Pennsylvania the Commonwealth of Pennsylvania, is a state located in the northeastern and Mid-Atlantic regions of the United States. The Appalachian Mountains run through its middle; the Commonwealth is bordered by Delaware to the southeast, Maryland to the south, West Virginia to the southwest, Ohio to the west, Lake Erie and the Canadian province of Ontario to the northwest, New York to the north, New Jersey to the east. Pennsylvania is the 33rd-largest state by area, the 6th-most populous state according to the most recent official U. S. Census count in 2010, it is the 9th-most densely populated of the 50 states. Pennsylvania's two most populous cities are Philadelphia, Pittsburgh; the state capital and its 10th largest city is Harrisburg. Pennsylvania has 140 miles of waterfront along the Delaware Estuary; the state is one of the 13 original founding states of the United States. Part of Pennsylvania, together with the present State of Delaware, had earlier been organized as the Colony of New Sweden.
It was the second state to ratify the United States Constitution, on December 12, 1787. Independence Hall, where the United States Declaration of Independence and United States Constitution were drafted, is located in the state's largest city of Philadelphia. During the American Civil War, the Battle of Gettysburg was fought in the south central region of the state. Valley Forge near Philadelphia was General Washington's headquarters during the bitter winter of 1777–78. Pennsylvania is 170 miles north to south and 283 miles east to west. Of a total 46,055 square miles, 44,817 square miles are land, 490 square miles are inland waters, 749 square miles are waters in Lake Erie, it is the 33rd-largest state in the United States. Pennsylvania has 51 miles of coastline along Lake Erie and 57 miles of shoreline along the Delaware Estuary. Of the original Thirteen Colonies, Pennsylvania is the only state that does not border the Atlantic Ocean; the boundaries of the state are the Mason–Dixon line to the south, the Twelve-Mile Circle on the Pennsylvania-Delaware border, the Delaware River to the east, 80° 31' W to the west and the 42° N to the north, with the exception of a short segment on the western end, where a triangle extends north to Lake Erie.
Cities include Philadelphia, Reading and Lancaster in the southeast, Pittsburgh in the southwest, the tri-cities of Allentown and Easton in the central east. The northeast includes the former anthracite coal mining cities of Scranton, Wilkes-Barre and Hazleton. Erie is located in the northwest. State College serves the central region while Williamsport serves the commonwealth's north-central region as does Chambersburg the south-central region, with York and the state capital Harrisburg on the Susquehanna River in the east-central region of the Commonwealth and Altoona and Johnstown in the west-central region; the state has five geographical regions, namely the Allegheny Plateau and Valley, Atlantic Coastal Plain and the Erie Plain. New York Ontario Maryland Delaware West Virginia New Jersey Ohio Pennsylvania's diverse topography produces a variety of climates, though the entire state experiences cold winters and humid summers. Straddling two major zones, the majority of the state, with the exception of the southeastern corner, has a humid continental climate.
The southern portion of the state has a humid subtropical climate. The largest city, has some characteristics of the humid subtropical climate that covers much of Delaware and Maryland to the south. Summers are hot and humid. Moving toward the mountainous interior of the state, the winter climate becomes colder, the number of cloudy days increases, snowfall amounts are greater. Western areas of the state locations near Lake Erie, can receive over 100 inches of snowfall annually, the entire state receives plentiful precipitation throughout the year; the state may be subject to severe weather from spring through summer into fall. Tornadoes occur annually in the state, sometimes in large numbers, such as 30 recorded tornadoes in 2011; as of 1600, the tribes living in Pennsylvania were the Algonquian Lenape, the Iroquoian Susquehannock & Petun and the Siouan Monongahela Culture, who may have been the same as a little known tribe called the Calicua, or Cali. Other tribes who entered the region during the colonial era were the Trockwae, Saponi, Nanticoke, Conoy Piscataway, Iroquois Confederacy—possibly among others.
