Population density is a measurement of population per unit area or unit volume. It is applied to living organisms, most of the time to humans, it is a key geographical term. In simple terms population density refers to the number of people living in an area per kilometer square. Population density is population divided by total land water volume, as appropriate. Low densities may lead to further reduced fertility; this is called the Allee effect after the scientist. Examples of the causes in low population densities include: Increased problems with locating sexual mates Increased inbreeding For humans, population density is the number of people per unit of area quoted per square kilometer or square mile; this may be calculated for a county, country, another territory or the entire world. The world's population is around 7,500,000,000 and Earth's total area is 510,000,000 square kilometers. Therefore, the worldwide human population density is around 7,500,000,000 ÷ 510,000,000 = 14.7 per km2. If only the Earth's land area of 150,000,000 km2 is taken into account human population density is 50 per km2.
This includes all continental and island land area, including Antarctica. If Antarctica is excluded population density rises to over 55 people per km2. However, over half of the Earth's land mass consists of areas inhospitable to human habitation, such as deserts and high mountains, population tends to cluster around seaports and fresh-water sources. Thus, this number by itself does not give any helpful measurement of human population density. Several of the most densely populated territories in the world are city-states and dependencies; these territories have a small area and a high urbanization level, with an economically specialized city population drawing on rural resources outside the area, illustrating the difference between high population density and overpopulation The potential to maintain the agricultural aspects of deserts is limited as there is not enough precipitation to support a sustainable land. The population in these areas are low. Therefore, cities in the Middle East, such as Dubai, have been increasing in population and infrastructure growth at a fast pace.
Cities with high population densities are, by some, considered to be overpopulated, though this will depend on factors like quality of housing and infrastructure and access to resources. Most of the most densely populated cities are in Southeast Asia, though Cairo and Lagos in Africa fall into this category. City population and area are, however dependent on the definition of "urban area" used: densities are invariably higher for the central city area than when suburban settlements and the intervening rural areas are included, as in the areas of agglomeration or metropolitan area, the latter sometimes including neighboring cities. For instance, Milwaukee has a greater population density when just the inner city is measured, the surrounding suburbs excluded. In comparison, based on a world population of seven billion, the world's inhabitants, as a loose crowd taking up ten square feet per person, would occupy a space a little larger than Delaware's land area; the Gaza Strip has a population density of 5,046 pop/km.
Although arithmetic density is the most common way of measuring population density, several other methods have been developed to provide a more accurate measure of population density over a specific area. Arithmetic density: The total number of people / area of land Physiological density: The total population / area of arable land Agricultural density: The total rural population / area of arable land Residential density: The number of people living in an urban area / area of residential land Urban density: The number of people inhabiting an urban area / total area of urban land Ecological optimum: The density of population that can be supported by the natural resources Demography Human geography Idealized population Optimum population Population genetics Population health Population momentum Population pyramid Rural transport problem Small population size Distance sampling List of population concern organizations List of countries by population density List of cities by population density List of city districts by population density List of English districts by population density List of European cities proper by population density List of United States cities by population density List of islands by population density List of U.
S. states by population density List of Australian suburbs by population density Selected Current and Historic City, Ward & Neighborhood Density Duncan Smith / UCL Centre for Advanced Spatial Analysis. "World Population Density". Exploratory map shows data from the Global Human Settlement Layer produced by the European Commission JRC and the CIESIN Columbia University
1940 United States Census
The Sixteenth United States Census, conducted by the Census Bureau, determined the resident population of the United States to be 132,164,569, an increase of 7.3 percent over the 1930 population of 123,202,624 people. The census date of record was April 1, 1940. A number of new questions were asked including where people were 5 years before, highest educational grade achieved, information about wages; this census introduced sampling techniques. Other innovations included a field test of the census in 1939; this was the first census in which every state had a population greater than 100,000. The 1940 census collected the following information: In addition, a sample of individuals were asked additional questions covering age at first marriage and other topics. Full documentation on the 1940 census, including census forms and a procedural history, is available from the Integrated Public Use Microdata Series. Following completion of the census, the original enumeration sheets were microfilmed; as required by Title 13 of the U.
S. Code, access to identifiable information from census records was restricted for 72 years. Non-personally identifiable information Microdata from the 1940 census is available through the Integrated Public Use Microdata Series. Aggregate data for small areas, together with electronic boundary files, can be downloaded from the National Historical Geographic Information System. On April 2, 2012—72 years after the census was taken—microfilmed images of the 1940 census enumeration sheets were released to the public by the National Archives and Records Administration; the records are indexed only by enumeration district upon initial release. Official 1940 census website 1940 Census Records from the U. S. National Archives and Records Administration 1940 Federal Population Census Videos, training videos for enumerators at the U. S. National Archives Selected Historical Decennial Census Population and Housing Counts from the U. S. Census Bureau Snow, Michael S. "Why the huge interest in the 1940 Census?"
