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Today, Warsaw has some of the best medical facilities in Poland and East-Central Europe. The city is home to the Children's Memorial Health Institute (CMHI), the highest-reference hospital in all of Poland, as well as an active research and education center. While the Maria Skłodowska-Curie Institute of Oncology it is one of the largest and most modern oncological institutions in Europe. The clinical section is located in a 10-floor building with 700 beds, 10 operating theatres, an intensive care unit, several diagnostic departments as well as an outpatient clinic. The infrastructure has developed a lot over the past years.
Thanks to numerous musical venues, including the Teatr Wielki, the Polish National Opera, the Chamber Opera, the National Philharmonic Hall and the National Theatre, as well as the Roma and Buffo music theatres and the Congress Hall in the Palace of Culture and Science, Warsaw hosts many events and festivals. Among the events worth particular attention are: the International Frédéric Chopin Piano Competition, the International Contemporary Music Festival Warsaw Autumn, the Jazz Jamboree, Warsaw Summer Jazz Days, the International Stanisław Moniuszko Vocal Competition, the Mozart Festival, and the Festival of Old Music.
Nearby, in Ogród Saski (the Saxon Garden), the Summer Theatre was in operation from 1870 to 1939, and in the inter-war period, the theatre complex also included Momus, Warsaw's first literary cabaret, and Leon Schiller's musical theatre Melodram. The Wojciech Bogusławski Theatre (1922–26), was the best example of "Polish monumental theatre". From the mid-1930s, the Great Theatre building housed the Upati Institute of Dramatic Arts – the first state-run academy of dramatic art, with an acting department and a stage directing department.
Several commemorative events take place every year. Gatherings of thousands of people on the banks of the Vistula on Midsummer’s Night for a festival called Wianki (Polish for Wreaths) have become a tradition and a yearly event in the programme of cultural events in Warsaw. The festival traces its roots to a peaceful pagan ritual where maidens would float their wreaths of herbs on the water to predict when they would be married, and to whom. By the 19th century this tradition had become a festive event, and it continues today. The city council organize concerts and other events. Each Midsummer’s Eve, apart from the official floating of wreaths, jumping over fires, looking for the fern flower, there are musical performances, dignitaries' speeches, fairs and fireworks by the river bank.
As interesting examples of expositions the most notable are: the world's first Museum of Posters boasting one of the largest collections of art posters in the world, Museum of Hunting and Riding and the Railway Museum. From among Warsaw's 60 museums, the most prestigious ones are National Museum with a collection of works whose origin ranges in time from antiquity till the present epoch as well as one of the best collections of paintings in the country including some paintings from Adolf Hitler's private collection, and Museum of the Polish Army whose set portrays the history of arms.
A fine tribute to the fall of Warsaw and history of Poland can be found in the Warsaw Uprising Museum and in the Katyń Museum which preserves the memory of the crime. The Warsaw Uprising Museum also operates a rare preserved and operating historic stereoscopic theatre, the Warsaw Fotoplastikon. The Museum of Independence preserves patriotic and political objects connected with Poland's struggles for independence. Dating back to 1936 Warsaw Historical Museum contains 60 rooms which host a permanent exhibition of the history of Warsaw from its origins until today.
The 17th century Royal Ujazdów Castle currently houses Centre for Contemporary Art, with some permanent and temporary exhibitions, concerts, shows and creative workshops. The Centre currently realizes about 500 projects a year. Zachęta National Gallery of Art, the oldest exhibition site in Warsaw, with a tradition stretching back to the mid-19th century organises exhibitions of modern art by Polish and international artists and promotes art in many other ways. Since 2011 Warsaw Gallery Weekend is held on last weekend of September.
Their local rivals, Polonia Warsaw, have significantly fewer supporters, yet they managed to win Ekstraklasa Championship in 2000. They also won the country’s championship in 1946, and won the cup twice as well. Polonia's home venue is located at Konwiktorska Street, a ten-minute walk north from the Old Town. Polonia was relegated from the country's top flight in 2013 because of their disastrous financial situation. They are now playing in the 4th league (5th tier in Poland) -the bottom professional league in the National – Polish Football Association (PZPN) structure.
The mermaid (syrenka) is Warsaw's symbol and can be found on statues throughout the city and on the city's coat of arms. This imagery has been in use since at least the mid-14th century. The oldest existing armed seal of Warsaw is from the year 1390, consisting of a round seal bordered with the Latin inscription Sigilium Civitatis Varsoviensis (Seal of the city of Warsaw). City records as far back as 1609 document the use of a crude form of a sea monster with a female upper body and holding a sword in its claws. In 1653 the poet Zygmunt Laukowski asks the question:
The origin of the legendary figure is not fully known. The best-known legend, by Artur Oppman, is that long ago two of Triton's daughters set out on a journey through the depths of the oceans and seas. One of them decided to stay on the coast of Denmark and can be seen sitting at the entrance to the port of Copenhagen. The second mermaid reached the mouth of the Vistula River and plunged into its waters. She stopped to rest on a sandy beach by the village of Warszowa, where fishermen came to admire her beauty and listen to her beautiful voice. A greedy merchant also heard her songs; he followed the fishermen and captured the mermaid.