Other tribes, like the Erie, may have once held some land in Pennsylvania, but no longer did so by the year 1600. Both the Dutch and the English claimed both sides of the Delaware River as part of their colonial lands in America; the Dutch were the first to take possession. By June 3, 1631, the Dutch had begun settling the Delmarva Peninsula by establishing the Zwaanendael Colony on the site of present-day Lewes, Delaware. In 1638, Sweden established the New Sweden Colony, in the region of Fort Christina, on the site of present-day Wilmington, Delaware. New Sweden claimed and, for the most part, controlled the lower Delaware River region (parts of present-day Delaware, New Jersey, Pe
National Historic Landmark
A National Historic Landmark is a building, object, site, or structure, recognized by the United States government for its outstanding historical significance. Of over 90,000 places listed on the country's National Register of Historic Places, only some 2,500 are recognized as National Historic Landmarks. A National Historic Landmark District may include contributing properties that are buildings, sites or objects, it may include non-contributing properties. Contributing properties may or may not be separately listed. Prior to 1935, efforts to preserve cultural heritage of national importance were made by piecemeal efforts of the United States Congress. In 1935, Congress passed the Historic Sites Act, which authorized the Interior Secretary authority to formally record and organize historic properties, to designate properties as having "national historical significance", gave the National Park Service authority to administer significant federally owned properties. Over the following decades, surveys such as the Historic American Buildings Survey amassed information about culturally and architecturally significant properties in a program known as the Historic Sites Survey.
Most of the designations made under this legislation became National Historic Sites, although the first designation, made December 20, 1935, was for a National Memorial, the Gateway Arch National Park in St. Louis, Missouri; the first National Historic Site designation was made for the Salem Maritime National Historic Site on March 17, 1938. In 1960, the National Park Service took on the administration of the survey data gathered under this legislation, the National Historic Landmark program began to take more formal shape; when the National Register of Historic Places was established in 1966, the National Historic Landmark program was encompassed within it, rules and procedures for inclusion and designation were formalized. Because listings triggered local preservation laws, legislation in 1980 amended the listing procedures to require owner agreement to the designations. On October 9, 1960, 92 properties were announced as designated NHLs by Secretary of the Interior Fred A. Seaton; the first of these was a political nomination: the Sergeant Floyd Monument in Sioux City, Iowa was designated on June 30 of that year, but for various reasons, the public announcement of the first several NHLs was delayed.
NHLs are designated by the United States Secretary of the Interior because they are: Sites where events of national historical significance occurred. More than 2,500 NHLs have been designated. Most, but not all, are in the United States. There are the District of Columbia. Three states account for nearly 25 percent of the nation's NHLs. Three cities within these states all separately have more NHLs than 40 of the 50 states. In fact, New York City alone has more NHLs than all but five states: Virginia, Pennsylvania and New York. There are 74 NHLs in the District of Columbia; some NHLs are in U. S. commonwealths and territories, associated states, foreign states. There are 15 in Puerto Rico, the Virgin Islands, other U. S. territories. S.-associated states such as Micronesia. Over 100 ships or shipwrecks have been designated as NHLs. About half of the National Historic Landmarks are owned; the National Historic Landmarks Program relies on suggestions for new designations from the National Park Service, which assists in maintaining the landmarks.
A friends' group of owners and managers, the National Historic Landmark Stewards Association, works to preserve and promote National Historic Landmarks. If not listed on the National Register of Historic Places, an NHL is automatically added to the Register upon designation. About three percent of Register listings are NHLs. American Water Landmark List of U. S. National Historic Landmarks by state List of churches that are National Historic Landmarks in the United States Listed building, a similar designation in the UK National Historic Sites and Persons, similar designations in Canada National Natural Landmark United States Memorials United States National Register of Historic Places listings Official National Historic Landmarks Program website A History of the NHL Program List of National Historic Landmarks National Historic Landmarks: Archaeological Properties Historical Landmarks - United States Lighthouses
Bristol is a city and county in South West England with a population of 459,300. The wider district has the 10th-largest population in England; the urban area population of 724,000 is the 8th-largest in the UK. The city borders North Somerset and South Gloucestershire, with the cities of Bath and Gloucester to the south-east and north-east, respectively. South Wales lies across the Severn estuary. Iron Age hill forts and Roman villas were built near the confluence of the rivers Frome and Avon, around the beginning of the 11th century the settlement was known as Brycgstow. Bristol received a royal charter in 1155 and was divided between Gloucestershire and Somerset until 1373, when it became a county of itself. From the 13th to the 18th century, Bristol was among the top three English cities after London in tax receipts. Bristol was surpassed by the rapid rise of Birmingham and Liverpool in the Industrial Revolution. Bristol was a starting place for early voyages of exploration to the New World.
