1.
Science
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Science is a systematic enterprise that builds and organizes knowledge in the form of testable explanations and predictions about the universe. The formal sciences are often excluded as they do not depend on empirical observations, disciplines which use science, like engineering and medicine, may also be considered to be applied sciences. However, during the Islamic Golden Age foundations for the method were laid by Ibn al-Haytham in his Book of Optics. In the 17th and 18th centuries, scientists increasingly sought to formulate knowledge in terms of physical laws, over the course of the 19th century, the word science became increasingly associated with the scientific method itself as a disciplined way to study the natural world. It was during this time that scientific disciplines such as biology, chemistry, Science in a broad sense existed before the modern era and in many historical civilizations. Modern science is distinct in its approach and successful in its results, Science in its original sense was a word for a type of knowledge rather than a specialized word for the pursuit of such knowledge. In particular, it was the type of knowledge which people can communicate to each other, for example, knowledge about the working of natural things was gathered long before recorded history and led to the development of complex abstract thought. This is shown by the construction of calendars, techniques for making poisonous plants edible. For this reason, it is claimed these men were the first philosophers in the strict sense and they were mainly speculators or theorists, particularly interested in astronomy. In contrast, trying to use knowledge of nature to imitate nature was seen by scientists as a more appropriate interest for lower class artisans. A clear-cut distinction between formal and empirical science was made by the pre-Socratic philosopher Parmenides, although his work Peri Physeos is a poem, it may be viewed as an epistemological essay on method in natural science. Parmenides ἐὸν may refer to a system or calculus which can describe nature more precisely than natural languages. Physis may be identical to ἐὸν and he criticized the older type of study of physics as too purely speculative and lacking in self-criticism. He was particularly concerned that some of the early physicists treated nature as if it could be assumed that it had no intelligent order, explaining things merely in terms of motion and matter. The study of things had been the realm of mythology and tradition, however. Aristotle later created a less controversial systematic programme of Socratic philosophy which was teleological and he rejected many of the conclusions of earlier scientists. For example, in his physics, the sun goes around the earth, each thing has a formal cause and final cause and a role in the rational cosmic order. Motion and change is described as the actualization of potentials already in things, while the Socratics insisted that philosophy should be used to consider the practical question of the best way to live for a human being, they did not argue for any other types of applied science
2.
United States
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Forty-eight of the fifty states and the federal district are contiguous and located in North America between Canada and Mexico. The state of Alaska is in the northwest corner of North America, bordered by Canada to the east, the state of Hawaii is an archipelago in the mid-Pacific Ocean. The U. S. territories are scattered about the Pacific Ocean, the geography, climate and wildlife of the country are extremely diverse. At 3.8 million square miles and with over 324 million people, the United States is the worlds third- or fourth-largest country by area, third-largest by land area. It is one of the worlds most ethnically diverse and multicultural nations, paleo-Indians migrated from Asia to the North American mainland at least 15,000 years ago. European colonization began in the 16th century, the United States emerged from 13 British colonies along the East Coast. Numerous disputes between Great Britain and the following the Seven Years War led to the American Revolution. On July 4,1776, during the course of the American Revolutionary War, the war ended in 1783 with recognition of the independence of the United States by Great Britain, representing the first successful war of independence against a European power. The current constitution was adopted in 1788, after the Articles of Confederation, the first ten amendments, collectively named the Bill of Rights, were ratified in 1791 and designed to guarantee many fundamental civil liberties. During the second half of the 19th century, the American Civil War led to the end of slavery in the country. By the end of century, the United States extended into the Pacific Ocean. The Spanish–American War and World War I confirmed the status as a global military power. The end of the Cold War and the dissolution of the Soviet Union in 1991 left the United States as the sole superpower. The U. S. is a member of the United Nations, World Bank, International Monetary Fund, Organization of American States. The United States is a developed country, with the worlds largest economy by nominal GDP. It ranks highly in several measures of performance, including average wage, human development, per capita GDP. While the U. S. economy is considered post-industrial, characterized by the dominance of services and knowledge economy, the United States is a prominent political and cultural force internationally, and a leader in scientific research and technological innovations. In 1507, the German cartographer Martin Waldseemüller produced a map on which he named the lands of the Western Hemisphere America after the Italian explorer and cartographer Amerigo Vespucci
3.
United States Navy
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The United States Navy is the naval warfare service branch of the United States Armed Forces and one of the seven uniformed services of the United States. The U. S. Navy is the largest, most capable navy in the world, the U. S. Navy has the worlds largest aircraft carrier fleet, with ten in service, two in the reserve fleet, and three new carriers under construction. The service has 323,792 personnel on duty and 108,515 in the Navy Reserve. It has 274 deployable combat vessels and more than 3,700 operational aircraft as of October 2016, the U. S. Navy traces its origins to the Continental Navy, which was established during the American Revolutionary War and was effectively disbanded as a separate entity shortly thereafter. It played a role in the American Civil War by blockading the Confederacy. It played the role in the World War II defeat of Imperial Japan. The 21st century U. S. Navy maintains a global presence, deploying in strength in such areas as the Western Pacific, the Mediterranean. The Navy is administratively managed by the Department of the Navy, the Department of the Navy is itself a division of the Department of Defense, which is headed by the Secretary of Defense. The Chief of Naval Operations is an admiral and the senior naval officer of the Department of the Navy. The CNO may not be the highest ranking officer in the armed forces if the Chairman or the Vice Chairman of the Joint Chiefs of Staff. The mission of the Navy is to maintain, train and equip combat-ready Naval forces capable of winning wars, deterring aggression, the United States Navy is a seaborne branch of the military of the United States. The Navys three primary areas of responsibility, The preparation of naval forces necessary for the prosecution of war. The development of aircraft, weapons, tactics, technique, organization, U. S. Navy training manuals state that the mission of the U. S. Armed Forces is to prepare and conduct prompt and sustained combat operations in support of the national interest, as part of that establishment, the U. S. Navys functions comprise sea control, power projection and nuclear deterrence, in addition to sealift duties. It follows then as certain as that night succeeds the day, that without a decisive naval force we can do nothing definitive, the Navy was rooted in the colonial seafaring tradition, which produced a large community of sailors, captains, and shipbuilders. In the early stages of the American Revolutionary War, Massachusetts had its own Massachusetts Naval Militia, the establishment of a national navy was an issue of debate among the members of the Second Continental Congress. Supporters argued that a navy would protect shipping, defend the coast, detractors countered that challenging the British Royal Navy, then the worlds preeminent naval power, was a foolish undertaking. Commander in Chief George Washington resolved the debate when he commissioned the ocean-going schooner USS Hannah to interdict British merchant ships, and reported the captures to the Congress
4.
United States Department of Defense
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The Department is the largest employer in the world, with nearly 1.3 million active duty servicemen and women as of 2016. Adding to its employees are over 801,000 National Guardsmen and Reservists from the four services and it is headquartered at the Pentagon in Arlington, Virginia, just outside of Washington, D. C. The Department of Defense is headed by the Secretary of Defense, Military operations are managed by nine regional or functional Unified Combatant Commands. The Department of Defense also operates several joint services schools, including the National Defense University, the history of the defense of the United States started with the Continental Congress in 1775. The creation of the United States Army was enacted on 14 June 1775 and this coincides with the American holiday Flag Day. The Second Continental Congress would charter the United States Navy, on 13 October 1775, today, both the Navy and the Marine Corps are separate military services subordinate to the Department of the Navy. The Preamble of the United States Constitution gave the authority to federal government, to defend its citizens and this first Congress had a huge agenda, that of creating legislation to build a government for the ages. Legislation to create a military defense force stagnated, two separate times, President George Washington went to Congress to remind them of their duty to establish a military. In a special message to Congress on 19 December 1945, the President cited both wasteful military spending and inter-departmental conflicts, deliberations in Congress went on for months focusing heavily on the role of the military in society and the threat of granting too much military power to the executive. The act placed the National Military Establishment under the control of a single Secretary of Defense, the National Military Establishment formally began operations on 18 September, the day after the Senate confirmed James V. Forrestal as the first Secretary of Defense. The National Military Establishment was renamed the Department of Defense on 10 August 1949, under the Department of Defense Reorganization Act of 1958, channels of authority within the department were streamlined, while still maintaining the authority of the Military Departments. Also provided in this legislation was a centralized authority, the Advanced Research Projects Agency. The Act moved decision-making authority from the Military Departments to the Joint Chiefs of Staff and it also strengthened the command channel of the military over U. S. forces from the President to the Secretary of Defense. Written and promoted by the Eisenhower administration, it was signed into law 6 August 1958, because the Constitution vests all military authority in Congress and the President, the statutory authority of the Secretary of Defense is derived from their constitutional authorities. Department of Defense Directive 5100.01 describes the relationships within the Department. The latest version, signed by former Secretary of Defense Robert Gates in December 2010, is the first major re-write since 1987, the Office of the Secretary of Defense is the Secretary and Deputy Secretarys civilian staff. S. Government departments and agencies, foreign governments, and international organizations, OSD also performs oversight and management of the Defense Agencies and Department of Defense Field Activities. OSD also supervises the following Defense Agencies, Several defense agencies are members of the United States Intelligence Community and these are national-level intelligence services that operate under the jurisdiction of the Department of Defense but simultaneously fall under the authorities of the Director of National Intelligence
5.
Washington, D.C.
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Washington, D. C. formally the District of Columbia and commonly referred to as Washington, the District, or simply D. C. is the capital of the United States. The signing of the Residence Act on July 16,1790, Constitution provided for a federal district under the exclusive jurisdiction of the Congress and the District is therefore not a part of any state. The states of Maryland and Virginia each donated land to form the federal district, named in honor of President George Washington, the City of Washington was founded in 1791 to serve as the new national capital. In 1846, Congress returned the land ceded by Virginia, in 1871. Washington had an population of 681,170 as of July 2016. Commuters from the surrounding Maryland and Virginia suburbs raise the population to more than one million during the workweek. The Washington metropolitan area, of which the District is a part, has a population of over 6 million, the centers of all three branches of the federal government of the United States are in the District, including the Congress, President, and Supreme Court. Washington is home to national monuments and museums, which are primarily situated on or around the National Mall. The city hosts 176 foreign embassies as well as the headquarters of international organizations, trade unions, non-profit organizations, lobbying groups. A locally elected mayor and a 13‑member council have governed the District since 1973, However, the Congress maintains supreme authority over the city and may overturn local laws. D. C. residents elect a non-voting, at-large congressional delegate to the House of Representatives, the District receives three electoral votes in presidential elections as permitted by the Twenty-third Amendment to the United States Constitution, ratified in 1961. Various tribes of the Algonquian-speaking Piscataway people inhabited the lands around the Potomac River when Europeans first visited the area in the early 17th century, One group known as the Nacotchtank maintained settlements around the Anacostia River within the present-day District of Columbia. Conflicts with European colonists and neighboring tribes forced the relocation of the Piscataway people, some of whom established a new settlement in 1699 near Point of Rocks, Maryland. 43, published January 23,1788, James Madison argued that the new government would need authority over a national capital to provide for its own maintenance. Five years earlier, a band of unpaid soldiers besieged Congress while its members were meeting in Philadelphia, known as the Pennsylvania Mutiny of 1783, the event emphasized the need for the national government not to rely on any state for its own security. However, the Constitution does not specify a location for the capital, on July 9,1790, Congress passed the Residence Act, which approved the creation of a national capital on the Potomac River. The exact location was to be selected by President George Washington, formed from land donated by the states of Maryland and Virginia, the initial shape of the federal district was a square measuring 10 miles on each side, totaling 100 square miles. Two pre-existing settlements were included in the territory, the port of Georgetown, Maryland, founded in 1751, many of the stones are still standing
6.