CNN. Monday April 9, 2012. 1941 U. S Census Report Contains 1940 Census results 1940 Census Questions Hosted at CensusFinder.com
The Lockheed T-33 Shooting Star is a subsonic American jet trainer. It was produced by Lockheed and made its first flight in 1948; the T-33 was developed from the Lockheed P-80/F-80 starting as TP-80C/TF-80C in development designated T-33A. It was used by the U. S. Navy as TO-2 TV-2, after 1962, T-33B; the last operator of the T-33, the Bolivian Air Force, retired the type in July 2017, after 44 years of service. The T-33 was developed from the Lockheed P-80/F-80 by lengthening the fuselage by over three feet and adding a second seat and flight controls, it was designated as a variant of the P-80/F-80, the TP-80C/TF-80C. Design work on the Lockheed P-80 began in 1943 with the first flight on 8 January 1944. Following on the Bell P-59, the P-80 became the first jet fighter to enter full squadron service in the United States Army Air Forces; as more advanced jets entered service, the F-80 took on another role—training jet pilots. The two-place T-33 jet was designed for training pilots qualified to fly propeller-driven aircraft.
Designated the TF-80C, the T-33 made its first flight on 22 March 1948 with Lockheed test pilot Tony LeVier at the controls. Production at Lockheed ran from 1948 to 1959; the US Navy used the T-33 as a land-based trainer starting in 1949. It was designated the TV-2, but was redesignated the T-33B in 1962; the Navy operated some ex-USAF P-80Cs as the TO-1, changed to the TV-1 about a year later. A carrier-capable version of the P-80/T-33 family was subsequently developed by Lockheed leading to the late 1950s to 1970s T2V-1/T-1A SeaStar; the two TF-80C prototypes were modified as prototypes for an all-weather two-seater fighter variant which became the F-94 Starfire. A total of 6,557 T-33s were produced, 5,691 of them by Lockheed, as well as 210 by Kawasaki and 656 by Canadair; the two-place T-33 proved suitable as an advanced trainer, it has been used for such tasks as drone director and target towing. The U. S. Air Force began phasing the T-33 out of front line pilot training duties in the Air Training Command in the early 1960s as the Cessna T-37 Tweet and Northrop T-38 Talon aircraft began replacing it for the Undergraduate Pilot Training program.
The T-33 was used to train cadets from the Air Force Academy at Peterson Field. The T-37 replaced the T-33 for Academy training in 1975; the final T-33 used in advanced training was replaced 8 February 1967 at Alabama. Similar replacement occurred in the U. S. Navy with the TV-1 as more advanced aircraft such as the North American T-2 Buckeye and Douglas TA-4 Skyhawk II came on line. USAF and USN versions of the T-33 soldiered on into the 1970s and 1980s with USAF and USN as utility aircraft and proficiency trainers, with some of the former USN aircraft being expended as full scale aerial targets for air-to-air missile tests from naval aircraft and surface-to-air missile tests from naval vessels. Several T-33s were assigned to USAF McDonnell F-101 Voodoo, Convair F-102 Delta Dagger, Convair F-106 Delta Dart units, to include equipped Air National Guard units, of the Aerospace Defense Command as proficiency trainers and practice "bogey" aircraft. Others went to Tactical Air Command and TAC-gained Air National Guard F-106 and McDonnell-Douglas F-4 Phantom II units in a similar role until they were retired, with the last being an NT-33 variant retired in April 1997.
Some T-33s retained two machine guns for gunnery training, in some countries, the T-33 was used in combat: the Cuban Air Force used them during the Bay of Pigs Invasion, scoring several kills. The RT-33A version, reconnaissance aircraft produced for use by foreign countries, had a camera installed in the nose and additional equipment in the rear cockpit. T-33s continued to fly as currency trainers, drone towing and tactical simulation training, "hack" aircraft, electronic countermeasures, warfare training and test platforms right into the 1980s; the T-33 has served with over 30 nations, continues to operate as a trainer in smaller air forces. Canadair built 656 T-33s on licence for service in the RCAF—Canadian Forces as the CT-133 Silver Star while Kawasaki manufactured 210 in Japan. Other operators included Brazil and Thailand which used the T-33 extensively. In the 1980s, an attempt was made to modify and modernize the T-33 as the Boeing Skyfox, but a lack of orders led to the project's cancellation.