On a ship out of Bristol in 1497 John Cabot, a Venetian, became the first European since the Vikings to land on mainland North America. In 1499 William Weston, a Bristol merchant, was the first Englishman to lead an exploration to North America. At the height of the Bristol slave trade, from 1700 to 1807, more than 2,000 slave ships carried an estimated 500,000 people from Africa to slavery in the Americas; the Port of Bristol has since moved from Bristol Harbour in the city centre to the Severn Estuary at Avonmouth and Royal Portbury Dock. Bristol's modern economy is built on the creative media and aerospace industries, the city-centre docks have been redeveloped as centres of heritage and culture; the city has the largest circulating community currency in the UK—the Bristol pound, pegged to the Pound sterling. The city has two universities, the University of Bristol and the University of the West of England, a variety of artistic and sporting organisations and venues including the Royal West of England Academy, the Arnolfini, Spike Island, Ashton Gate and the Memorial Stadium.
It is connected to London and other major UK cities by road and rail, to the world by sea and air: road, by the M5 and M4. One of the UK's most popular tourist destinations, Bristol was selected in 2009 as one of the world's top ten cities by international travel publishers Dorling Kindersley in their Eyewitness series of travel guides; the Sunday Times named it as the best city in Britain in which to live in 2014 and 2017, Bristol won the EU's European Green Capital Award in 2015. The most ancient recorded name for Bristol is the archaic Welsh Caer Odor, consistent with modern understanding that early Bristol developed between the River Frome and Avon Gorge, it is most stated that the Saxon name Bricstow was a simple calque of the existing Celtic name, with Bric a literal translation of Odor, the common Saxon suffix Stow replacing Caer. Alternative etymologies are supported by numerous orthographic variations in medieval documents, with Samuel Seyer enumerating 47 alternative forms; the Old English form Brycgstow is used to derive the meaning place at the bridge.
Utilizing another form, Rev. Dr. Shaw derived the name from the Celtic words bras, or braos and tuile; the poet Thomas Chatterton popularised a derivation from Brictricstow linking the town to Brictric, a leading landholder in the area. It appears that the form Bricstow prevailed until 1204, the Bristolian'L' is what changed the name to Bristol. Archaeological finds, including flint tools believed to be between 300,000 and 126,000 years old made with the Levallois technique, indicate the presence of Neanderthals in the Shirehampton and St Annes areas of Bristol during the Middle Palaeolithic. Iron Age hill forts near the city are at Leigh Woods and Clifton Down, on the side of the Avon Gorge, on Kings Weston Hill near Henbury. A Roman settlement, existed at what is now Sea Mills. Isolated Roman villas and small forts and settlements were scattered throughout the area. Bristol was founded by 1000. By 1067 Brycgstow was a well-fortified burh, that year the townsmen beat off a raiding party from Ireland led by three of Harold Godwinson's sons.
Under Norman rule, the town had one of the strongest castles in southern England. Bristol was the place of exile for Diarmait Mac Murchada, the Irish king of Leinster, after being overthrown; the Bristol merchants subsequently played a prominent role in funding Richard Strongbow de Clare and the Norman invasion of Ireland. The port developed in the 11th century around the confluence of the Rivers Frome and Avon, adjacent to Bristol Bridge just outside the town walls. By the 12th century Bristol was an important port, handling much of England's trade with Ireland, including slaves. There was an important Jewish community in Bristol from the late 12th century through to the late 13th century when all Jews were expelled from England; the stone bridge built in 1247 was replaced by the current bridge during the 1760s. The town incorporated neighbouring suburbs and became a county in 1373, the first town in England to be given this status. During this period, Bristol became manufacturing centre. By the 14th centur
Marcus Tullius Cicero was a Roman statesman, orator and philosopher, who served as consul in the year 63 BC. He came from a wealthy municipal family of the Roman equestrian order, is considered one of Rome's greatest orators and prose stylists, his influence on the Latin language was so immense that the subsequent history of prose, not only in Latin but in European languages up to the 19th century, was said to be either a reaction against or a return to his style. Cicero introduced the Romans to the chief schools of Greek philosophy and created a Latin philosophical vocabulary distinguishing himself as a translator and philosopher. Though he was an accomplished orator and successful lawyer, Cicero believed his political career was his most important achievement, it was during his consulship that the second Catilinarian conspiracy attempted to overthrow the government through an attack on the city by outside forces, Cicero suppressed the revolt by summarily and controversially executing five conspirators.