Embassy Row
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By extension, the name may be used to encompass nearby streets which also host diplomatic buildings. The segment between Scott Circle and Sheridan Circle gained the nickname Millionaires Row, the Great Depression caused many to sell their homes. The expansive old estates proved well-suited for use as embassies, and also as lodges of social clubs, giving Embassy Row its present name, the greatest number of embassies and chanceries moved to Embassy Row and the neighboring Kalorama neighborhood in the 1940s and early 1950s. More recently, several prominent think tanks have clustered in that area, many of Embassy Rows diplomatic buildings open to the public once a year in May, an initiative nicknamed Passport DC. This event was started in 2007 by the embassies of states of the European Union. Within this program, the EU embassies still open on a separate day, a separate program, the Embassy Series, started in 1994 and coordinates concerts organized in the embassy buildings. Embassy Row is protected as the Massachusetts Avenue Historic District, created in 1974 following controversy about the demolition of townhouses on 1722-28 Massachusetts Ave NW. Many of its buildings are listed in the DC Inventory of Historic Sites. The Western boundary used here is identical to that of the Historic District, however, some describe Embassy Row as extending as far west as Wisconsin Avenue NW. This section of Massachusetts Avenue was the one known as the Millionaires Row of Washington, D. C. in the late 19th, mcGuire House, now Embassy of Chile 1740 Massachusetts Ave NW, Paul H. S. Peyton Russell House, now Embassy of Kenya 2251 R St NW, a special case is the statue of Winston Churchill, which has one foot on the grounds of the British Embassy and the other on federal land to symbolize the UK-US alliance. In the early days of Washington, D. C. most diplomats, thorntons choice of location, at a time when Dupont Circle was still almost entirely undeveloped, may be considered the origin of Embassy Row as a diplomatic neighborhood. In the first three decades of the 20th Century, several European legations gathered farther North-East, on a section of 16th Street near Meridian Hill Park. This area was developed by local resident Mary Foote Henderson to attract embassies. However, the neighborhood was hit by the Great Depression, former embassy buildings in the Meridian Hill area include those of France, Mexico, the Netherlands, Spain, Egypt, Italy, and Brazil. The embassies of Cuba, Lithuania, and Poland are still located in the Meridian Hill neighborhood, a bit further up 16th Street, the Embassy Building No. 10, built in the late 1920s, never served as an embassy despite being designed as one. A number of embassies are scattered south of Massachusetts Avenue and closer to the National Mall, notably those of Canada, Mexico, Spain, Saudi Arabia
7.
Observatory
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An observatory is a location used for observing terrestrial or celestial events. Astronomy, climatology/meteorology, geology, oceanography and volcanology are examples of disciplines for which observatories have been constructed, historically, observatories were as simple as containing an astronomical sextant or Stonehenge. Astronomical observatories are mainly divided into four categories, space based, airborne, ground based, ground-based observatories, located on the surface of Earth, are used to make observations in the radio and visible light portions of the electromagnetic spectrum. Most optical telescopes are housed within a dome or similar structure, Telescope domes have a slit or other opening in the roof that can be opened during observing, and closed when the telescope is not in use. In most cases, the upper portion of the telescope dome can be rotated to allow the instrument to observe different sections of the night sky. Radio telescopes usually do not have domes, for optical telescopes, most ground-based observatories are located far from major centers of population, to avoid the effects of light pollution. The ideal locations for modern observatories are sites that have dark skies, a percentage of clear nights per year, dry air. At high elevations, the Earths atmosphere is thinner, thereby minimizing the effects of atmospheric turbulence, sites that meet the above criteria for modern observatories include the southwestern United States, Hawaii, Canary Islands, the Andes, and high mountains in Mexico such as Sierra Negra. Major optical observatories include Mauna Kea Observatory and Kitt Peak National Observatory in the USA, Roque de los Muchachos Observatory in Spain, and Paranal Observatory in Chile. Specific research study performed in 2009 shows that the best possible location for ground-based observatory on Earth is Ridge A — a place in the part of Eastern Antarctica. This location provides the least atmospheric disturbances and best visibility, beginning in 1930s, radio telescopes have been built for use in the field of radio astronomy to observe the Universe in the radio portion of the electromagnetic spectrum. Since the mid-20th century, a number of observatories have been constructed at very high altitudes, above 4. The largest and most notable of these is the Mauna Kea Observatory, the Chacaltaya Astrophysical Observatory in Bolivia, at 5,230 m, was the worlds highest permanent astronomical observatory from the time of its construction during the 1940s until 2009. It has now surpassed by the new University of Tokyo Atacama Observatory. As a result, the resolution of space telescopes such as the Hubble Space Telescope is often much smaller than a ground-based telescope with a similar aperture. However, all these advantages do come with a price, Space telescopes are much more expensive to build than ground-based telescopes. Due to their location, space telescopes are also difficult to maintain. The Hubble Space Telescope was serviced by the Space Shuttle while many other space telescopes cannot be serviced at all, Airborne observatories have the advantage of height over ground installations, putting them above most of the Earths atmosphere
8.
Light pollution
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Light pollution, also known as photopollution, is excessive, misdirected or obtrusive artificial light. As a major side-effect of urbanization, it is blamed for compromising health, disrupting ecosystems, Light pollution is the adding-of/added light itself, in analogy to added sound, carbon dioxide, etc. Adverse consequences are multiple, some of them may not be known yet, scientific definitions thus include the following, The degradation of photic habitat by artificial light. The alteration of light levels in the outdoor environment owing to artificial light sources. The alteration of light levels in the environment due to man-made sources of light. Indoor light pollution is such alteration of light levels in the environment due to sources of light. The introduction by humans, directly or indirectly, of light into the environment. The first three of the four scientific definitions describe the state of the environment. The fourth one describes the process of polluting by light, Light pollution is a side effect of industrial civilization. Its sources include building exterior and interior lighting, advertising, commercial properties, offices, factories, streetlights, since the early 1980s, a global dark-sky movement has emerged, with concerned people campaigning to reduce the amount of light pollution. The International Dark-Sky Association is one non-profit advocacy group involved in this movement, several industry groups also recognize light pollution as an important issue. For example, the Institution of Lighting Engineers in the United Kingdom provides its members with information about light pollution, the problems it causes, and how to reduce its impact. Since not everyone is irritated by the same lighting sources, it is common for one persons light pollution to be light that is desirable for another. One example of this is found in advertising, when an advertiser wishes for particular lights to be bright and visible, other types of light pollution are more certain. For instance, light that crosses a property boundary and annoys a neighbor is generally wasted. Where objective measurement is desired, light levels can be quantified by field measurement or mathematical modeling, authorities have also taken a variety of measures for dealing with light pollution, depending on the interests, beliefs and understandings of the society involved. Measures range from doing nothing at all, to implementing strict laws, Light pollution is a broad term that refers to multiple problems, all of which are caused by inefficient, unappealing, or unnecessary use of artificial light. Specific categories of light pollution include light trespass, over-illumination, glare, light clutter, a single offending light source often falls into more than one of these categories
9.
Master clock
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A master clock is a precision clock that provides timing signals to synchronise slave clocks as part of a clock network. Networks of electric clocks connected by wires to a precision pendulum clock began to be used in institutions like factories, offices. In the days before the availability of highly accurate reference time many master clocks were an accurate electrically maintained pendulum clock. The devices driven could be wall clocks, tower clocks, factory sirens, school bells, small weights could also be added or removed manually in the absence of this mechanism again without interruption
10.
Atomic clock
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The principle of operation of an atomic clock is not based on nuclear physics, but rather on atomic physics, it uses the microwave signal that electrons in atoms emit when they change energy levels. Early atomic clocks were based on masers at room temperature, currently, the most accurate atomic clocks first cool the atoms to near absolute zero temperature by slowing them with lasers and probing them in atomic fountains in a microwave-filled cavity. An example of this is the NIST-F1 atomic clock, one of the primary time. The accuracy of an atomic clock depends on two factors, the first factor is temperature of the sample atoms—colder atoms move much more slowly, allowing longer probe times. The second factor is the frequency and intrinsic width of the electronic transition, higher frequencies and narrow lines increase the precision. National standards agencies in many countries maintain a network of atomic clocks which are intercompared and these clocks collectively define a continuous and stable time scale, International Atomic Time. For civil time, another time scale is disseminated, Coordinated Universal Time, UTC is derived from TAI, but approximately synchronised, by using leap seconds, to UT1, which is based on actual rotation of the Earth with respect to the solar time. The idea of using atomic transitions to measure time was suggested by Lord Kelvin in 1879, magnetic resonance, developed in the 1930s by Isidor Rabi, became the practical method for doing this. In 1945, Rabi first publicly suggested that atomic beam magnetic resonance might be used as the basis of a clock, the first atomic clock was an ammonia maser device built in 1949 at the U. S. National Bureau of Standards. It was less accurate than existing quartz clocks, but served to demonstrate the concept, calibration of the caesium standard atomic clock was carried out by the use of the astronomical time scale ephemeris time. This led to the agreed definition of the latest SI second being based on atomic time. Equality of the ET second with the SI second has been verified to within 1 part in 1010, the SI second thus inherits the effect of decisions by the original designers of the ephemeris time scale, determining the length of the ET second. Since the beginning of development in the 1950s, atomic clocks have been based on the transitions in hydrogen-1, caesium-133. The first commercial atomic clock was the Atomichron, manufactured by the National Company, more than 50 were sold between 1956 and 1960. This bulky and expensive instrument was replaced by much smaller rack-mountable devices, such as the Hewlett-Packard model 5060 caesium frequency standard. In August 2004, NIST scientists demonstrated a chip-scale atomic clock, according to the researchers, the clock was believed to be one-hundredth the size of any other. It requires no more than 125 mW, making it suitable for battery-driven applications and this technology became available commercially in 2011. Ion trap experimental optical clocks are more precise than the current caesium standard, in March 2017, NASA plans to deploy the Deep Space Atomic Clock, a miniaturized, ultra-precise mercury-ion atomic clock, into outer space
11.
GPS satellite blocks
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A GPS satellite is a satellite used by the NAVSTAR Global Positioning System. The first satellite in the system, Navstar 1, was launched February 22,1978, the GPS satellite constellation is operated by the 50th Space Wing of the United States Air Force. The GPS satellites circle the Earth at an altitude of about 20,000 km, Rockwell International was awarded a contract in 1974 to build the first eight Block I satellites. In 1978 the contract was extended to build an additional three Block I satellites, beginning with Navstar 1 in 1978, ten Block I GPS satellites were successfully launched. One satellite, Navstar 7, was lost due to a launch on 18 December 1981. The Block I satellites were launched from Vandenberg Air Force Base using Atlas rockets that were converted intercontinental ballistic missiles, the satellites were built by Rockwell International at the same plant in Seal Beach, CA where the S-II second stages of the Saturn V rockets had been built. The Block I series consisted of the concept validation satellites and reflected various stages of system development, lessons learned from the 11 satellites in the series were incorporated into the fully operational Block II series. Dual solar arrays supplied over 400 watts of power, charging NiCd batteries for operations in Earths shadow, s-band communications were used for control and telemetry, while a UHF channel provided cross-links between spacecraft. A hydrazine propulsion system was used for orbital correction, the payload included two L-band navigation signals at 1575.42 MHz and 1227.60 MHz. The final Block I launch was conducted on 9 October 1985, the Block II satellites were the first full scale operational GPS satellites, designed to provide 14 days of operation without any contact from the control segment. The prime contractor was Rockwell International, which built a SVN12 qualification vehicle after an amendment to the Block I contract, in 1983 the company was awarded an additional contract to build 28 Block II/IIA satellites. Block II spacecraft were 3-axis stabilized, with ground pointing using reaction wheels, two solar arrays supplied 710 watts of power, while S band communications were used for control and telemetry. A UHF channel was use for cross-links between spacecraft, a hydrazine propulsion system was used for orbital correction. The payload included two L band navigation signals at 1575.42 MHz and 1227.60 MHz, each spacecraft carried 2 rubidium and 2 cesium clocks, as well as nuclear detonation detection sensors, leading to a mass of 1,660 kilograms. The first of the nine satellites in the initial Block II series was launched February 14,1989, the final satellite of the series to be taken out of service was decommissioned on March 15,2007, well past its 7.5 year design life. The Block IIA satellites were slightly improved versions of the Block II series, however, the mass increased to 1,816 kilograms Nineteen satellites in the Block IIA series were launched, the first on November 26,1990 and the last on November 6,1997. The final satellite of the Block IIA series was decommissioned on January 25,2016, the Block IIR series are replenishment satellites developed by Lockheed Martin. Each satellite weighs 4,480 pounds at launch and 2,370 pounds once on orbit, the first attempted launch of a Block IIR satellite failed on January 17,1997 when the Delta II rocket exploded 12 seconds into flight
12.