About 70% of the T-33's airframe was retained in the Skyfox, but it was powered by two Garrett AiResearch TFE731-3A turbofan engines. In the late 1990s, 18 T-33 Mk-III and T-33 SF-SC from the Bolivian Air Force went to Canada to be modernized at Kelowna Flightcraft. New avionics were installed, detailed inspection and renewal of the fuselage and wings were performed. Most of the aircraft returned in early 2001 and remained operational until the type was retired on 31 July 2017. A limited number of T-33s have been owned with two used by Boeing as chase aircraft. In 2010, one T-33 owned by Boeing was used as a chase aircraft during the maiden flight of the Boeing 787; the maiden flight of the Boeing 737 MAX-7, March 16, 2018 featured a T-33 chase plane. Actor and pilot Michael Dorn owned a T-33. TP-80C Original United States military designation for the Lockheed Model 580 two-seat trainer for the United States Army Air Forces. Designation changed to TF-80C on 11 June 1948 following establishment of the United States Air Force as a separate military service in 1947, to T-33A on 5 May 1949.
T-33A Two-seat jet trainer aircraft for the United States Air Force and delivery to foreign air forces under the Military Assistance Program, 5871 inclu
A census is the procedure of systematically acquiring and recording information about the members of a given population. The term is used in connection with national population and housing censuses; the United Nations defines the essential features of population and housing censuses as "individual enumeration, universality within a defined territory and defined periodicity", recommends that population censuses be taken at least every 10 years. United Nations recommendations cover census topics to be collected, official definitions and other useful information to co-ordinate international practice; the word is of Latin origin: during the Roman Republic, the census was a list that kept track of all adult males fit for military service. The modern census is essential to international comparisons of any kind of statistics, censuses collect data on many attributes of a population, not just how many people there are. Censuses began as the only method of collecting national demographic data, are now part of a larger system of different surveys.
Although population estimates remain an important function of a census, including the geographic distribution of the population, statistics can be produced about combinations of attributes e.g. education by age and sex in different regions. Current administrative data systems allow for other approaches to enumeration with the same level of detail but raise concerns about privacy and the possibility of biasing estimates. A census can be contrasted with sampling in which information is obtained only from a subset of a population. Modern census data are used for research, business marketing, planning, as a baseline for designing sample surveys by providing a sampling frame such as an address register. Census counts are necessary to adjust samples to be representative of a population by weighting them as is common in opinion polling. Stratification requires knowledge of the relative sizes of different population strata which can be derived from census enumerations. In some countries, the census provides the official counts used to apportion the number of elected representatives to regions.
In many cases, a chosen random sample can provide more accurate information than attempts to get a population census. A census is construed as the opposite of a sample as its intent is to count everyone in a population rather than a fraction. However, population censuses rely on a sampling frame to count the population; this is the only way to be sure that everyone has been included as otherwise those not responding would not be followed up on and individuals could be missed. The fundamental premise of a census is that the population is not known and a new estimate is to be made by the analysis of primary data; the use of a sampling frame is counterintuitive as it suggests that the population size is known. However, a census is used to collect attribute data on the individuals in the nation; this process of sampling marks the difference between historical census, a house to house process or the product of an imperial decree, the modern statistical project. The sampling frame used by census is always an address register.
Thus it is not known how many people there are in each household. Depending on the mode of enumeration, a form is sent to the householder, an enumerator calls, or administrative records for the dwelling are accessed; as a preliminary to the dispatch of forms, census workers will check any address problems on the ground. While it may seem straightforward to use the postal service file for this purpose, this can be out of date and some dwellings may contain a number of independent households. A particular problem is what are termed'communal establishments' which category includes student residences, religious orders, homes for the elderly, people in prisons etc; as these are not enumerated by a single householder, they are treated differently and visited by special teams of census workers to ensure they are classified appropriately. Individuals are counted within households and information is collected about the household structure and the housing. For this reason international documents refer to censuses of housing.
The census response is made by a household, indicating details of individuals resident there. An important aspect of census enumerations is determining which individuals can be counted from which cannot be counted. Broadly, three definitions can be used: de facto residence; this is important to consider individuals who have temporary addresses. Every person should be identified uniquely as resident in one place but where they happen to be on Census Day, their de facto residence, may not be the best place to count them. Where an individual uses services may be more useful and this is at their usual, or de jure, residence. An individual may be represented at a permanent address a family home for students or long term migrants, it is necessary to have a precise definition of residence to decide whether visitors to a country should be included in the population count. This is becoming more important as students travel abroad for education for a period of several years. Other groups causing problems of enumeration are new born babies, people away on holiday, people moving home around census day, people without a fixed address.
