In physics, string theory is a theoretical framework in which the point-like particles of particle physics are replaced by one-dimensional objects called strings. It describes how these strings propagate through interact with each other. On distance scales larger than the string scale, a string looks just like an ordinary particle, with its mass and other properties determined by the vibrational state of the string. In string theory, one of the many vibrational states of the string corresponds to the graviton, a quantum mechanical particle that carries gravitational force, thus string theory is a theory of quantum gravity. String theory is a broad and varied subject that attempts to address a number of deep questions of fundamental physics. String theory has been applied to a variety of problems in black hole physics, early universe cosmology, nuclear physics, condensed matter physics, it has stimulated a number of major developments in pure mathematics; because string theory provides a unified description of gravity and particle physics, it is a candidate for a theory of everything, a self-contained mathematical model that describes all fundamental forces and forms of matter.
Despite much work on these problems, it is not known to what extent string theory describes the real world or how much freedom the theory allows in the choice of its details. String theory was first studied in the late 1960s as a theory of the strong nuclear force, before being abandoned in favor of quantum chromodynamics. Subsequently, it was realized that the properties that made string theory unsuitable as a theory of nuclear physics made it a promising candidate for a quantum theory of gravity; the earliest version of string theory, bosonic string theory, incorporated only the class of particles known as bosons. It developed into superstring theory, which posits a connection called supersymmetry between bosons and the class of particles called fermions. Five consistent versions of superstring theory were developed before it was conjectured in the mid-1990s that they were all different limiting cases of a single theory in eleven dimensions known as M-theory. In late 1997, theorists discovered an important relationship called the AdS/CFT correspondence, which relates string theory to another type of physical theory called a quantum field theory.
One of the challenges of string theory is that the full theory does not have a satisfactory definition in all circumstances. Another issue is that the theory is thought to describe an enormous landscape of possible universes, this has complicated efforts to develop theories of particle physics based on string theory; these issues have led some in the community to criticize these approaches to physics and question the value of continued research on string theory unification. In the twentieth century, two theoretical frameworks emerged for formulating the laws of physics; the first is Albert Einstein's general theory of relativity, a theory that explains the force of gravity and the structure of space and time. The other is quantum mechanics, a different formulation to describe physical phenomena using the known probability principles. By the late 1970s, these two frameworks had proven to be sufficient to explain most of the observed features of the universe, from elementary particles to atoms to the evolution of stars and the universe as a whole.
In spite of these successes, there are still many problems. One of the deepest problems in modern physics is the problem of quantum gravity; the general theory of relativity is formulated within the framework of classical physics, whereas the other fundamental forces are described within the framework of quantum mechanics. A quantum theory of gravity is needed in order to reconcile general relativity with the principles of quantum mechanics, but difficulties arise when one attempts to apply the usual prescriptions of quantum theory to the force of gravity. In addition to the problem of developing a consistent theory of quantum gravity, there are many other fundamental problems in the physics of atomic nuclei, black holes, the early universe. String theory is a theoretical framework that attempts to address many others; the starting point for string theory is the idea that the point-like particles of particle physics can be modeled as one-dimensional objects called strings. String theory describes how strings propagate through interact with each other.
In a given version of string theory, there is only one kind of string, which may look like a small loop or segment of ordinary string, it can vibrate in different ways. On distance scales larger than the string scale, a string will look just like an ordinary particle, with its mass and other properties determined by the vibrational state of the string. In this way, all of the different elementary particles may be viewed as vibrating strings. In string theory, one of the vibrational states of the string gives rise to the graviton, a quantum mechanical particle that carries gravitational force, thus string theory is a theory of quantum gravity. One of the main developments of the past several decades in string theory was the discovery of certain "dualities", mathematical transformations that identify one physical theory with another. Physicists studying string theory have discovered a number of these dualities between different versions of string theory, this has led to the conjecture that all consistent versions of string theory are subsumed in a single framework known as M-theory.
Studies of string theory have yielded a number of results on the nature of black holes and the gravitational interaction. There are certain paradoxes that arise when one attempts to understand the quantum aspects of black holes, work on string theory
Nixon Public School was an elementary school in Norfolk County, Canada that started out as a one room schoolhouse in the mid to late 19th century. During the 1950s, the school was moved to a centralized building; the one-room schoolhouse was sold to become a private residence and Nixon Public School became a centralized school until was closed on September 2001 due to cutbacks in education spending. After the property was put up for sale by the Grand Erie District School Board and turned down by the Brant Haldimand Norfolk Catholic District School Board, a private agriculture-related business purchased the building from the school board; the former public school was converted into a craft brewery and pub. "New Limburg" Brewery is owned and operated by a family from the Netherlands, who brew several different Belgian-style beers. They are open daily until 11 pm for sales. Http://newlimburg.com/ Norfolk County council had to approve the land's zoning change from educational to light industrial in order for Norfolk County's third microbrewery to be possible according to their set of by-laws.