United States Air Force
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The United States Air Force is the aerial warfare service branch of the United States Armed Forces and one of the seven American uniformed services. Initially part of the United States Army, the USAF was formed as a branch of the military on 18 September 1947 under the National Security Act of 1947. It is the most recent branch of the U. S. military to be formed, the U. S. Air Force is a military service organized within the Department of the Air Force, one of the three military departments of the Department of Defense. The Air Force is headed by the civilian Secretary of the Air Force, who reports to the Secretary of Defense, the U. S. Air Force provides air support for surface forces and aids in the recovery of troops in the field. As of 2015, the service more than 5,137 military aircraft,406 ICBMs and 63 military satellites. It has a $161 billion budget with 313,242 active duty personnel,141,197 civilian employees,69,200 Air Force Reserve personnel, and 105,500 Air National Guard personnel. According to the National Security Act of 1947, which created the USAF and it shall be organized, trained, and equipped primarily for prompt and sustained offensive and defensive air operations. The stated mission of the USAF today is to fly, fight, and win in air, space and we will provide compelling air, space, and cyber capabilities for use by the combatant commanders. We will excel as stewards of all Air Force resources in service to the American people, while providing precise and reliable Global Vigilance, Reach and it should be emphasized that the core functions, by themselves, are not doctrinal constructs. The purpose of Nuclear Deterrence Operations is to operate, maintain, in the event deterrence fails, the US should be able to appropriately respond with nuclear options. Dissuading others from acquiring or proliferating WMD, and the means to deliver them, moreover, different deterrence strategies are required to deter various adversaries, whether they are a nation state, or non-state/transnational actor. Nuclear strike is the ability of forces to rapidly and accurately strike targets which the enemy holds dear in a devastating manner. Should deterrence fail, the President may authorize a precise, tailored response to terminate the conflict at the lowest possible level, post-conflict, regeneration of a credible nuclear deterrent capability will deter further aggression. Finally, the Air Force regularly exercises and evaluates all aspects of operations to ensure high levels of performance. Nuclear surety ensures the safety, security and effectiveness of nuclear operations, the Air Force, in conjunction with other entities within the Departments of Defense or Energy, achieves a high standard of protection through a stringent nuclear surety program. The Air Force continues to pursue safe, secure and effective nuclear weapons consistent with operational requirements, adversaries, allies, and the American people must be highly confident of the Air Forces ability to secure nuclear weapons from accidents, theft, loss, and accidental or unauthorized use. This day-to-day commitment to precise and reliable nuclear operations is the cornerstone of the credibility of the NDO mission, positive nuclear command, control, communications, effective nuclear weapons security, and robust combat support are essential to the overall NDO function. OCA is the method of countering air and missile threats, since it attempts to defeat the enemy closer to its source
13.
Very-long-baseline interferometry
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Very-long-baseline interferometry is a type of astronomical interferometry used in radio astronomy. In VLBI a signal from a radio source, such as a quasar, is collected at multiple radio telescopes on Earth. The distance between the telescopes is then calculated using the time difference between the arrivals of the radio signal at different telescopes. This allows observations of an object that are made simultaneously by many radio telescopes to be combined, Data received at each antenna in the array include arrival times from a local atomic clock, such as a hydrogen maser. At a later time, the data are correlated with data from other antennas that recorded the same radio signal, the resolution achievable using interferometry is proportional to the observing frequency. VLBI is most well known for imaging distant cosmic radio sources, spacecraft tracking, using VLBI in this manner requires large numbers of time difference measurements from distant sources observed with a global network of antennas over a period of time. Some of the results derived from VLBI include, High resolution radio imaging of cosmic radio sources. Variations in the Earths orientation and length of day, the most sensitive VLBI array in the world is the European VLBI Network. This is an array which brings together the largest European radiotelescopes for typically week-long sessions. The combination of the EVN and VLBA is known as Global VLBI, VLBI has traditionally operated by recording the signal at each telescope on magnetic tapes or disks, and shipping those to the correlation center for replay. Recently, it has become possible to connect VLBI radio telescopes in close to real-time, while employing the local time references of the VLBI technique. The image to the shows the first science produced by the European VLBI Network using e-VLBI. The data from 6 telescopes were processed in time at the European Data Processing centre at JIVE. The Netherlands Academic Research Network SURFnet provides 6 x 1 Gbit/s connectivity between JIVE and the GEANT2 network, in the quest for even greater angular resolution, dedicated VLBI satellites have been placed in Earth orbit to provide greatly extended baselines. Experiments incorporating such space-borne array elements are termed Space Very Long Baseline Interferometry, another space VLBI mission, Spektr-R, was launched in July 2011. In VLBI interferometry, the digitized antenna data are recorded at each of the telescopes. The antenna signal is sampled with a precise and stable atomic clock that is additionally locked onto a GPS time standard. Alongside the astronomical data samples, the output of this clock is recorded on the tape/disk media, the recorded media are then transported to a central location
14.
Quasar
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A quasar is an active galactic nucleus of very high luminosity. A quasar consists of a black hole surrounded by an orbiting accretion disk of gas. As gas in the accretion disk falls toward the black hole, quasars emit energy across the electromagnetic spectrum and can be observed at radio, infrared, visible, ultraviolet, and X-ray wavelengths. The most powerful quasars have luminosities exceeding 1041 W, thousands of greater than the luminosity of a large galaxy such as the Milky Way. Quasars are found over a broad range of distances. The peak epoch of quasar activity in the Universe corresponds to redshifts around 2, as of 2011, the most distant known quasar is at redshift z=7.085, light observed from this quasar was emitted when the Universe was only 770 million years old. Because quasars are distant objects, any light which reaches the Earth is redshifted due to the expansion of space. In early optical images, quasars appeared as point sources, indistinguishable from stars, with infrared telescopes and the Hubble Space Telescope, the host galaxies surrounding the quasars have been detected in some cases. These galaxies are normally too dim to be seen against the glare of the quasar, most quasars, with the exception of 3C273 whose average apparent magnitude is 12.9, cannot be seen with small telescopes. The luminosity of some quasars changes rapidly in the optical range, because these changes occur very rapidly they define an upper limit on the volume of a quasar, quasars are not much larger than the Solar System. This implies a high power density. The mechanism of brightness changes probably involves relativistic beaming of astrophysical jets pointed nearly directly toward Earth, the highest redshift quasar known is ULAS J1120+0641, with a redshift of 7.085, which corresponds to a comoving distance of approximately 29 billion light-years from Earth. Since light cannot escape the black holes, the energy is actually generated outside the event horizon by gravitational stresses. Central masses of 105 to 109 solar masses have been measured in quasars by using reverberation mapping. The matter accreting onto the hole is unlikely to fall directly in. Quasars may also be ignited or re-ignited when normal galaxies merge, in fact, it has been suggested that a quasar could form as the Andromeda Galaxy collides with our own Milky Way galaxy in approximately 3–5 billion years. More than 200,000 quasars are known, most from the Sloan Digital Sky Survey, all observed quasar spectra have redshifts between 0.056 and 7.085. Applying Hubbles law to these redshifts, it can be shown that they are between 600 million and 28.85 billion light-years away
15.
Vice President of the United States
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The executive power of both the vice president and the president is granted under Article Two, Section One of the Constitution. The vice president is elected, together with the president. The Office of the Vice President of the United States assists, as the president of the United States Senate, the vice president votes only when it is necessary to break a tie. Additionally, pursuant to the Twelfth Amendment, the president presides over the joint session of Congress when it convenes to count the vote of the Electoral College. Currently, the president is usually seen as an integral part of a presidents administration. The Constitution does not expressly assign the office to any one branch, causing a dispute among scholars whether it belongs to the executive branch, the legislative branch, or both. The modern view of the president as a member of the executive branch is due in part to the assignment of executive duties to the vice president by either the president or Congress. Mike Pence of Indiana is the 48th and current vice president and he assumed office on January 20,2017. The formation of the office of vice president resulted directly from the compromise reached at the Philadelphia Convention which created the Electoral College, the delegates at Philadelphia agreed that each state would receive a number of presidential electors equal to the sum of that states allocation of Representatives and Senators. The delegates assumed that electors would typically choose to favor any candidate from their state over candidates from other states, under a plurality election process, this would tend to result in electing candidates solely from the largest states. Consequently, the delegates agreed that presidents must be elected by a majority of the number of electors. To guard against such stratagems, the Philadelphia delegates specified that the first runner-up presidential candidate would become vice president, the process for selecting the vice president was later modified in the Twelfth Amendment. Each elector still receives two votes, but now one of those votes is for president, while the other is for vice president. The requirement that one of those votes be cast for a candidate not from the electors own state remains in effect. S, other statutorily granted roles include membership of both the National Security Council and the Board of Regents of the Smithsonian Institution. As President of the Senate, the president has two primary duties, to cast a vote in the event of a Senate deadlock and to preside over. For example, in the first half of 2001, the Senators were divided 50-50 between Republicans and Democrats and Dick Cheneys tie-breaking vote gave the Republicans the Senate majority, as President of the Senate, the vice president oversees procedural matters and may cast a tie-breaking vote. As President of the Senate, John Adams cast 29 tie-breaking votes that was surpassed by John C. Calhoun with 31. Adamss votes protected the presidents sole authority over the removal of appointees, influenced the location of the national capital, on at least one occasion Adams persuaded senators to vote against legislation he opposed, and he frequently addressed the Senate on procedural and policy matters
16.
John Quincy Adams
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John Quincy Adams was an American statesman who served as a diplomat, United States Senator, member of the House of Representatives, and was the sixth President of the United States from 1825 to 1829. He was a member of the Federalist, Democratic-Republican, National Republican and he was the son of President John Adams and Abigail Adams and thus contributed to the formation of the Adams political family. Adams shaped U. S. foreign policy using his ardently nationalist commitment to U. S. republican values, as a diplomat, Adams played an important role in negotiating key treaties, most notably the Treaty of Ghent, which ended the War of 1812. As Secretary of State, he negotiated with Britain over the United States northern border with Canada, negotiated with Spain the annexation of Florida, historians generally concur that he was one of the greatest diplomats and secretaries of state in American history. Adams was elected president in a close and controversial four-way contest in 1824, as president he sought to modernize the American economy and promote education. Adams enacted a part of his agenda and paid off much of the national debt, however he was stymied time and again by a Congress controlled by opponents, and his lack of patronage networks helped politicians sabotage him. He lost his 1828 bid for re-election to Andrew Jackson, after leaving office, he was elected as U. S. Representative from Massachusetts in 1830, serving for the last 17 years of his life with greater acclaim than he had achieved as president, animated by his growing revulsion against slavery, Adams became a leading opponent of the Slave Power. Adams predicted the Unions dissolution over slavery, and in such a case, historians have in the aggregate ranked Adams as the 21st most successful president. John Quincy Adams was born on July 11,1767, to John Adams and he was named for his mothers maternal grandfather, Colonel John Quincy, after whom Quincy, Massachusetts, is named. Young Adams was educated by private tutors – his cousin James Thaxter and his fathers law clerk and he soon began to exhibit his literary skills in 1779, when he initiated a diary which he kept until just before he died in 1848. The diary comprised an unprecedented fifty volumes, representing one of the most extensive, much of Adams youth was spent accompanying his father overseas. He accompanied his father on diplomatic missions to France from 1778 until 1779, Adams acquired an education at institutions such as Leiden University. He matriculated in Leiden on January 10,1781, for nearly three years, beginning at the age of 14, he accompanied Francis Dana as a secretary on a mission to Saint Petersburg, Russia, to obtain recognition of the new United States. He spent time in Finland, Sweden, and Denmark and, in 1804, during these years overseas, Adams became fluent in French and Dutch and became familiar with German and other European languages. Though Adams enjoyed Europe, he and his family decided he needed to return to the United States to complete his education and he entered Harvard College, graduated in 1787 with a Bachelor of Arts degree, and was elected by Phi Beta Kappa. Adams, mainly with the influence of his father, had excelled in studies and reached fluency in Latin. Upon entering Harvard he had already translated Virgil, Horace, Plutarch, after graduating from Harvard, he studied law with Theophilus Parsons in Newburyport, Massachusetts from 1787 to 1789
17.