During the chaotic latter half of the 1st century BC marked by civil wars and the dictatorship of Gaius Julius Caesar, Cicero championed a return to the traditional republican government. Following Julius Caesar's death, Cicero became an enemy of Mark Antony in the ensuing power struggle, attacking him in a series of speeches, he was proscribed as an enemy of the state by the Second Triumvirate and executed by soldiers operating on their behalf in 43 BC after having been intercepted during an attempted flight from the Italian peninsula. His severed hands and head were as a final revenge of Mark Antony, displayed on The Rostra. Petrarch's rediscovery of Cicero's letters is credited for initiating the 14th-century Renaissance in public affairs and classical Roman culture. According to Polish historian Tadeusz Zieliński, "the Renaissance was above all things a revival of Cicero, only after him and through him of the rest of Classical antiquity." The peak of Cicero's authority and prestige came during the 18th-century Enlightenment, his impact on leading Enlightenment thinkers and political theorists such as John Locke, David Hume and Edmund Burke was substantial.
His works rank among the most influential in European culture, today still constitute one of the most important bodies of primary material for the writing and revision of Roman history the last days of the Roman Republic. Cicero was born in 106 BC in a hill town 100 kilometers southeast of Rome, he belonged to the tribus Cornelia. His father possessed good connections in Rome. However, being a semi-invalid, he studied extensively to compensate. Although little is known about Cicero's mother, Helvia, it was common for the wives of important Roman citizens to be responsible for the management of the household. Cicero's brother Quintus wrote in a letter. Cicero's cognomen, or personal surname, comes from the Latin for cicer. Plutarch explains that the name was given to one of Cicero's ancestors who had a cleft in the tip of his nose resembling a chickpea. However, it is more that Cicero's ancestors prospered through the cultivation and sale of chickpeas. Romans chose down-to-earth personal surnames.
The famous family names of Fabius and Piso come from the Latin names of beans and peas, respectively. Plutarch writes that Cicero was urged to change this deprecatory name when he entered politics, but refused, saying that he would make Cicero more glorious than Scaurus and Catulus. During this period in Roman history, "cultured" meant being able to speak both Greek. Cicero was therefore educated in the teachings of the ancient Greek philosophers and historians. Cicero used his knowledge of Greek to translate many of the theoretical concepts of Greek philosophy into Latin, thus translating Greek philosophical works for a larger audience, it was his broad education that tied him to the traditional Roman elite. Cicero's interest in philosophy figured in his career and led to him providing a comprehensive account of Greek philosophy for a Roman audience, including creating a philosophical vocabulary in Latin. In 87 BC, Philo of Larissa, the head of the Academy, founded by Plato in Athens about 300 years earlier, arrived in Rome.
Cicero, "inspired by an extraordinary zeal for philosophy", sat enthusiastically at his feet and absorbed Plato's philosophy. Cicero said of Plato's Dialogues. According to Plutarch, Cicero was an talented student, whose learning attracted attention from all over Rome, affording him the opportunity to study Roman law under Quintus Mucius Scaevola. Cicero's fellow students were Gaius Marius Minor, Servius Sulpicius Rufus, Titus Pomponius; the latter two became Cicero's friends for life, Pomponius would become, in Cicero's own words, "as a second brother", with both maintaining a lifelong correspondence. In 79 BC, Cicero left for Asia Minor and Rhodes; this was to avoid the potential wrath of Sulla, as Plutarch claims, though Cicero himself says it was to hone his skills and improve his p
Benjamin Franklin was an American polymath and one of the Founding Fathers of the United States. Franklin was a leading author, political theorist, freemason, scientist, humorist, civic activist and diplomat; as a scientist, he was a major figure in the American Enlightenment and the history of physics for his discoveries and theories regarding electricity. As an inventor, he is known for the lightning rod and the Franklin stove, among other inventions, he founded many civic organizations, including the Library Company, Philadelphia's first fire department and the University of Pennsylvania. Franklin earned the title of "The First American" for his early and indefatigable campaigning for colonial unity as an author and spokesman in London for several colonies; as the first United States Ambassador to France, he exemplified the emerging American nation. Franklin was foundational in defining the American ethos as a marriage of the practical values of thrift, hard work, community spirit, self-governing institutions, opposition to authoritarianism both political and religious, with the scientific and tolerant values of the Enlightenment.
