chairman. Conboy was a member of the board of directors of the Social Service Council of Ontario and had been prominent as organizer in social welfare in his own profession. A president of the Community Welfare Council of Ontario, Conboy many times stated he felt public officials should be part of a church community. "I know my work there has been a worthwhile task", he said, regarding his position as Sunday school superintendent at Westmoreland church.

"Never did a church school have as much responsibility as it has today in these troublous times." In May 1943, at a convention of the Ontario Dental Association, Conboy was h