United States Secretary of the Navy
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The Secretary of the Navy is a statutory office and the head of the Department of the Navy, a military department within the Department of Defense of the United States of America. The Department of the Navy consists of two Uniformed Services, the United States Navy and the United States Marine Corps. In effect, all authority within the Navy and Marine Corps, specifically enumerated responsibilities of the SECNAV in beforementioned section are, recruiting, organizing, supplying, equipping, training, mobilizing, and demobilizing. The Secretary also oversees the construction, outfitting, and repair of ships, equipment. The Secretary of the Navy is a member of the Defense Acquisition Board, chaired by the Under Secretary of Defense for Acquisition, Technology, the CNO and the Commandant act as the principal executive agents of the SECNAV within their respective services to implement the orders of the Secretary. The United States Navy Regulations is the principal regulatory document of the Department of the Navy, the Chief of Naval Operations and the Commandant of the Marine Corps have their own separate staffs, the Office of the Chief of Naval Operations and Headquarters Marine Corps
18.
John Branch
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Branch was born in Halifax County, North Carolina, on November 4,1782, the son of wealthy landowners. Educated at the University of North Carolina, where he was a member of the Philanthropic Society, he occupied himself as a planter, Branch served in the North Carolina Senate from 1811 to 1817 and was the states Governor from 1817 to 1820. After further service in the state Senate, he represented North Carolina in the United States Senate from 1823 until 1829 and was a supporter of Andrew Jackson. When Jackson became President, he selected Branch as his Secretary of the Navy, in that post, Branch promoted several reforms in the Navys policies and administration, many of which were not implemented until years later. He reduced the resources going to the construction of new ships, Branch also sent the frigate USS Potomac to the Far East to punish the murderers of a U. S. merchant ships crew and to generally promote and protect American commerce in the region. John Branch resigned as Secretary in 1831, during the Petticoat affair, which involved the social ostracism of Margaret ONeill Eaton, Eaton by a group of Cabinet members and their wives led by Floride Calhoun, the wife of Vice President John C. Later that year, Branch was elected to the U. S. House of Representatives as a Jacksonian, in the mid-1830s, he moved to Leon County, Florida, where he lived for much of the next decade-and-a-half on his Live Oak Plantation. In 1844, President John Tyler appointed him Floridas territorial governor until the 1845 election of a governor under the state constitution, Branch returned to North Carolina in the early 1850s, remaining there until his death on January 4,1863. Branch is buried in Elmwood Cemetery in Enfield, North Carolina, Branch was an uncle of the Confederate General Lawrence OBryan Branch. American National Biography Dictionary of American Biography Buccellato, Robert, raleigh, NC, Commercial Printing Co.1915 Hoffmann, William S. John Branch and the Origins of the Whig Party in North Carolina. Biographical Directory of the United States Congress John Branch at Find a Grave
19.
Louis M. Goldsborough
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Louis Malesherbes Goldsborough was a rear admiral in the United States Navy during the American Civil War. He held several sea commands during the Civil War, including that of the North Atlantic Blockading Squadron and he was also noted for contributions to nautical scientific research. His younger brother, John R. Goldsborough, was also a U. S. Navy officer who served during the Civil War and who later became a commodore. Louis Malesherbes Goldsborough was born in Washington, D. C in 1805 and he was appointed midshipman in the United States Navy by Secretary of the Navy Paul Hamilton on June 28,1812. At the time of his appointment, he was seven years old, and Goldsborough did not actually begin serving until February 13,1816, in 1831 Goldsborough married Elizabeth Wirt, daughter of William Wirt, U. S. Attorney General from 1817-1829. Together, they had three children, William, Louis, and Elizabeth, during the Aegean Anti-Piracy Campaign, Goldsborough led a four-boat night expedition from Porpoise in October 1827 to rescue British merchant brig Comet from Mediterranean pirates. In 1830 he was appointed first officer in charge of the newly created Depot of Charts and Instruments at Washington, Goldsborough suggested creation of the depot and initiated the collection and centralization of the instruments, books and charts that were scattered among several Navy yards. After two years he was relieved by Lieutenant Charles Wilkes, after cruising the Pacific in the frigate United States, he participated in the bombardment of Veracruz in Ohio during the Mexican-American War. Goldsborough was given command of the Atlantic Blockading Squadron in September 1861, Goldsborough refused to be placed under McClellans direct command, telling Assistant Secretary of the Navy Gustavus Vasa Fox that he would instead cooperate with McClellan. At the start of the Seven Days Battles, Goldsborough was asked again and this move, coupled with newspaper accounts critical of the Navy, so seriously hurt Goldsborough that he requested that he be relieved. He was promoted to Rear Admiral in August 1862, and in September passed command of the squadron to Acting Rear Admiral Samuel Phillips Lee, Goldsborough would finish the war performing administrative duties in Washington, D. C. In June 1865, Goldsborough became the first commander of the European Squadron, in 1868, Goldsborough returned to Washington and took command of the Washington Navy Yard, a position he held until he retired in 1873. Rear Admiral Louis M. Goldsborough died on February 20,1877, the United States Navy has named three ships USS Goldsborough in honor of Admiral Goldsborough. List of Superintendents of the United States Naval Academy This article incorporates text from the public domain Dictionary of American Naval Fighting Ships
20.
James Melville Gilliss
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James Melville Gilliss was an astronomer, United States Navy officer and founder of the United States Naval Observatory. His parents were George and Mary Gillis and he joined the navy in 1827 as a midshipman at the age of 15 and he served on the Delaware, the Java, and the Concord. In 1831, after an examination, was advanced to passed midshipman, in 1831 he started his studies at the University of Virginia, and went to Paris for further studies one year later. He got the position of an assistant at the Depot of Charts and Instruments in Washington in 1836 and he was also responsible for astronomical observations. He made a research journey under Captain Charles Wilkes in 1837. He made observations on the differences of longitude by means of moon-culminations, made meteorological observations, Gilliss was made a lieutenant in 1838. Naval Observatory although the latter was used less until a bill was passed clarifying what it would be officially called, until that point every item, every document and letter had to be duplicated because of the two names of National Observatory and Navy Observatory. This was but another time consuming duty that came to Matthew Fontaine Maury who headed the observatory from its beginning until 1861, another of the many duties of superintendent M. F. Maury during this time period was to oversee all publications that embraced every maritime survey. F. Maurys plans for charting the seas for the safety, when Maury resigned to serve his state, his home, kin and friends. Lieutenant Gillis was then placed in charge of observatory and he had previously been placed in charge of obtaining the instruments needed and books that were to be used in the observatory. It would be the first national observatory in the U. S. But Gillis had failed in overseeing the building and placing of instruments. Thus all had to be removed while the building itself was repaired, Gillis was assigned elsewhere and became the second superintendent of this observatory lasting from 1861 until his death in 1865 - only four years total as opposed to Maurys long time there. USNS James M. Gilliss, a research ship launched 1962. Astronomy and Astrophysics National Historic Landmark Theme Study, a Brief Biography of Lieutenant Gilliss. Dick, Steven J. Sky and Ocean Joined, The US Naval Observatory 1830-2000, Memoir of James Melville Gilliss 1811-1865. Biographical Memoirs of the National Academy of Sciences, sterling, Keir B. ed. Gilliss, James Melville. Biographical Dictionary of American and Canadian Naturalists and Environmentalists, encyclopædia Britannica U. S. Navy Library Document of Liberty named after him National Academy of Sciences Biographical Memoir
21.
Marine chronometer
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A marine chronometer is a timepiece that is precise and accurate enough to be used as a portable time standard, it can therefore be used to determine longitude by means of celestial navigation. Timepieces made in Switzerland may display the word chronometer only if certified by the COSC, to determine a position on the Earths surface, it is necessary and sufficient to know the latitude, longitude, and altitude. Altitude considerations can, of course, be ignored for vessels operating at sea level, until the mid-1750s, accurate navigation at sea out of sight of land was an unsolved problem due to the difficulty in calculating longitude. Navigators could determine their latitude by measuring the angle at noon or, in the Northern Hemisphere. To find their longitude, however, they needed a standard that would work aboard a ship. Observation of regular celestial motions, such as Galileos method based on observing Jupiters natural satellites, was not possible at sea due to the ships motion. The lunar distances method, initially proposed by Johannes Werner in 1514, was developed in parallel with the marine chronometer, the Dutch scientist Gemma Frisius was the first to propose the use of a chronometer to determine longitude in 1530. The purpose of a chronometer is to measure accurately the time of a fixed location. This is particularly important for navigation, knowing GMT at local noon allows a navigator to use the time difference between the ships position and the Greenwich Meridian to determine the ships longitude. The creation of a timepiece which would work reliably at sea was difficult, christiaan Huygens, following his invention of the pendulum clock in 1656, made the first attempt at a marine chronometer in 1673 in France, under the sponsorship of Jean-Baptiste Colbert. He obtained a patent for his invention from Colbert, but his clock remained imprecise at sea, the first published use of the term was in 1684 in Arcanum Navarchicum, a theoretical work by Kiel professor Matthias Wasmuth. This was followed by a theoretical description of a chronometer in works published by English scientist William Derham in 1713. Attempts to construct a marine chronometer were begun by Jeremy Thacker in England in 1714. In 1714, the British government offered a prize for a method of determining longitude at sea. His first two sea timepieces H1 and H2 used this system, but he realised that they had a sensitivity to centrifugal force. However, H3s circular balances still proved too inaccurate and he abandoned the large machines. Harrison solved the problems with his much smaller H4 chronometer design in 1761. H4 looked much like a large five-inch diameter pocket watch, in 1761, Harrison submitted H4 for the £20,000 longitude prize
22.
Calibration
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Calibration in measurement technology and metrology is the comparison of measurement values delivered by a device under test with those of a calibration standard of known accuracy. Such a standard could be another measurement device of known accuracy, strictly, the term calibration means just the act of comparison, and does not include any subsequent adjustment. The calibration standard is normally traceable to a national standard held by a National Metrological Institute and this definition states that the calibration process is purely a comparison, but introduces the concept of Measurement uncertainty in relating the accuracies of the device under test and the standard. The increasing need for accuracy and uncertainty and the need to have consistent. In many countries a National Metrology Institute will exist which will maintain primary standards of measurement which will be used to provide traceability to customers instruments by calibration. The NMI supports the metrological infrastructure in that country by establishing an unbroken chain, examples of National Metrology Institutes are NPL in the UK, NIST in the United States, PTB in Germany and many others. This may be done by national standards laboratories operated by the government or by private firms offering metrology services, quality management systems call for an effective metrology system which includes formal, periodic, and documented calibration of all measuring instruments. ISO9000 and ISO17025 standards require that these actions are to a high level. To communicate the quality of a calibration the calibration value is often accompanied by a traceable uncertainty statement to a confidence level. This is evaluated through careful uncertainty analysis, some times a DFS is required to operate machinery in a degraded state. Whenever this does happen, it must be in writing and authorized by a manager with the assistance of a calibration technician. Measuring devices and instruments are categorized according to the quantities they are designed to measure. These vary internationally, e. g. NIST 150-2G in the U. S. the standard instrument for each test device varies accordingly, e. g. a dead weight tester for pressure gauge calibration and a dry block temperature tester for temperature gauge calibration. g. This is the perception of the instruments end-user, however, very few instruments can be adjusted to exactly match the standards they are compared to. For the vast majority of calibrations, the process is actually the comparison of an unknown to a known. The calibration process begins with the design of the instrument that needs to be calibrated. The design has to be able to hold a calibration through its calibration interval, in other words, the design has to be capable of measurements that are within engineering tolerance when used within the stated environmental conditions over some reasonable period of time. Having a design with these characteristics increases the likelihood of the measuring instruments performing as expected
23.