In the words of historian Henry Steele Commager, "In a Franklin could be merged the virtues of Puritanism without its defects, the illumination of the Enlightenment without its heat." To Walter Isaacson, this makes Franklin "the most accomplished American of his age and the most influential in inventing the type of society America would become."Franklin became a successful newspaper editor and printer in Philadelphia, the leading city in the colonies, publishing the Pennsylvania Gazette at the age of 23. He became wealthy publishing this and Poor Richard's Almanack, which he authored under the pseudonym "Richard Saunders". After 1767, he was associated with the Pennsylvania Chronicle, a newspaper, known for its revolutionary sentiments and criticisms of British policies, he pioneered and was first president of Academy and College of Philadelphia which opened in 1751 and became the University of Pennsylvania. He organized and was the first secretary of the American Philosophical Society and was elected president in 1769.
Franklin became a national hero in America as an agent for several colonies when he spearheaded an effort in London to have the Parliament of Great Britain repeal the unpopular Stamp Act. An accomplished diplomat, he was admired among the French as American minister to Paris and was a major figure in the development of positive Franco-American relations, his efforts proved vital for the American Revolution in securing shipments of crucial munitions from France. He was promoted to deputy postmaster-general for the British colonies in 1753, having been Philadelphia postmaster for many years, this enabled him to set up the first national communications network. During the revolution, he became the first United States Postmaster General, he was active in community affairs and colonial and state politics, as well as national and international affairs. From 1785 to 1788, he served as governor of Pennsylvania, he owned and dealt in slaves but, by the 1750s, he argued against slavery from an economic perspective and became one of the most prominent abolitionists.
His colorful life and legacy of scientific and political achievement, his status as one of America's most influential Founding Fathers, have seen Franklin honored more than two centuries after his death on coinage and the $100 bill and the names of many towns, educational institutions, corporations, as well as countless cultural references. Benjamin Franklin's father, Josiah Franklin, was a soaper and candlemaker. Josiah was born at Ecton, England on December 23, 1657, the son of blacksmith and farmer Thomas Franklin, Jane White. Benjamin's father and all four of his grandparents were born in England. Josiah had seventeen children with his two wives, he married his first wife, Anne Child, in about 1677 in Ecton and immigrated with her to Boston in 1683. Following her death, Josiah was married to Abiah Folger on July 9, 1689 in the Old South Meeting House by Samuel Willard. Benjamin, their eighth child, was Josiah Franklin's fifteenth tenth and last son. Abiah Folger was born in Nantucket, Massachusetts, on August 15, 1667, to Peter Folger, a miller and schoolteacher, his wife, Mary Morrell Folger, a former indentured servant.
She came from a Puritan family, among the first Pilgrims to flee to Massachusetts for religious freedom, when King Charles I of England began persecuting Puritans. They sailed for Boston in 1635, her father was "the sort of rebel destined to transform colonial America." As clerk of the court, he was jailed for disobeying the local magistrate in defense of middle-class shopkeepers and artisans in conflict with wealthy landowners. Ben Franklin followed in his grandfather's footsteps in his battles against the wealthy Penn family that owned the Pennsylvania Colony. Benjamin Franklin was born on Milk Street, in Boston, Massachusetts, on January 17, 1706, baptized at Old South Meeting House, he was one of seventeen children born to Josiah Franklin, one of ten born by Josiah's second wife, Abiah Folger. Among Benjamin's siblings were his older brother James and his younger sister Jane. Josiah wanted Ben to attend school with the clergy, but only had enough money to send him to school for two years, he did not graduate.