People having second homes because of working in another part of the country or retaining a holiday cottage are dif
Marriage called matrimony or wedlock, is a or ritually recognised union between spouses that establishes rights and obligations between those spouses, as well as between them and any resulting biological or adopted children and affinity. The definition of marriage varies around the world not only between cultures and between religions, but throughout the history of any given culture and religion, evolving to both expand and constrict in who and what is encompassed, but it is principally an institution in which interpersonal relationships sexual, are acknowledged or sanctioned. In some cultures, marriage is recommended or considered to be compulsory before pursuing any sexual activity; when defined broadly, marriage is considered a cultural universal. A marriage ceremony is known as a wedding. Individuals may marry for several reasons, including legal, libidinal, financial and religious purposes. Whom they marry may be influenced by gender determined rules of incest, prescriptive marriage rules, parental choice and individual desire.
In some areas of the world, arranged marriage, child marriage and sometimes forced marriage, may be practiced as a cultural tradition. Conversely, such practices may be outlawed and penalized in parts of the world out of concerns of the infringement of women's rights, or the infringement of children's rights, because of international law. Around the world in developed democracies, there has been a general trend towards ensuring equal rights within marriage for women and recognizing the marriages of interfaith and same-sex couples; these trends coincide with the broader human rights movement. Marriage can be recognized by a state, an organization, a religious authority, a tribal group, a local community, or peers, it is viewed as a contract. When a marriage is performed and carried out by a government institution in accordance with the marriage laws of the jurisdiction, without religious content, it is a civil marriage. Civil marriage recognizes and creates the rights and obligations intrinsic to matrimony before the state.
When a marriage is performed with religious content under the auspices of a religious institution it is a religious marriage. Religious marriage recognizes and creates the rights and obligations intrinsic to matrimony before that religion. Religious marriage is known variously as sacramental marriage in Catholicism, nikah in Islam, nissuin in Judaism, various other names in other faith traditions, each with their own constraints as to what constitutes, who can enter into, a valid religious marriage; some countries do not recognize locally performed religious marriage on its own, require a separate civil marriage for official purposes. Conversely, civil marriage does not exist in some countries governed by a religious legal system, such as Saudi Arabia, where marriages contracted abroad might not be recognized if they were contracted contrary to Saudi interpretations of Islamic religious law. In countries governed by a mixed secular-religious legal system, such as in Lebanon and Israel, locally performed civil marriage does not exist within the country, preventing interfaith and various other marriages contradicting religious laws from being entered into in the country, civil marriages performed abroad are recognized by the state if they conflict with religious laws.
The act of marriage creates normative or legal obligations between the individuals involved, any offspring they may produce or adopt. In terms of legal recognition, most sovereign states and other jurisdictions limit marriage to opposite-sex couples and a diminishing number of these permit polygyny, child marriages, forced marriages. In modern times, a growing number of countries developed democracies, have lifted bans on and have established legal recognition for the marriages of interfaith and same-sex couples; some cultures allow the dissolution of marriage through annulment. In some areas, child marriages and polygamy may occur in spite of national laws against the practice. Since the late twentieth century, major social changes in Western countries have led to changes in the demographics of marriage, with the age of first marriage increasing, fewer people marrying, more couples choosing to cohabit rather than marry. For example, the number of marriages in Europe decreased by 30% from 1975 to 2005.