Transit (astronomy)
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The word transit refers to cases where the nearer object appears considerably smaller than the more distant object. Cases where the object appears larger and completely hides the more distant object are known as occultations. One example of a transit involves the motion of a planet between an observer and the Sun. This can happen only with inferior planets, namely Mercury and Venus, however, as seen from outer planets such as Mars, the Earth itself transits the Sun on occasion. The term can also be used to describe the motion of a satellite across its parent planet, for one of the Galilean satellites across Jupiter. A transit requires three bodies to be lined up in a single line, more rare are cases where four bodies are lined up. The one closest to the present occurred on 27 June 1586, when Mercury transited the Sun as seen from Venus at the time as a transit of Mercury from Saturn. In recent years the discovery of planets has excited interest in the possibility of detecting their transits across their own stellar primaries. HD 209458b is the first such transiting planet to be discovered, in rare cases, one planet can pass in front of another. If the nearer planet appears smaller than the distant one. During a transit there are four contacts, when the circumference of the circle touches the circumference of the large circle at a single point. Historically, measuring the time of each point of contact was one of the most accurate ways to determine the positions of astronomical bodies. No missions were planned to coincide with the transit of Earth visible from Mars on 11 May 1984, consequently, the next opportunity to observe such an alignment will be in 2084. On December 21,2012, the Cassini–Huygens probe, in orbit around Saturn, on 3 June 2014, the Mars rover Curiosity observed the planet Mercury transiting the Sun, marking the first time a planetary transit has been observed from a celestial body besides Earth. 1989, ISBN 0-943396-25-5 Jean Meeus, Astronomical Tables of the Sun, Moon,1995, ISBN 0-943396-45-X Karl Ramsayer, Geodätische Astronomie, Vol. 2a of Handbuch der Vermessungskunde,900 p. J. B. Metzler, Stuttgart 1969
24.
Star
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It is primarily present in steroid-producing cells, including theca cells and luteal cells in the ovary, Leydig cells in the testis and cell types in the adrenal cortex. The aqueous phase between two membranes cannot be crossed by the lipophilic cholesterol, unless certain proteins assist in this process. It is now clear that this process is mediated by the action of StAR. The mechanism by which StAR causes cholesterol movement remains unclear as it appears to act from the outside of the mitochondria, some involve StAR transferring cholesterol itself like a shuttle. Another notion is that it causes cholesterol to be kicked out of the membrane to the inner. StAR may also promote the formation of contact sites between the outer and inner mitochondrial membranes to allow cholesterol influx, another suggests that StAR acts in conjunction with PBR, causing the movement of Cl− out of the mitochondria to facilitate contact site formation. However, evidence for an interaction between StAR and PBR remains elusive, in humans, the gene for StAR is located on chromosome 8p11.2 and the protein has 285 amino acids. The signal sequence of StAR that targets it to the mitochondria is clipped off in two steps with import into the mitochondria, phosphorylation at the serine at position 195 increases its activity. The domain of StAR important for promoting cholesterol transfer is the StAR-related transfer domain, StAR is the prototypic member of the START domain family of proteins and is thus also known as STARD1 for START domain-containing protein 1. It is hypothesized that the START domain forms a pocket in StAR that binds single cholesterol molecules for delivery to P450scc, the closest homolog to StAR is MLN64. Together they comprise the StarD1/D3 subfamily of START domain-containing proteins, StAR is a mitochondrial protein that is rapidly synthesized in response to stimulation of the cell to produce steroid. Hormones that stimulate its production depend on the type and include luteinizing hormone, ACTH. At the cellular level, StAR is synthesized typically in response to activation of the second messenger system. StAR has thus far found in all tissues that can produce steroids, including the adrenal cortex, the gonads, the brain. One known exception is the human placenta, mutations in the gene for StAR cause lipoid congenital adrenal hyperplasia, in which patients produce little steroid and can die shortly after birth. Mutations that less severely affect the function of StAR result in nonclassic lipoid CAH or familial glucocorticoid deficiency type 3, all known mutations disrupt StAR function by altering its START domain. In the case of StAR mutation, the phenotype does not present until birth since human placental steroidogenesis is independent of StAR. At the cellular level, the lack of StAR results in an accumulation of lipid within cells
25.
Meridian (astronomy)
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In astronomy, the meridian is the great circle passing through the celestial poles, the zenith, and the nadir of an observers location. Consequently, it also the horizons north and south points. A celestial meridian matches the projection of a terrestrial meridian onto the celestial sphere, hence, the number of astronomical meridians are infinite. There are several ways in which the meridian can be divided into semicircles, in one way, it is divided into the local meridian and the antimeridian. The former semicircle contains the zenith and is terminated by the celestial poles, in the horizontal coordinate system the meridian is divided into halves terminated by the horizons north and south points. The upper meridian passes through the zenith, and the lower meridian, a celestial object will appear to drift past the local meridian as the Earth spins, for the meridian is fixed to the local horizon. At culmination, the object reaches its highest point in the sky when crossing, or transiting, using an objects right ascension and the local sidereal time it is possible to determine the time of its culmination. The term meridian comes from the Latin meridies, which means both midday and south, meridian Prime meridian Longitude Millar, William. The Amateur Astronomers Introduction to the Celestial Sphere
26.
Foggy Bottom
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Foggy Bottom is one of the oldest late 18th and 19th-century neighborhoods in Washington, D. C. Much of Foggy Bottom is occupied by the campus of George Washington University. Foggy Bottom is thought to have received its due to its riverside location, which made it susceptible to concentrations of fog and industrial smoke. The United States Department of State gained the metonym Foggy Bottom when it moved its headquarters to the nearby Harry S Truman Building in 1947, the settlement officially was named Hamburgh, but colloquially was called Funkstown. In 1765, German settlers established the town of Hamburg on what would become the area between 24th and 18th NW Street, jacob Funk, the recorded founder of Hamburg, allegedly bought the land and divided it into 287 lots of land. There are reportedly two more founders, Robert Peter and James Linigan, the three had control of the land until 1791 when the territories were given to the city of Washington and the United States government. In the town of Hamburg, a German community was founded by many German immigrants, in 1768, Funk sold two lots of territory to both the German Lutheran and the German Presbyterian communities. The lot that was sold to the German Lutherans was located on the corner of 20th, the lot sold to the German Presbyterians was located on the southeast corner of 22nd and G Street. The Lutheran lot would not be in use until 1833 and the Presbyterian until the 1880s, the lot that was sold to the German Lutheran community was turned into the Concordia German Church. By the 19th century, Foggy Bottom became a community of white and black laborers employed at the breweries, glass plants. These industrial facilities are also cited as a reason for the neighborhoods name. Foggy Bottom attracted few settlers until the 1850s, when more industrial enterprises came into the area, Funk also set aside land in Hamburgh for a German-speaking congregation in 1768. Concordia German Evangelical Church, located at 1920 G Street NW was finally founded in 1833, today the congregation is The United Church, and is the oldest religious community remaining in Foggy Bottom. Foggy Bottom became the site of the George Washington Universitys 42-acre main campus in 1912, Foggy Bottom was also the name of a line of beer by the Olde Heurich Brewing Company, which was founded by German immigrant Christian Heurichs grandson, Gary Heurich. He tried to revive the tradition of his familys Christian Heurich Brewing Company, Christian Heurich Brewing Companys most successful products bore such local names as Senate and Old Georgetown. During the 1950s, Heurich Brewing also sponsored the professional baseball team. Industry consolidation led the brewery to cease operations in 1956, in 1961–1962, the brewery buildings were razed to make way for the John F. Kennedy Center for the Performing Arts. Although the firm was founded in the Foggy Bottom neighborhood, the beer was brewed in Utica
27.
Lincoln Memorial
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The Lincoln Memorial is an American national monument built to honor the 16th President of the United States, Abraham Lincoln. It is located on the end of the National Mall in Washington. Dedicated in 1922, it is one of several built to honor an American president. It has always been a major tourist attraction and since the 1930s has been a symbolic center focused on race relations and it has been listed on the National Register of Historic Places since October 15,1966. It is open to the public 24 hours a day, in 2007, it was ranked seventh on the List of Americas Favorite Architecture by the American Institute of Architects. Since 2010, approximately 6 million people visit the memorial annually, the first public memorial to Abraham Lincoln in Washington, D. C. was a statue by Lot Flannery erected in front of the District of Columbia City Hall in 1868, three years after Lincolns assassination. Demands for a national memorial had been voiced since the time of Lincolns death. In 1867, Congress passed the first of many bills incorporating a commission to erect a monument for the sixteenth president, an American sculptor, Clark Mills, was chosen to design the monument. Subscriptions for the project were insufficient, the first five bills, proposed in the years 1901,1902, and 1908, met with defeat because of opposition from Speaker Joe Cannon. The sixth bill, introduced on December 13,1910, passed, the Lincoln Memorial Commission had its first meeting the following year and U. S. President William H. Taft was chosen as the commissions president. Progress continued at a pace and by 1913 Congress had approved of the Commissions choice of design. There were questions regarding the commissions plan, many thought that architect Henry Bacons Greek temple design was far too ostentatious for a man of Lincolns humble character. Instead they proposed a simple log cabin shrine, the site too did not go unopposed. The recently reclaimed land in West Potomac Park was seen by many to be too swampy or too inaccessible. Other sites, such as Union Station, were put forth, furthermore, the Potomac Park site had already been designated in the McMillan Plan of 1901 to be the location of a future monument comparable to that of the Washington Monument. With Congressional approval and a $300,000 allocation, the project got underway, on February 12,1914, a dedication ceremony was conducted and the following month the actual construction began. Work progressed steadily according to schedule, some changes were made to the plan. The statue of Lincoln, originally designed to be 10 feet tall, was enlarged to 19 feet to prevent it from being overwhelmed by the huge chamber
28.
White House
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The White House is the official residence and principal workplace of the President of the United States, located at 1600 Pennsylvania Avenue NW in Washington, D. C. It has been the residence of every U. S. president since John Adams in 1800, the term White House is often used to refer to actions of the president and his advisers, as in The White House announced that. The residence was designed by Irish-born architect James Hoban in the Neoclassical style, construction took place between 1792 and 1800 using Aquia Creek sandstone painted white. When Thomas Jefferson moved into the house in 1801, he added low colonnades on each wing that concealed stables and storage. In 1814, during the War of 1812, the mansion was set ablaze by the British Army in the Burning of Washington, destroying the interior, reconstruction began almost immediately, and President James Monroe moved into the partially reconstructed Executive Residence in October 1817. Exterior construction continued with the addition of the semi-circular South portico in 1824, because of crowding within the executive mansion itself, President Theodore Roosevelt had all work offices relocated to the newly constructed West Wing in 1901. Eight years later in 1909, President William Howard Taft expanded the West Wing and created the first Oval Office, in the main mansion, the third-floor attic was converted to living quarters in 1927 by augmenting the existing hip roof with long shed dormers. A newly constructed East Wing was used as an area for social events. East Wing alterations were completed in 1946, creating additional office space, by 1948, the houses load-bearing exterior walls and internal wood beams were found to be close to failure. Under Harry S. Truman, the rooms were completely dismantled. Once this work was completed, the rooms were rebuilt. The Executive Residence is made up of six stories—the Ground Floor, State Floor, Second Floor, the property is a National Heritage Site owned by the National Park Service and is part of the Presidents Park. In 2007, it was ranked second on the American Institute of Architects list of Americas Favorite Architecture, in May 1790, New York began construction of Government House for his official residence, but he never occupied it. The national capital moved to Philadelphia in December 1790, the July 1790 Residence Act named Philadelphia, Pennsylvania the temporary national capital for a 10-year period while the Federal City was under construction. The City of Philadelphia rented Robert Morriss city house at 190 High Street for Washingtons presidential residence, the first president occupied the Market Street mansion from November 1790 to March 1797, and altered it in ways that may have influenced the design of the White House. As part of an effort to have Philadelphia named the permanent national capital, Pennsylvania built a much grander presidential mansion several blocks away. President John Adams also occupied the Market Street mansion from March 1797 to May 1800, on Saturday, November 1,1800, he became the first president to occupy the White House. The Presidents House in Philadelphia became a hotel and was demolished in 1832, the Presidents House was a major feature of Pierre Charles LEnfants plan for the newly established federal city, Washington, D. C
29.
Old Naval Observatory
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Old Naval Observatory is a historic site in Northwest, Washington, D. C. The Washington meridian of 1850 passes through the Observatory, the observatory operated from 1844 to 1893 when it was closed in favor of a new U. S. Naval Observatory facility on Massachusetts Avenue. The building and grounds were retained by the U. S. Navy and it was declared a National Historic Landmark in 1965. The facility housed the Navys Bureau of Medicine and Surgery until 2012, the grounds and observatory are closed to the public. The entire Navy Hill is being transferred to the United States Department of State due to Base Realignment and Closure, and the Navy will be moving out. The Central Intelligence Agencys forerunner, the Office of Strategic Services was a tenant on the Hill during World War II, in 2014, the Department of State began expanding into the Navy Hill. DC-341, Old Naval Observatory, Twenty-Third & E Streets Northwest, Washington, District of Columbia, DC,2 photos,2 data pages,1 photo caption page
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Massachusetts Avenue (Washington, D.C.)
