|
Allegheny Observatory
The Allegheny Observatory is an American astronomical research institution, a part of the Department of Physics and Astronomy at the University of Pittsburgh. The facility is listed on the National Register of Historic Places (ref. # 79002157, added June 22, 1979) and is designated as a Pennsylvania state and Pittsburgh History and Landmarks Foundation historic landmark. History The observatory was founded on February 15, 1859, in the city of Allegheny, Pennsylvania (incorporated into the City of Pittsburgh in 1907) by a group of wealthy industrialists calling themselves the Allegheny Telescope Association. The observatory's initial purpose was for general public education as opposed to research, but by 1867 the revenues derived from this had receded. The facility was then donated to the Western University of Pennsylvania, today known as the University of Pittsburgh. The University hired Samuel Pierpont Langley to be the first director. One of the research programs init ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
University Of Pittsburgh
The University of Pittsburgh (Pitt) is a Commonwealth System of Higher Education, state-related research university in Pittsburgh, Pennsylvania, United States. The university is composed of seventeen undergraduate and graduate schools and colleges at its Urban university, urban Pittsburgh campus, home to the university's central administration and around 28,000 undergraduate and graduate students. The 132-acre Pittsburgh campus includes various historic buildings that are part of the Schenley Farms Historic District, most notably its 42-story Gothic Revival architecture, Gothic revival centerpiece, the Cathedral of Learning. Pitt is a member of the Association of American Universities and is Carnegie Classification of Institutions of Higher Education, classified among "R1: Doctoral Universities – Very high research activity". Pitt traces its roots to the Pittsburgh Academy founded by Hugh Henry Brackenridge in 1787. While the city was still on the History of Pittsburgh#Gatewa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pennsylvania Railroad
The Pennsylvania Railroad ( reporting mark PRR), legal name as the Pennsylvania Railroad Company, also known as the "Pennsy," was an American Class I railroad that was established in 1846 and headquartered in Philadelphia, Pennsylvania. At its peak in 1882, the Pennsylvania Railroad was the largest railroad (by traffic and revenue), the largest transportation enterprise, and the largest corporation in the world. Over its existence, Pennsylvania Railroad acquired, merged with, or owned part of at least 800 other rail lines and companies. At the end of 1926, it operated of rail line;This mileage includes companies independently operated. PRR miles of all tracks, which includes first (or main), second, third, fourth, and sidings, totalled 28,040.49 at the end of 1926. in the 1920s, it carried nearly three times the traffic as other railroads of comparable length, such as the Union Pacific and Atchison, Topeka & Santa Fe railroads. Its only formidable rival was the New York Centra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
John Brashear
John Alfred Brashear (November 24, 1840 – April 8, 1920) was an American astronomer and instrument builder. Life and work Brashear was born in Brownsville, Pennsylvania, a town located 35 miles (56 km) south of Pittsburgh, Pennsylvania, Pittsburgh along the Monongahela River. His father, Basil Brown Brashear, worked as a saddler, while his mother, Julia Smith Brashear, was a school teacher. He was the oldest of seven children. As a young boy, John Brashear was profoundly influenced by his maternal grandfather, Nathanial Smith, who was a clock repairer. At the age of nine, his grandfather took him to peer through the telescope of 'Squire' Joseph P. Wampler, who often set up his traveling telescope in Brownsville. This formative experience of viewing the moon and the planet Saturn stayed with Brashear throughout his life. After receiving a common school education until the age of 15, he began an apprenticeship with a machinist and had mastered his trade by the age of 20. B ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
James Clerk Maxwell
James Clerk Maxwell (13 June 1831 – 5 November 1879) was a Scottish physicist and mathematician who was responsible for the classical theory of electromagnetic radiation, which was the first theory to describe electricity, magnetism and light as different manifestations of the same phenomenon. Maxwell's equations for electromagnetism achieved the Unification (physics)#Unification of magnetism, electricity, light and related radiation, second great unification in physics, where Unification (physics)#Unification of gravity and astronomy, the first one had been realised by Isaac Newton. Maxwell was also key in the creation of statistical mechanics. With the publication of "A Dynamical Theory of the Electromagnetic Field" in 1865, Maxwell demonstrated that electric force, electric and magnetic fields travel through space as waves moving at the speed of light. He proposed that light is an undulation in the same medium that is the cause of electric and magnetic phenomena. (Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
James Edward Keeler
James Edward Keeler (September 10, 1857 – August 12, 1900) was an American astronomer. He was an early observer of galaxies using photography, as well as the first to show observationally that the rings of Saturn do not rotate as a solid body. Career and personal life Keeler was born in La Salle Illinois, but grew up and spent the majority of his early life in Mayport, Florida near Jacksonville. His mother's father was a former Governor of Connecticut, Henry Dutton. Keeler worked at Lick Observatory beginning in 1888 but left after being appointed director of the University of Pittsburgh's Allegheny Observatory in 1891. He returned to Lick Observatory as its director in 1898 but died not long after in 1900. Keeler suffered from a heart weakness that went undiagnosed until shortly before his death. On the 12th of August, he died from a sudden stroke. His ashes were interred in a crypt at the base of the 31-inch Keeler Memorial telescope at the Allegheny Observatory. Alon ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Solar Constant