Some of the chalkboards from the old Nixon Public School have been preserved and service is available in the coldest winter months. The beers served at this establishment range from being of average quality to excellent quality. Most customers spend less than 60 minutes in this establishment. Most of its students lived an area that surrounded the communities of Lynnville, Atherton and Blayney. Children from the communities of Gilbertville and Pine Grove only attended Nixon Public School because Delhi Public School didn't have special education in the 1980s and the 1990s. Standard detentions were used in the intermediate grades and were never given to special education students. Compared to most elementary schools of its time, Nixon Public School was one of the safest schools when it came to bullying. Mrs. Virginia Chambers was the school's librarian before she was promoted to become the last principal of Nixon Public School. Like most elementary school libraries, the Nixon Public School library had children's books and a limited amount of dictionaries and encyclopedias for the older students.
Kindergarten was introduced to Nixon Public School in the 1960s to help better prepare students for the first grade. Special education was introduced in the 1970s when schools began integrating the handicapped students with other children; the last program to be introduced was junior kindergarten in the late 1990s. One of the goals of the junior kindergarten program was to better prepare students for the challenges of kindergarten according to the curriculum of the 21st century; the other goal of the junior kindergarten program was to prepare the children for a more competitive workplace environment by offering them more academia at a younger age. The name of Nixon Public School's athletic teams was collectively the Knights, they participated in sports like Tee Ball and track and field. There was a baseball field on the schoolyard, converted into a grass field after it became a part of a commercial business. Students were once fond of making snow forts in addition to singing Christmas carols and tobogganing on the hills of snow during the typical −6.2 °C weather of the winter months at Nixon Public School.
Like most schoolyards, the land used for recess was behind the school where students could be supervised easier. Land in front of the school was for vehicles and for people other than students that were permitted to be on the premises. During the late 1980s and early 1990s, the school held night dances for the older students complete with a disc jockey. Younger students could not attend the festivities; the 1988 Junior Olympics was one of the highlights of the typical Nixon Public School student. Students from all grades were rewarded by being Nixon Public School's Student of the Week; this prestigious intramural award was given to the student with the best maturity and efforts towards his or her academic work for an entire school week. Material rewards came in the form of a pencil that said "Nixon Public School Student of the Week" in addition to having his or her name on the "Student of the Week" wall for all staff and students to see. Special education was taught freestyle at this school. Instead of having the disabled students sit in rows, they sat in special areas with special activities being the reward for doing successful work.
For example, the tape recorder had a built-in microphone for children to record their own voice on a Compact Cassette. Any surviving cassette tapes and daily journal entries would serve today as mementos of a child's Nixon Public School years. Many parents have kept pictures. However, cassettes have been either taped over or placed in the garbage after a certain number of years. Students who misbehaved in special education got sent to the time out corner, a yellowish chair facing the southwest corner of the room. Mrs. McCall once taught religious studies to the disabled children in special education class prior to the Ontario government banning prayer in public schools in the early 1990s, her presence in the late 1980s helped to complement a more Christian thinking in the Ontario public school administration of that time. Through religious songs and stories from the Bible, the focus was on getting the children to pay attention to stories while expanding their attention span and improving eye contact with the person, telling the story
Nyamagasani I Hydroelectric Power Station Nyamagasani 1 Hydroelectric Power Station is a 15 megawatts hydroelectric power project, under construction in Uganda. The power station is located near the village of Kyarumba, in Kasese District 45.3 kilometres, by road, south-west of Kasese, the nearest large town. Nyamagasani I Hydroelectric Power Station is a run-of-river hydro-power plant, with initial planned capacity installation of 15 megawatts, when completed; the project lies across the Nyamagasani River, adjacent to its sister project, Nyamagasani II Hydroelectric Power Station, high in the foothills of the Rwenzori Mountains, at an average elevation of about 1,392 metres. The project company, Rwenzori Hydro Private Limited, is majority-owned by DI Frontier Market Energy & Carbon Fund, a Denmark-based renewable energy investment company; the construction of this power station is budgeted at US$36.7 million, with US$9.4 million, in GetFit concessions. List of power stations in Uganda List of hydropower stations in Africa Micro Dams To The Rescue