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Massachusetts Avenue is a major diagonal transverse road in Washington, D. C. and the Massachusetts Avenue Historic District is a historic district that includes part of it. Appearing in Peter Charles LEnfants original plan, Massachusetts Avenue crosses three of Washingtons four quadrants and it intersects every major north–south street and passes numerous Washington landmarks. It is a landmark itself, long considered the boundary of the downtown as well as home of Washingtons Embassy Row. Massachusetts Avenue is tied with Pennsylvania Avenue as the widest road in the District, the two roads run in parallel through much of the city, Massachusetts about seven blocks north of Pennsylvania. Massachusetts Avenue was long Washingtons premier residential street, as Pennsylvania was once its most sought-after business address, both streets were named after states with prominent roles in the American Revolution. The historic district is an 81-acre area that includes 150 contributing buildings and 3 contributing structures and it was listed on the National Register of Historic Places in 1985. It includes multiple properties that are listed on the National Register. The main section of Massachusetts Avenue begins at 19th Street Southeast, just to the west of the former District of Columbia General Hospital site, at elevation with respect to the hospital, Massachusetts Avenue commands a view of the Anacostia River. It proceeds in a northwesterly direction crosstown, at Lincoln Park the road enters Northeast D. C. and the neighborhood of Capitol Hill. In the tradition of the acronym SoHo, realtors sometimes give this area the moniker NoMa and it intersects with Interstate 395 at H Street NW, and passes over Mount Vernon Square in front of the Walter E. Washington Convention Center. Massachusetts Avenue passes through the ring of Dupont Circle and curves north at Sheridan Circle. After crossing Rock Creek over the Charles C, the Washington National Cathedral, located at the intersection of Mass and Wisconsin Avenues, is usually considered the end of Embassy Row. At Ward Circle, Massachusetts delineates the American University Park neighborhood from Spring Valley and it crosses the Washington-Montgomery County, Maryland border at Westmoreland Circle. In Maryland, the road signed as State Highway 396. Another section of Massachusetts Avenue, discontinuous from the one described above and that section extends from 30th Street SE near District of Columbia Route 295, to Southern Avenue SE at the border between D. C. and Prince Georges County. Nitze School of Advanced International Studies, the Brookings Institution, the Peterson Institute, St. Nicholas Cathedral, numerous embassies and residences are listed on the National Register of Historic Places, and the National Trust for Historic Preservation makes its home on Massachusetts Avenue. The track of the avenue was not paved until the administration of Alexander Robey Shepherd in the early 1870s and it was extended beyond Boundary Road in the 1880s, and beyond Rock Creek up to the District line after 1900. Residential development along Massachusetts Avenue accelerated in the 1870s, mostly around the circles located west of 9th Street NW and these brick and brownstone structures reflected the Queen Anne, Richardsonian Romanesque, and Château styles in vogue at the time
31.
National Register of Historic Places
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The National Register of Historic Places is the United States federal governments official list of districts, sites, buildings, structures, and objects deemed worthy of preservation. The passage of the National Historic Preservation Act in 1966 established the National Register, of the more than one million properties on the National Register,80,000 are listed individually. The remainder are contributing resources within historic districts, each year approximately 30,000 properties are added to the National Register as part of districts or by individual listings. For most of its history the National Register has been administered by the National Park Service and its goals are to help property owners and interest groups, such as the National Trust for Historic Preservation, coordinate, identify, and protect historic sites in the United States. While National Register listings are mostly symbolic, their recognition of significance provides some financial incentive to owners of listed properties, protection of the property is not guaranteed. During the nomination process, the property is evaluated in terms of the four criteria for inclusion on the National Register of Historic Places, the application of those criteria has been the subject of criticism by academics of history and preservation, as well as the public and politicians. Occasionally, historic sites outside the proper, but associated with the United States are also listed. Properties can be nominated in a variety of forms, including individual properties, historic districts, the Register categorizes general listings into one of five types of properties, district, site, structure, building, or object. National Register Historic Districts are defined geographical areas consisting of contributing and non-contributing properties, some properties are added automatically to the National Register when they become administered by the National Park Service. These include National Historic Landmarks, National Historic Sites, National Historical Parks, National Military Parks/Battlefields, National Memorials, on October 15,1966, the Historic Preservation Act created the National Register of Historic Places and the corresponding State Historic Preservation Offices. Initially, the National Register consisted of the National Historic Landmarks designated before the Registers creation, approval of the act, which was amended in 1980 and 1992, represented the first time the United States had a broad-based historic preservation policy. To administer the newly created National Register of Historic Places, the National Park Service of the U. S. Department of the Interior, hartzog, Jr. established an administrative division named the Office of Archeology and Historic Preservation. Hartzog charged OAHP with creating the National Register program mandated by the 1966 law, ernest Connally was the Offices first director. Within OAHP new divisions were created to deal with the National Register, the first official Keeper of the Register was William J. Murtagh, an architectural historian. During the Registers earliest years in the late 1960s and early 1970s, organization was lax and SHPOs were small, understaffed, and underfunded. A few years later in 1979, the NPS history programs affiliated with both the U. S. National Parks system and the National Register were categorized formally into two Assistant Directorates. Established were the Assistant Directorate for Archeology and Historic Preservation and the Assistant Directorate for Park Historic Preservation, from 1978 until 1981, the main agency for the National Register was the Heritage Conservation and Recreation Service of the United States Department of the Interior. In February 1983, the two assistant directorates were merged to promote efficiency and recognize the interdependency of their programs, jerry L. Rogers was selected to direct this newly merged associate directorate
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Matthew Fontaine Maury
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Matthew Fontaine Maury, United States Navy, was an American astronomer, historian, oceanographer, meteorologist, cartographer, author, geologist, and educator, LL. D. Maury made many important new contributions to charting winds and ocean currents, in 1825 at age 19, Maury obtained, through the then-US Congressman Sam Houston, a midshipmans warrant in the United States Navy. As a midshipman on board the frigate USS Brandywine, almost immediately he began to study the seas and record methods of navigation. When a leg injury left him unfit for sea duty, Maury devoted his time to the study of navigation, meteorology, winds and he became Superintendent of the U. S. Naval Observatory and head of the Depot of Charts and Instruments. Here, Maury studied thousands of logs and charts. He published the Wind and Current Chart of the North Atlantic, Maurys uniform system of recording oceanographic data was adopted by navies and merchant marines around the world and was used to develop charts for all the major trade routes. With the outbreak of the Civil War, Maury, a Virginian, resigned his commission as a US Navy commander and he spent the war in the South, as well as abroad in Great Britain, Ireland, and France. He helped acquire a ship, CSS Georgia, for the Confederacy while also advocating stopping the war in America among several European Nations, following the war, Maury accepted a teaching position at the Virginia Military Institute in Lexington, Virginia. He died at his V. M. I. home in Lexington in 1873 after completing an exhausting lecture tour on national and international weather forecasting on land. He had also completed his book on his Geological Survey of Virginia, Maury was a descendant of a prominent Virginia family of Huguenot ancestry whose ancestry can be traced back to 15th century France. Matthew Fontaine Maurys grandfather was a teacher to a future U. S. president. Maury also had Dutch-American ancestry from the Minor family of early Virginia, M. F. Maury was born in 1806 in Spotsylvania County, Virginia near the City of Fredericksburg, his parents were Richard Maury and Diane Minor Maury. The family moved to Franklin, Tennessee, when he was age five and he wanted to emulate the naval career of his older brother, Flag Lieutenant John Minor Maury, who however caught yellow fever after fighting pirates as an officer in the United States Navy. As a result of Johns painful death, Matthew Maurys father, Richard, Maury joined the Navy as a midshipman on board the frigate Brandywine which was carrying the Marquis de La Fayette home to France following the Marquis famous visit to the United States. Almost immediately, Maury began to study the seas and record methods of navigation, one of the experiences that piqued this interest was a circumnavigation of the globe on the USS Vincennes, his assigned ship and the first US warship to travel around the world. Matthew Maurys seagoing days came to an end at the age of 33 after a stagecoach accident broke his right leg. Maury had known of the Psalms of David since childhood, John Minor, Mary, Walker, Matilda, Betsy, Richard Launcelot, Matthew Fontaine, Catherine, and Charles. His Bible is depicted on his monument beside his left leg, the product of his work was international recognition and the publication in 1847 of Wind and Current Chart of the North Atlantic
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Vulcanization
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These additives modify the polymer by forming cross-links between individual polymer chains. Vulcanized materials are less sticky and have mechanical properties. The term vulcanized fiber refers to cellulose that has treated in a zinc chloride solution to cross-link the cellulose fibers. Today, a vast array of products are made with vulcanized rubber, including tires, shoe soles, hoses, although vulcanization is a nineteenth-century invention, the history of rubber cured by other means goes back to prehistoric times. The name of the first major civilization in Guatemala and Mexico, ancient Mesoamericans, spanning from ancient Olmecs to Aztecs, extracted latex from Castilla elastica, a type of rubber tree in the area. The juice of a vine, Ipomoea alba, was then mixed with this latex to create processed rubber as early as 1600 BC. In the Western world, rubber remained a curiosity, although it was used to produce waterproofed products, in 1832-1834 Nathaniel Hayward and Friedrich Ludersdorf discovered that rubber treated with sulfur lost all its viscosity. It is likely Hayward shared his discovery with Goodyear, possibly inspiring him to make the discovery of vulcanisation, thomas Hancock, a scientist and engineer, was the first to patent vulcanization of rubber. He was awarded a British patent on May 21,1845, three weeks later, on June 15,1845, Charles Goodyear was awarded a patent in the United States. Goodyear claimed that he had discovered earlier, in 1839. He wrote the story of the discovery in 1853 in his autobiographical book Gum-Elastica, here is Goodyears account of the invention, taken from Gum-Elastica. Although the book is an autobiography, Goodyear chose to write it in the person so that the inventor. He describes the scene in a factory where his brother worked. The inventor made experiments to ascertain the effect of heat on the compound that had decomposed in the mail-bags. He was surprised to find that the specimen, being brought into contact with a hot stove. Goodyear goes on to describe how his discovery was not readily accepted, upon further trial with heat, he was further convinced of the correctness of this inference, by finding that the India rubber could not be melted in boiling sulfur at any heat, but always charred. He made another trial of heating a similar fabric before an open fire, the same effect, that of charring the gum, followed. There were further indications of success in producing the desired result, as upon the edge of the charred portion appeared a line or border, that was not charred, but perfectly cured
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Time ball
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Time ball or timeball or ball time is an obsolete time-signalling device. Accurate timekeeping is essential to the determination of longitude at sea, although the use of time balls has been replaced by electronic time signals, some time balls have remained operational as historical tourist attractions. The fall of a ball was in antiquity a way to show to people the time. Ancient Greek clocks had this system in the square of a city, as in the city of Gaza inpost Alexander era. Time ball stations set their clocks according to observations of the positions of the sun. Originally they either had to be stationed at the observatory, or had to keep an accurate clock at the station which was set manually to observatory time. Following the introduction of the electric telegraph around 1850, time balls could be located at a distance from their source of mean time, the first time ball was erected at Portsmouth, England, in 1829 by its inventor Robert Wauchope, a captain in the Royal Navy. Others followed in the ports of the United Kingdom and around the maritime world. One was installed in 1833 at the Greenwich Observatory in London by the Astronomer Royal, John Pond, Wauchope submitted his scheme to American and French ambassadors when they visited England. The United States Naval Observatory was established in Washington, D. C. Time balls were usually dropped at 1 p. m. They were raised half way about 5 minutes earlier to alert the ships, the time was recorded when the ball began descending, not when it reached the bottom. With the commencement of radio signals, time balls gradually became obsolete. Rather than the ball being dropped rapidly with its used as the time signal. The Lyttelton Timeball Station in Lyttelton, New Zealand, was operational until it was damaged in the 2010 Canterbury earthquake, in November 2012, a large financial donation was made available to contribute towards rebuilding the tower, a project the community considered. On 25 May 2013, it was announced that the tower and ball would be restored, today there are over sixty time balls standing, though many of these are no longer operational. Index to the House Documents, Otherwise Publ. as Executive Documents, list of time balls worldwide in 1876. Time ball/cannon hobbyist Time ball and cannon Association
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Charles Goodyear
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Goodyear is credited with inventing the chemical process to create and manufacture pliable, waterproof, moldable rubber. However, the Mesoamericans used stabilized rubber for balls and other objects as early as 1600 BC, Goodyears discovery of the vulcanization process followed five years of searching for a more stable rubber and stumbling upon the effectiveness of heating after Thomas Hancock. His discovery initiated decades of successful rubber manufacturing in the Lower Naugatuck Valley in Connecticut, as rubber was adopted to multiple applications, including footwear, the The Goodyear Tire & Rubber Company is named after him. Charles Goodyear was born in New Haven, Connecticut, the son of Amasa Goodyear, and his father was a descendant of Stephen Goodyear of London, Middlesex, England, one of the founders of the colony of New Haven in 1638. In 1814, Charles left his home and went to Philadelphia to learn the hardware business, on August 3,1824 he married Clarissa Beecher. Two years later the moved to Philadelphia, and there Charles Goodyear opened a hardware store. This is where he did most of his work and this continued to increase until it seemed that he was to be a wealthy man. Between 1829 and 1830 he broke down in health, being troubled with dyspepsia, at the same time, the failure of a number of business endeavors seriously embarrassed his firm. They struggled on, however, for time, but were finally obliged to fail. Between the years 1831 and 1832, Goodyear heard about gum elastic, the Roxbury Rubber Company, of Boston, had been for some time experimenting with the gum, and believed it had found means for manufacturing goods from it. It had a plant and was sending its goods all over the country. It was some of Roxburys goods that first attracted Goodyears attention, soon after this, Goodyear visited New York, and his attention went to life preservers, and it struck him that the tube used for inflation was not very effective nor well-made. Therefore, upon returning to Philadelphia, he made tubes and brought back to New York. The manager was pleased with the ingenuity that Goodyear had shown in manufacturing the tubes. He confessed to Goodyear that the business was on the verge of ruin, to their surprise, thousands of US$ worth of goods that they had determined to be of good quality were being returned, the gum having rotted, making them useless. Goodyear at once made up his mind to experiment on this gum, however, when he returned to Philadelphia, a creditor had him arrested and imprisoned. While there, he tried his first experiments with India rubber, the first thing that he made was shoes, and he used his own house for grinding, calendering and vulcanizing, with the help of his wife and children. His compound at this time consisted of India rubber, lampblack, and magnesia and it was not long, however, before he discovered that the gum, even treated this way, became sticky
36.