The solar constant (''GSC'') measures the amount of energy received by a given area one astronomical unit away from the Sun. More specifically, it is a flux density measuring mean solar electromagnetic radiation ( total solar irradiance) per unit area. It is measured on a surface perpendicular to the rays, one astronomical unit (au) from the Sun (roughly the distance from the Sun to the Earth). The solar constant includes radiation over the entire electromagnetic spectrum. It is measured by satellite as being 1.361 kilowatts per square meter (kW/m2) at solar minimum (the time in the 11-year solar cycle when the number of sunspots is minimal) and approximately 0.1% greater (roughly 1.362 kW/m2) at solar maximum. The solar "constant" is not a physical constant in the modern CODATA scientific sense; that is, it is not like the Planck constant or the speed of light which are absolutely constant in physics. The solar constant is an average of a varying value. In the past 400 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bolometer
A bolometer is a device for measuring radiant heat by means of a material having a temperature-dependent electrical resistance. It was invented in 1878 by the American astronomer Samuel Pierpont Langley. Principle of operation A bolometer consists of an absorptive element, such as a thin layer of metal, connected to a thermal reservoir (a body of constant temperature) through a thermal link. The result is that any radiation impinging on the absorptive element raises its temperature above that of the reservoir – the greater the absorbed power, the higher the temperature. The intrinsic thermal time constant, which sets the speed of the detector, is equal to the ratio of the heat capacity of the absorptive element to the thermal conductance between the absorptive element and the reservoir. The temperature change can be measured directly with an attached resistive thermometer, or the resistance of the absorptive element itself can be used as a thermometer. Metal bolometers ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
US Naval Observatory
The United States Naval Observatory (USNO) is a scientific and military facility that produces geopositioning, navigation and timekeeping data for the United States Navy and the United States Department of Defense. Established in 1830 as the Depot of Charts and Instruments, it is one of the oldest scientific agencies in the United States, and remains the country's leading facility for astronomical and timing data. The observatory is located in Northwest Washington, D.C. at the northwestern end of Embassy Row. It is among the few pre-20th century astronomical observatories located in an urban area. In 1893, in an effort to escape light pollution, it was relocated from Foggy Bottom near the city's center, to its Northwest Washington, D.C. location. The USNO has conducted significant scientific studies throughout its history, including measuring the speed of light, observing solar eclipses, and discovering the moons of Mars. Its achievements include providing data for the first r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Public Transport Timetable
A public transport timetable (also timetable and North American English schedule) is a document setting out information on public transport service times. Both public timetables to assist passengers with planning a trip and internal timetables to inform employees exist. Typically, the timetable will list the times when a service is scheduled to arrive at and depart from specified locations. It may show all movements at a particular location or all movements on a particular route or for a particular stop. Traditionally this information was provided in printed form, for example as a leaflet or poster. It is now also often available in a variety of electronic formats. In the 2000s, public transport route planners / Intermodal journey planner, intermodal journey planners have proliferated and offer traveller the convenience that the computer program looks at all timetables so the traveller doesn't need to. A "timetable" may also refer to the same information in abstract form, not s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
United States
The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 contiguous states border Canada to the north and Mexico to the south, with the semi-exclave of Alaska in the northwest and the archipelago of Hawaii in the Pacific Ocean. The United States asserts sovereignty over five Territories of the United States, major island territories and United States Minor Outlying Islands, various uninhabited islands in Oceania and the Caribbean. It is a megadiverse country, with the world's List of countries and dependencies by area, third-largest land area and List of countries and dependencies by population, third-largest population, exceeding 340 million. Its three Metropolitan statistical areas by population, largest metropolitan areas are New York metropolitan area, New York, Greater Los Angeles, Los Angel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Canada
Canada is a country in North America. Its Provinces and territories of Canada, ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, making it the world's List of countries and dependencies by area, second-largest country by total area, with the List of countries by length of coastline, world's longest coastline. Its Canada–United States border, border with the United States is the world's longest international land border. The country is characterized by a wide range of both Temperature in Canada, meteorologic and Geography of Canada, geological regions. With Population of Canada, a population of over 41million people, it has widely varying population densities, with the majority residing in List of the largest population centres in Canada, urban areas and large areas of the country being sparsely populated. Canada's capital is Ottawa and List of census metropolitan areas and agglomerations in Canada, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Telegraph
Telegraphy is the long-distance transmission of messages where the sender uses symbolic codes, known to the recipient, rather than a physical exchange of an object bearing the message. Thus flag semaphore is a method of telegraphy, whereas pigeon post is not. Ancient signalling systems, although sometimes quite extensive and sophisticated as in China, were generally not capable of transmitting arbitrary text messages. Possible messages were fixed and predetermined, so such systems are thus not true telegraphs. The earliest true telegraph put into widespread use was the Chappe telegraph, an optical telegraph invented by Claude Chappe in the late 18th century. The system was used extensively in France, and European nations occupied by France, during the Napoleonic era. The electric telegraph started to replace the optical telegraph in the mid-19th century. It was first taken up in Britain in the form of the Cooke and Wheatstone telegraph, initially used mostly as an aid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