Although "his parents talked of the church as a career" for Franklin, his schooling e
The Walking Purchase was an alleged 1737 agreement between the Penn family, the original proprietors of the Province of Pennsylvania in the colonial era, the Lenape native Indians. By it the Penn family and proprietors claimed an area of 1,200,000 acres along the northern reaches of the Delaware River at the northeastern boundary between the Province of Pennsylvania and the West New Jersey area to the east of the Province of New Jersey and forced the Lenape to vacate it; the Lenape appeal to the Iroquois Indian tribe further north for aid on the issue was refused. In the legal suit / court case of Delaware Nation v. Pennsylvania, the Delaware nation and its descendents in the 21st century claimed 314 acres of land included in the original so-called "purchase" in 1737, but the U. S. District Court granted the Commonwealth's motion to dismiss, it ruled that the case was nonjusticiable, although it acknowledged that Indian title appeared to have been extinguished by fraud. This ruling held through several appealed actions made through several levels of the United States courts of appeals.
The Supreme Court of the United States refused to hear the case which had the effect of upholding the lower appeals courts decision. Founder of the Colony William Penn in 1681, enjoyed a reputation for fair-dealing with the Lenape. However, his heirs, John Penn and Thomas Penn, abandoned many of the elder father Penn's moderate practices. In 1736, they claimed a deed from 1686 by which the Lenape promised to sell a tract beginning at the junction of the upper Delaware River and the tributary Lehigh River and extending as far west as a man could walk in a day and a half to become known as the "Walking Purchase" or the Walking Treaty of 1737; this document may have been an unsigned, unratified treaty, or an outright forgery. The Penns' agents began selling land in the Lehigh Valley in the disputed area along the Lehigh River to colonists while the Lenape still inhabited the area. To allay the Lenapes' misgivings and suspicions, Penn Land Office Agent and provincial secretary, James Logan, produced a map incorrectly misrepresenting the farther Lehigh River as the closer Tohickon Creek, including a dotted line showing a reasonable path that the "walkers" would take.
Satisfied that the land in question was not so terrible a price to honor the old deed, the Lenape signed. According to the popular account, Lenape leaders assumed that about 40 miles was the longest distance that could be covered under these conditions. Provincial Secretary Logan hired the three fastest runners in the colony, Edward Marshall, Solomon Jennings and James Yeates, to run on a prepared trail, they were supervised during the "walk" by the Sheriff of Bucks County Timothy Smith. The walk occurred on September 19, 1737. At the end of the walk, Sheriff Smith drew a perpendicular line back toward the northeast, claimed all the land east of these two lines ending at the Delaware River; this resulted in an area of 1,200,932 acres - 1.2 million acres equivalent to the size of Rhode Island, located in the modern seven counties of eastern Pennsylvania as: Pike, Carbon, Northampton and Bucks. The Delaware leaders appealed for assistance to the Iroquois confederacy tribe to the north, who claimed hegemony over the Delaware.
The Iroquois leaders decided that it was not in their best interest politically to intervene on behalf of their southern neighbors the Delaware. Pennsylvania provincial secretary James Logan had made a deal with the Iroquois to support the colonial side; as a result, the Lenape had to soon vacate the Walking Purchase lands. Chief Lappawinsoe and other Lenape leaders continued to protest the arrangement, as the Lenape were forced into the Shamokin and Wyoming River valleys crowded with other displaced tribes; some Lenape moved further west into the Ohio Country and the southern and western claims of the Kingdom of France in their territory of New France, west of the French Fort Duquesne at the "Forks of the Ohio". Because of the Walking Purchase, the Lenape grew to distrust the Pennsylvania government, its once good reputation with the various tribes begun by the wise peaceful William Penn was lost forever. In 2004, the Delaware Nation filed suit against Pennsylvania in the United States District Court for the Eastern District of Pennsylvania, seeking 314 acres included in the 1737 Walking Purchase and patented in 1741, known as "Tatamy's Place."