Telegraphy
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Telegraphy is the long-distance transmission of textual or symbolic messages without the physical exchange of an object bearing the message. Thus semaphore is a method of telegraphy, whereas pigeon post is not, telegraphy requires that the method used for encoding the message be known to both sender and receiver. Such methods are designed according to the limits of the medium used. The use of signals, beacons, reflected light signals. In the 19th century, the harnessing of electricity led to the invention of electrical telegraphy, the advent of radio in the early 20th century brought about radiotelegraphy and other forms of wireless telegraphy. The word telegraph was first coined by the French inventor of the Semaphore line, Claude Chappe, a telegraph is a device for transmitting and receiving messages over long distances, i. e. for telegraphy. The word telegraph alone now generally refers to an electrical telegraph, Wireless telegraphy is also known as CW, for continuous wave, as opposed to the earlier radio technique of using a spark gap. Contrary to the definition used by Chappe, Morse argued that the term telegraph can strictly be applied only to systems that transmit. This is to be distinguished from semaphore, which transmits messages. Smoke signals, for instance, are to be considered semaphore, according to Morse, telegraph dates only from 1832 when Pavel Schilling invented one of the earliest electrical telegraphs. A telegraph message sent by a telegraph operator or telegrapher using Morse code was known as a telegram. A cablegram was a sent by a submarine telegraph cable. Later, a Telex was a sent by a Telex network. A wire picture or wire photo was a picture that was sent from a remote location by a facsimile telegraph. A diplomatic telegram, also known as a cable, is the term given to a confidential communication between a diplomatic mission and the foreign ministry of its parent country. These continue to be called telegrams or cables regardless of the used for transmission. Commercial electrical telegraphs were introduced from 1837, the first telegraphs came in the form of optical telegraph, including the use of smoke signals, beacons, or reflected light, which have existed since ancient times. Early proposals for a telegraph system were made to the Royal Society by Robert Hooke in 1684 and were first implemented on an experimental level by Sir Richard Lovell Edgeworth in 1767
37.
Western Union
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The Western Union Company is an American financial services and communications company. Its North American headquarters is in Meridian, Colorado, though the designation of nearby Englewood is used in its mailing address. Up until it discontinued the service in 2006, Western Union was the best-known U. S. company in the business of exchanging telegrams, Western Union has several divisions, with products such as person-to-person money transfer, money orders, business payments and commercial services. They offered standard Cablegrams, as well as more products such as Candygrams, Dollygrams. Western Union, as a monopoly, dominated the telegraph industry in the late 19th century. It was the first communications empire and set a pattern for American-style communications businesses as they are known today, meanwhile, Ezra Cornell had bought back one of his bankrupt companies and renamed it the New York & Western Union Telegraph Company. Originally fierce competitors, by 1856 both groups were convinced that consolidation was their only alternative for progress. The merged company was named the Western Union Telegraph Company at Cornells insistence, Western Union bought out smaller companies rapidly, and by 1860 its lines reached from the East Coast to the Mississippi River, and from the Great Lakes to the Ohio River. In 1861 it opened the first transcontinental telegraph, in 1865 it formed the Russian–American Telegraph in an attempt to link America to Europe, via Alaska, into Siberia, to Moscow. The company enjoyed phenomenal growth during the few years. Under the leadership of presidents Jeptha Wade and William Orton its capitalization rose from $385,700 in 1858 to $41 million in 1876. However it was top-heavy with stock issues, and faced growing competition from several firms, in 1881 Gould took control of Western Union. It introduced the first stock ticker in 1866, and a time service in 1870. The next year,1871, the company introduced its money transfer service, in 1879, Western Union left the telephone business, having lost a patent lawsuit with Bell Telephone Company. As the telephone replaced the telegraph, money transfer would become its primary business, when the Dow Jones Transportation Average stock market index for the New York Stock Exchange was created in 1884, Western Union was one of the original eleven all-American companies tracked. By 1900, Western Union operated a million miles of telegraph lines, the company continued to grow, acquiring more than 500 smaller competitors. Its monopoly power was almost complete in 1943 when it bought Postal Telegraph, in 1914, Western Union offered the first charge card for consumers, in 1923 it introduced teletypewriters to join its branches. Singing telegrams followed in 1933, intercity fax in 1935, in 1958, it began offering Telex service to customers in New York City
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Wireless
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Wireless communication, or sometimes simply wireless, is the transfer of information or power between two or more points that are not connected by an electrical conductor. The most common wireless technologies use radio waves, with radio waves distances can be short, such as a few meters for television or as far as thousands or even millions of kilometers for deep-space radio communications. It encompasses various types of fixed, mobile, and portable applications, including radios, cellular telephones, personal digital assistants. Somewhat less common methods of achieving wireless communications include the use of other wireless technologies, such as light, magnetic. The term wireless has been used twice in history, with slightly different meaning. It was initially used from about 1890 for the first radio transmitting and receiving technology, as in wireless telegraphy and this became its primary usage in the 2000s, due to the advent of technologies such as LTE, LTE-Advanced, Wi-Fi and Bluetooth. Wireless operations permit services, such as communications, that are impossible or impractical to implement with the use of wires. The term is used in the telecommunications industry to refer to telecommunications systems which use some form of energy to transfer information without the use of wires. Information is transferred in this manner over both short and long distances, similar to free-space optical communication, the photophone also required a clear line of sight between its transmitter and its receiver. It would be decades before the photophones principles found their first practical applications in military communications. Marconi soon developed a system that was transmitting signals way beyond distances anyone could have predicted, guglielmo Marconi and Karl Ferdinand Braun were awarded the 1909 Nobel Prize for Physics for their contribution to this form of wireless telegraphy. Free space means the light travel through the open air or outer space. This contrasts with other technologies that use light beams traveling through transmission lines such as optical fiber or dielectric light pipes. The technology is useful where physical connections are due to high costs or other considerations. Sonic, especially ultrasonic short range communication involves the transmission and reception of sound, electromagnetic induction has short range communication and power. This has been used in situations such as pacemakers, as well as for short-range Rfid tags. Common examples of wireless equipment include, Infrared and ultrasonic remote control devices Professional LMR and SMR typically used by business, industrial, consumer Two-way radio including FRS Family Radio Service, GMRS and Citizens band radios. Consumer and professional Marine VHF radios, airband and radio navigation equipment used by aviators and air traffic control Cellular telephones and pagers, provide connectivity for portable and mobile applications, both personal and business
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Cambridge, Massachusetts
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Cambridge is a city in Middlesex County, Massachusetts, and is a part of the Boston metropolitan area. According to the 2010 Census, the population was 105,162. As of July 2014, it was the fifth most populous city in the state, behind Boston, Worcester, Springfield, Cambridge was one of the two seats of Middlesex County prior to the abolition of county government in 1997, Lowell was the other. The site for what would become Cambridge was chosen in December 1630, because it was located safely upriver from Boston Harbor, Thomas Dudley, his daughter Anne Bradstreet, and her husband Simon, were among the first settlers of the town. The first houses were built in the spring of 1631, the settlement was initially referred to as the newe towne. Official Massachusetts records show the name capitalized as Newe Towne by 1632, the original village site is in the heart of todays Harvard Square. In the late 19th century, various schemes for annexing Cambridge itself to the city of Boston were pursued and rejected, in 1636, the Newe College was founded by the colony to train ministers. Newe Towne was chosen for the site of the college by the Great and General Court primarily—according to Cotton Mather—to be near the popular, in May 1638 the name of the settlement was changed to Cambridge in honor of the university in Cambridge, England. Hooker and Shepard, Newtownes ministers, and the colleges first president, major benefactor, in 1629, Winthrop had led the signing of the founding document of the city of Boston, which was known as the Cambridge Agreement, after the university. It was Governor Thomas Dudley who, in 1650, signed the charter creating the corporation which still governs Harvard College, Cambridge grew slowly as an agricultural village eight miles by road from Boston, the capital of the colony. By the American Revolution, most residents lived near the Common and Harvard College, with farms and estates comprising most of the town. Coming up from Virginia, George Washington took command of the volunteer American soldiers camped on Cambridge Common on July 3,1775, most of the Tory estates were confiscated after the Revolution. On January 24,1776, Henry Knox arrived with artillery captured from Fort Ticonderoga, a second bridge, the Canal Bridge, opened in 1809 alongside the new Middlesex Canal. The new bridges and roads made what were formerly estates and marshland into prime industrial and residential districts, in the mid-19th century, Cambridge was the center of a literary revolution when it gave the country a new identity through poetry and literature. Cambridge was home to some of the famous Fireside Poets—so called because their poems would often be read aloud by families in front of their evening fires, the Fireside Poets—Henry Wadsworth Longfellow, James Russell Lowell, and Oliver Wendell Holmes—were highly popular and influential in their day. Cambridge was incorporated as a city in 1846, the citys commercial center began to shift from Harvard Square to Central Square, which became the downtown of the city around this time. The coming of the railroad to North Cambridge and Northwest Cambridge then led to three changes in the city, the development of massive brickyards and brickworks between Massachusetts Ave. For many decades, the citys largest employer was the New England Glass Company, by the middle of the 19th century it was the largest and most modern glassworks in the world
40.