In most cultures, married women had few rights of their own, being considered, along with the family's children, the property of the husband. In Europe, the United States, other places in the developed world, beginning in the late 19th century and lasting through the 21st century, marriage has undergone gradual legal changes, aimed at improving the rights of the wife; these changes included giving wives legal identities of their own, abolishing the right of husbands to physically discipline their wives, giving wives property rights, liberalizing divorce laws, providing wives with reproductive rights of their own, requiring a wife's consent when sexual relations occur. These changes have occurred in Western countries. In the 21st century, there continue to be controversies regarding the legal status of married women, legal acceptance of or leniency towards violence within marriage, traditional marriage customs such as dowry and bride price, for
McCranie's Turpentine Still
McCranie's Turpentine Still is a historic site in Willacoochee, Georgia. It was added to the National Register of Historic Places on June 28, 1976, it is located west of Willacoochee on U. S. 82. The McCranie family continued for generations; this turpentine still was built based on designs and methods from earlier eras. It was operated by three McCranie brothers, it ceased operation in 1942. The replacement of the fire distillation process by steam distillation and the labor shortage caused by World War II contributed to its closure; the still remains intact. National Register of Historic Places listings in Atkinson County, Georgia Naval stores industry "Stills, Murals, & Mills", by Lynne Taylor, Georgia Backroads, Spring 2008, pp. 33-35. Media related to McCranie's Turpentine Still at Wikimedia Commons
A ZIP Code is a postal code used by the United States Postal Service in a system it introduced in 1963. The term ZIP is an acronym for Zone Improvement Plan; the basic format consists of five digits. An extended ZIP+4 code was introduced in 1983 which includes the five digits of the ZIP Code, followed by a hyphen and four additional digits that reference a more specific location; the term ZIP Code was registered as a servicemark by the U. S. Postal Service, but its registration has since expired; the early history and context of postal codes began with postal district/zone numbers. The United States Post Office Department implemented postal zones for numerous large cities in 1943. For example: The "16" was the number of the postal zone in the specific city. By the early 1960s, a more organized system was needed, non-mandatory five-digit ZIP Codes were introduced nationwide on July 1, 1963; the USPOD issued its Publication 59: Abbreviations for Use with ZIP Code on October 1, 1963, with the list of two-letter state abbreviations which are written with both letters capitalized.
An earlier list in June had proposed capitalized abbreviations ranging from two to five letters. According to Publication 59, the two-letter standard was "based on a maximum 23-position line, because this has been found to be the most universally acceptable line capacity basis for major addressing systems", which would be exceeded by a long city name combined with a multi-letter state abbreviation, such as "Sacramento, Calif." along with the ZIP Code. The abbreviations have remained unchanged, with the exception of Nebraska, changed from NB to NE in 1969 at the request of the Canadian postal administration, to avoid confusion with the Canadian province of New Brunswick. Robert Moon is considered the father of the ZIP Code; the post office only credits Moon with the first three digits of the ZIP Code, which describe the sectional center facility or "sec center." An SCF is a central mail processing facility with those three digits. The fourth and fifth digits, which give a more precise locale within the SCF, were proposed by Henry Bentley Hahn Sr.
The SCF sorts mail to all post offices with those first three digits in their ZIP Codes. The mail is sorted according to the final two digits of the ZIP Code and sent to the corresponding post offices in the early morning. Sectional centers do not deliver mail and are not open to the public, most of their employees work the night shift. Mail picked up at post offices is sent to their own SCF in the afternoon, where the mail is sorted overnight. In the case of large cities, the last two digits coincide with the older postal zone number thus: In 1967, these became mandatory for second- and third-class bulk mailers, the system was soon adopted generally; the United States Post Office used a cartoon character, which it called Mr. ZIP, to promote the use of the ZIP Code, he was depicted with a legend such as "USE ZIP CODE" in the selvage of panes of postage stamps or on the covers of booklet panes of stamps. In 1971 Elmira Star-Gazette reporter Dick Baumbach found out the White House was not using a ZIP Code on its envelopes.
Herb Klein, special assistant to President Nixon, responded by saying the next printing of envelopes would include the ZIP Code. In 1983, the U. S. Postal Service introduced an expanded ZIP Code system that it called ZIP+4 called "plus-four codes", "add-on codes", or "add-ons". A ZIP+4 Code uses the basic five-digit code plus four additional digits to identify a geographic segment within the five-digit delivery area, such as a city block, a group of apartments, an individual high-volume receiver of mail, a post office box, or any other unit that could use an extra identifier to aid in efficient mail sorting and delivery. However, initial attempts to promote universal use of the new format met with public resistance and today the plus-four code is not required. In general, mail is read by a multiline optical character reader that instantly determines the correct ZIP+4 Code from the address—along with the more specific delivery point—and sprays an Intelligent Mail barcode on the face of the mail piece that corresponds to 11 digits—nine for the ZIP+4 Code and two for the delivery point.
For Post Office Boxes, the general rule is. The add-on code is one of the following: the last four digits of the box number, zero plus the last three digits of the box number, or, if the box number consists of fewer than four digits, enough zeros are attached to the front of the box number to produce a four-digit number. However, there is no uniform rule, so the ZIP+4 Code must be looked up individually for each box; the ZIP Code is translated into an Intelligent Mail barcode, printed on the mailpiece to make it easier for automated machines to sort. A barcode can be printed by the sender, it is better to let the post office put one on. In general, the post office uses OCR technology, though in some cases a human might have to read and enter the address. Customers who send bulk mail can get a discount on postage if they have printed the barcode themselves and have presorted the mai