The court granted the Commonwealth's motion to dismiss. According to the District Court: Penn's government and practices differed from the Puritan-led governments of the other American colonies; the most striking difference was Penn's ability to cultivate a positive relationship based on mutual respect with the Native Americans inhabiting the province. While the Puritans "stole from the Indians... Penn achieved peaceful relations with the Indians."The District Court recounted its understanding of the facts of the Walking Purchase: Penn's sons were less interested than their father in cultivating a friendship with the Lenni Lenape. Thomas Penn, in particular, i
Natural science is a branch of science concerned with the description and understanding of natural phenomena, based on empirical evidence from observation and experimentation. Mechanisms such as peer review and repeatability of findings are used to try to ensure the validity of scientific advances. Natural science can be divided into two main branches: physical science. Physical science is subdivided into branches, including physics, chemistry and earth science; these branches of natural science may be further divided into more specialized branches. In Western society's analytic tradition, the empirical sciences and natural sciences use tools from formal sciences, such as mathematics and logic, converting information about nature into measurements which can be explained as clear statements of the "laws of nature"; the social sciences use such methods, but rely more on qualitative research, so that they are sometimes called "soft science", whereas natural sciences, insofar as they emphasize quantifiable data produced and confirmed through the scientific method, are sometimes called "hard science".
Modern natural science succeeded more classical approaches to natural philosophy traced to ancient Greece. Galileo, Descartes and Newton debated the benefits of using approaches which were more mathematical and more experimental in a methodical way. Still, philosophical perspectives and presuppositions overlooked, remain necessary in natural science. Systematic data collection, including discovery science, succeeded natural history, which emerged in the 16th century by describing and classifying plants, minerals, so on. Today, "natural history" suggests observational descriptions aimed at popular audiences. Philosophers of science have suggested a number of criteria, including Karl Popper's controversial falsifiability criterion, to help them differentiate scientific endeavors from non-scientific ones. Validity and quality control, such as peer review and repeatability of findings, are amongst the most respected criteria in the present-day global scientific community; this field encompasses a set of disciplines.
The scale of study can range from sub-component biophysics up to complex ecologies. Biology is concerned with the characteristics and behaviors of organisms, as well as how species were formed and their interactions with each other and the environment; the biological fields of botany and medicine date back to early periods of civilization, while microbiology was introduced in the 17th century with the invention of the microscope. However, it was not until the 19th century. Once scientists discovered commonalities between all living things, it was decided they were best studied as a whole; some key developments in biology were the discovery of genetics. Modern biology is divided into subdisciplines by the type of organism and by the scale being studied. Molecular biology is the study of the fundamental chemistry of life, while cellular biology is the examination of the cell. At a higher level and physiology look at the internal structures, their functions, of an organism, while ecology looks at how various organisms interrelate.
Constituting the scientific study of matter at the atomic and molecular scale, chemistry deals with collections of atoms, such as gases, molecules and metals. The composition, statistical properties and reactions of these materials are studied. Chemistry involves understanding the properties and interactions of individual atoms and molecules for use in larger-scale applications. Most chemical processes can be studied directly in a laboratory, using a series of techniques for manipulating materials, as well as an understanding of the underlying processes. Chemistry is called "the central science" because of its role in connecting the other natural sciences. Early experiments in chemistry had their roots in the system of Alchemy, a set of beliefs combining mysticism with physical experiments; the science of chemistry began to develop with the work of Robert Boyle, the discoverer of gas, Antoine Lavoisier, who developed the theory of the Conservation of mass. The discovery of the chemical elements and atomic theory began to systematize this science, researchers developed a fundamental understanding of states of matter, chemical bonds and chemical reactions.
The success of this science led to a complementary chemical industry that now plays a significant role in the world economy. Physics embodies the study of the fundamental constituents of the universe, the forces and interactions they exert on one another, the results produced by these interactions. In general, physics is regarded as the fundamental science, because all other natural sciences use and obey the principles and laws set down by the field. Physics relies on mathematics as the logical framework for formulation and quantification of principles; the study of the principles of the universe has a long history and derives from direct observation and experimentation. The formulation of theories about the governing laws of the universe has been central to the study of physics from early on, with philosophy yielding to systematic, quantitative experimental testing and observation as the source of verification. Key historical developments in physics include Isaac Newton's theory of universal g