Astronomical unit
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The astronomical unit is a unit of length, roughly the distance from Earth to the Sun. However, that varies as Earth orbits the Sun, from a maximum to a minimum. Originally conceived as the average of Earths aphelion and perihelion, it is now defined as exactly 149597870700 metres, the astronomical unit is used primarily as a convenient yardstick for measuring distances within the Solar System or around other stars. However, it is also a component in the definition of another unit of astronomical length. A variety of symbols and abbreviations have been in use for the astronomical unit. In a 1976 resolution, the International Astronomical Union used the symbol A for the astronomical unit, in 2006, the International Bureau of Weights and Measures recommended ua as the symbol for the unit. In 2012, the IAU, noting that various symbols are presently in use for the astronomical unit, in the 2014 revision of the SI Brochure, the BIPM used the unit symbol au. In ISO 80000-3, the symbol of the unit is ua. Earths orbit around the Sun is an ellipse, the semi-major axis of this ellipse is defined to be half of the straight line segment that joins the aphelion and perihelion. The centre of the sun lies on this line segment. In addition, it mapped out exactly the largest straight-line distance that Earth traverses over the course of a year, knowing Earths shift and a stars shift enabled the stars distance to be calculated. But all measurements are subject to some degree of error or uncertainty, improvements in precision have always been a key to improving astronomical understanding. Improving measurements were continually checked and cross-checked by means of our understanding of the laws of celestial mechanics, the expected positions and distances of objects at an established time are calculated from these laws, and assembled into a collection of data called an ephemeris. NASAs Jet Propulsion Laboratory provides one of several ephemeris computation services, in 1976, in order to establish a yet more precise measure for the astronomical unit, the IAU formally adopted a new definition. Equivalently, by definition, one AU is the radius of an unperturbed circular Newtonian orbit about the sun of a particle having infinitesimal mass. As with all measurements, these rely on measuring the time taken for photons to be reflected from an object. However, for precision the calculations require adjustment for such as the motions of the probe. In addition, the measurement of the time itself must be translated to a scale that accounts for relativistic time dilation
41.
Arithmetic mean
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In mathematics and statistics, the arithmetic mean, or simply the mean or average when the context is clear, is the sum of a collection of numbers divided by the number of numbers in the collection. The collection is often a set of results of an experiment, the term arithmetic mean is preferred in some contexts in mathematics and statistics because it helps distinguish it from other means, such as the geometric mean and the harmonic mean. In addition to mathematics and statistics, the mean is used frequently in fields such as economics, sociology, and history. For example, per capita income is the average income of a nations population. While the arithmetic mean is used to report central tendencies, it is not a robust statistic. In a more obscure usage, any sequence of values that form a sequence between two numbers x and y can be called arithmetic means between x and y. The arithmetic mean is the most commonly used and readily understood measure of central tendency, in statistics, the term average refers to any of the measures of central tendency. The arithmetic mean is defined as being equal to the sum of the values of each. For example, let us consider the monthly salary of 10 employees of a firm,2500,2700,2400,2300,2550,2650,2750,2450,2600,2400. The arithmetic mean is 2500 +2700 +2400 +2300 +2550 +2650 +2750 +2450 +2600 +240010 =2530, If the data set is a statistical population, then the mean of that population is called the population mean. If the data set is a sample, we call the statistic resulting from this calculation a sample mean. The arithmetic mean of a variable is denoted by a bar, for example as in x ¯. The arithmetic mean has several properties that make it useful, especially as a measure of central tendency and these include, If numbers x 1, …, x n have mean x ¯, then + ⋯ + =0. The mean is the single number for which the residuals sum to zero. If the arithmetic mean of a population of numbers is desired, the arithmetic mean may be contrasted with the median. The median is defined such that half the values are larger than, and half are smaller than, If elements in the sample data increase arithmetically, when placed in some order, then the median and arithmetic average are equal. For example, consider the data sample 1,2,3,4, the average is 2.5, as is the median. However, when we consider a sample that cannot be arranged so as to increase arithmetically, such as 1,2,4,8,16, in this case, the arithmetic average is 6.2 and the median is 4
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Transit of Venus
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A transit of Venus across the Sun takes place when the planet Venus passes directly between the Sun and a superior planet, becoming visible against the solar disk. During a transit, Venus can be seen from Earth as a black disk moving across the face of the Sun. The duration of such transits is usually measured in hours, a transit is similar to a solar eclipse by the Moon. While the diameter of Venus is more than 3 times that of the Moon, Venus appears smaller, Transits of Venus are among the rarest of predictable astronomical phenomena. They occur in a pattern that repeats every 243 years. The periodicity is a reflection of the fact that the periods of Earth. The last transit of Venus was on 5 and 6 June 2012, and was the last Venus transit of the 21st century, the previous pair of transits were in December 1874 and December 1882. The next transits of Venus will be on 10–11 December 2117, Venus transits are historically of great scientific importance as they were used to gain the first realistic estimates of the size of the Solar System. Observations of the 1639 transit, combined with the principle of parallax, the 2012 transit provided scientists with a number of other research opportunities, particularly in the refinement of techniques to be used in the search for exoplanets. Venus, with an orbit inclined by 3. 4° relative to the Earths, although the inclination between these two orbital planes is only 3. 4°, Venus can be as far as 9. 6° from the Sun when viewed from the Earth at inferior conjunction. Since the angular diameter of the Sun is about half a degree, sequences of transits usually repeat every 243 years. After this period of time Venus and Earth have returned to nearly the same point in their respective orbits. During the Earths 243 sidereal orbital periods, which total 88,757.3 days, Venus completes 395 sidereal orbital periods of 224.701 days each and this period of time corresponds to 152 synodic periods of Venus. Prior to 1518, the pattern of transits was 8,113.5 and 121.5 years, the current pattern will continue until 2846, when it will be replaced by a pattern of 105.5,129.5 and 8 years. Thus, the 243-year cycle is relatively stable, but the number of transits, for instance, there is a series which ended in 541 BC, and the series which includes 2117 only started in AD1631. Ancient Indian, Greek, Egyptian, Babylonian and Chinese observers knew of Venus, the early Greek astronomers called Venus by two names—Hesperus the evening star and Phosphorus the morning star. Pythagoras is credited with realizing they were the same planet, there is no evidence that any of these cultures knew of the transits. Venus was important to ancient American civilizations, in particular for the Maya, who called it Noh Ek, the Great Star or Xux Ek, the Wasp Star, they embodied Venus in the form of the god Kukulkán
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Photographic plate
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Photographic plates preceded photographic film as a capture medium in photography. The light-sensitive emulsion of silver salts was coated on a plate, typically thinner than common window glass. Glass plates were far superior to film for research-quality imaging because they were stable and less likely to bend or distort. Early plates used the wet collodion process, the wet plate process was replaced late in the 19th century by gelatin dry plates. Glass plate photographic material largely faded from the market in the early years of the 20th century, as more convenient. Workshops on the use of glass plate photography as a medium or for artistic use are still being conducted. A number of observatories, including Harvard College and Sonneberg, maintain large archives of photographic plates, many solar system objects were discovered by using photographic plates, superseding earlier visual methods. Discovery of minor planets using photographic plates was pioneered by Max Wolf beginning with his discovery of 323 Brucia in 1891, the first natural satellite discovered using photographic plates was Phoebe in 1898. Glass-backed plates, rather than film, were used in astronomy because they do not shrink or deform noticeably in the development process or under environmental changes. Photographic plates were also an important tool in early high-energy physics, Photographic emulsions were originally coated on thin glass plates for imaging with electron microscopes, which provided a more rigid, stable and flatter plane compared to plastic films. Beginning in the 1970s, high-contrast, fine grain emulsions coated on thicker plastic films manufactured by Kodak, Ilford and these films have largely been replaced by digitally imaging technologies. The earliest flexible films of the late 1880s were sold for use in medium-format cameras. The plastic was not of high optical quality and tended to curl. Initially, a transparent plastic base was more expensive to produce than glass, quality was eventually improved, manufacturing costs came down, and most amateurs gladly abandoned plates for films. After large-format high quality cut films for professional photographers were introduced in the late 1910s, CCD cameras have several advantages over glass plates, including high efficiency, linear light response, and simplified image acquisition and processing. The manufacture of plates has been discontinued by Kodak, Agfa. In the realm of traditional photography, a number of historical process enthusiasts make their own wet or dry plates from raw materials. Several institutions have established archives to preserve photographic plates and prevent their valuable historical information from being lost, the emulsion on the plate can deteriorate
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Parallax
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The term is derived from the Greek word παράλλαξις, meaning alternation. Due to foreshortening, nearby objects have a larger parallax than more distant objects when observed from different positions, astronomers use the principle of parallax to measure distances to the closer stars. Here, the parallax is the semi-angle of inclination between two sight-lines to the star, as observed when the Earth is on opposite sides of the Sun in its orbit. Parallax also affects optical instruments such as rifle scopes, binoculars, microscopes, many animals, including humans, have two eyes with overlapping visual fields that use parallax to gain depth perception, this process is known as stereopsis. In computer vision the effect is used for stereo vision, and there is a device called a parallax rangefinder that uses it to find range. A simple everyday example of parallax can be seen in the dashboard of motor vehicles that use a needle-style speedometer gauge. When viewed from directly in front, the speed may show exactly 60, as the eyes of humans and other animals are in different positions on the head, they present different views simultaneously. This is the basis of stereopsis, the process by which the brain exploits the parallax due to the different views from the eye to gain depth perception, animals also use motion parallax, in which the animals move to gain different viewpoints. For example, pigeons bob their heads up and down to see depth, the motion parallax is exploited also in wiggle stereoscopy, computer graphics which provide depth cues through viewpoint-shifting animation rather than through binocular vision. Parallax arises due to change in viewpoint occurring due to motion of the observer, of the observed, what is essential is relative motion. By observing parallax, measuring angles, and using geometry, one can determine distance, astronomers also use the word parallax as a synonym for distance measurent by other methods, see parallax #Astronomy. In a geostatic model, the movement of the star would have to be taken as real with the star oscillating across the sky with respect to the background stars, the parsec is defined as the distance for which the annual parallax is 1 arcsecond. Annual parallax is measured by observing the position of a star at different times of the year as the Earth moves through its orbit. Measurement of annual parallax was the first reliable way to determine the distances to the closest stars, the first successful measurements of stellar parallax were made by Friedrich Bessel in 1838 for the star 61 Cygni using a heliometer. Stellar parallax remains the standard for calibrating other measurement methods, accurate calculations of distance based on stellar parallax require a measurement of the distance from the Earth to the Sun, now based on radar reflection off the surfaces of planets. The angles involved in these calculations are very small and thus difficult to measure, the nearest star to the Sun, Proxima Centauri, has a parallax of 0.7687 ±0.0003 arcsec. This angle is approximately that subtended by an object 2 centimeters in diameter located 5.3 kilometers away, the fact that stellar parallax was so small that it was unobservable at the time was used as the main scientific argument against heliocentrism during the early modern age. In 1989, the satellite Hipparcos was launched primarily for obtaining improved parallaxes and proper motions for over 100,000 nearby stars, increasing the reach of the method tenfold
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Moons of Mars
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The two moons of Mars are Phobos and Deimos. Both moons were discovered in 1877 by Asaph Hall and are named after the characters Phobos and Deimos who, in Greek mythology, accompanied their father Ares, god of war, Ares was known as Mars to the Romans. It is possible that Mars may have moons smaller than 50–100 meters, of the two moons, Phobos orbits closer to Mars with a semi-major axis of 9,377 km. Deimos orbits Mars with an axis of 23,460 km.5 hours. The actual orbital distances of Phobos and Deimos are 1.4 and 3.5 Martian diameters, and their respective orbital periods are 7.6 and 30.3 hours. In the 20th century, V. G. Perminov, a designer of early Soviet Mars and Venus spacecraft, speculated Swift found. Furthermore, as they had not yet discovered, it was reasoned that they must be small. This would lead Swift to making an accurate estimate of their orbital distances. In addition Swift could have helped in his calculations by his friend. Voltaires 1752 short story Micromégas, about an alien visitor to Earth, Voltaire was presumably influenced by Swift. In recognition of these predictions, two craters on Deimos are named Swift and Voltaire. Asaph Hall discovered Deimos on 12 August 1877 at about 07,48 UTC and Phobos on 18 August 1877, at the US Naval Observatory in Washington, at the time, he was deliberately searching for Martian moons. Hall had previously seen what appeared to be a Martian moon on 10 August, I had barely time to secure an observation of its position when fog from the River stopped the work. This was at half past two oclock on the night of the 11th, cloudy weather intervened for several days. On 15 August the weather looking more promising, I slept at the Observatory, the sky cleared off with a thunderstorm at 11 oclock and the search was resumed. I told him also to keep quiet as I did not wish anything said until the matter was beyond doubt and he said nothing, but the thing was too good to keep and I let it out myself. On 17 August while waiting and watching for the outer moon, the observations of the 17th and 18th put beyond doubt the character of these objects and the discovery was publicly announced by Admiral Rodgers. The telescope used for the discovery was the 26-inch refractor then located at Foggy Bottom, in 1893 the lens was remounted and put in a new dome, where it remains into the 21st century