One of the most famous people born in Warsaw was Maria Skłodowska-Curie, who achieved international recognition for her research on radioactivity and was the first female recipient of the Nobel Prize. Famous musicians include Władysław Szpilman and Frédéric Chopin. Though Chopin was born in the village of Żelazowa Wola, about 60 km (37 mi) from Warsaw, he moved to the city with his family when he was seven months old. Casimir Pulaski, a Polish general and hero of the American Revolutionary War, was born here in 1745.
Tamara de Lempicka was a famous artist born in Warsaw. She was born Maria Górska in Warsaw to wealthy parents and in 1916 married a Polish lawyer Tadeusz Łempicki. Better than anyone else she represented the Art Deco style in painting and art. Nathan Alterman, the Israeli poet, was born in Warsaw, as was Moshe Vilenski, the Israeli composer, lyricist, and pianist, who studied music at the Warsaw Conservatory. Warsaw was the beloved city of Isaac Bashevis Singer, which he described in many of his novels: Warsaw has just now been destroyed. No one will ever see the Warsaw I knew. Let me just write about it. Let this Warsaw not disappear forever, he commented.
The French and Indian War (1754–1763) was the North American theater of the worldwide Seven Years' War. The war was fought between the colonies of British America and New France, with both sides supported by military units from their parent countries of Great Britain and France, as well as Native American allies. At the start of the war, the French North American colonies had a population of roughly 60,000 European settlers, compared with 2 million in the British North American colonies. The outnumbered French particularly depended on the Indians. Long in conflict, the metropole nations declared war on each other in 1756, escalating the war from a regional affair into an intercontinental conflict.
The war was fought primarily along the frontiers between New France and the British colonies, from Virginia in the South to Nova Scotia in the North. It began with a dispute over control of the confluence of the Allegheny and Monongahela rivers, called the Forks of the Ohio, and the site of the French Fort Duquesne and present-day Pittsburgh, Pennsylvania. The dispute erupted into violence in the Battle of Jumonville Glen in May 1754, during which Virginia militiamen under the command of 22-year-old George Washington ambushed a French patrol.
In 1755, six colonial governors in North America met with General Edward Braddock, the newly arrived British Army commander, and planned a four-way attack on the French. None succeeded and the main effort by Braddock was a disaster; he was defeated in the Battle of the Monongahela on July 9, 1755 and died a few days later. British operations in 1755, 1756 and 1757 in the frontier areas of Pennsylvania and New York all failed, due to a combination of poor management, internal divisions, and effective Canadian scouts, French regular forces, and Indian warrior allies. In 1755, the British captured Fort Beauséjour on the border separating Nova Scotia from Acadia; soon afterward they ordered the expulsion of the Acadians. Orders for the deportation were given by William Shirley, Commander-in-Chief, North America, without direction from Great Britain. The Acadians, both those captured in arms and those who had sworn the loyalty oath to His Britannic Majesty, were expelled. Native Americans were likewise driven off their land to make way for settlers from New England.
After the disastrous 1757 British campaigns (resulting in a failed expedition against Louisbourg and the Siege of Fort William Henry, which was followed by Indian torture and massacres of British victims), the British government fell. William Pitt came to power and significantly increased British military resources in the colonies at a time when France was unwilling to risk large convoys to aid the limited forces it had in New France. France concentrated its forces against Prussia and its allies in the European theatre of the war. Between 1758 and 1760, the British military launched a campaign to capture the Colony of Canada. They succeeded in capturing territory in surrounding colonies and ultimately Quebec. Though the British were later defeated at Sainte Foy in Quebec, the French ceded Canada in accordance with the 1763 treaty.
The outcome was one of the most significant developments in a century of Anglo-French conflict. France ceded its territory east of the Mississippi to Great Britain. It ceded French Louisiana west of the Mississippi River (including New Orleans) to its ally Spain, in compensation for Spain's loss to Britain of Florida (Spain had ceded this to Britain in exchange for the return of Havana, Cuba). France's colonial presence north of the Caribbean was reduced to the islands of Saint Pierre and Miquelon, confirming Britain's position as the dominant colonial power in eastern North America.
The conflict is known by multiple names. In British America, wars were often named after the sitting British monarch, such as King William's War or Queen Anne's War. As there had already been a King George's War in the 1740s, British colonists named the second war in King George's reign after their opponents, and it became known as the French and Indian War. This traditional name continues as the standard in the United States, but it obscures the fact that Indians fought on both sides of the conflict, and that this was part of the Seven Years' War, a much larger conflict between France and Great Britain. American historians generally use the traditional name or sometimes the Seven Years' War. Other, less frequently used names for the war include the Fourth Intercolonial War and the Great War for the Empire.
In Europe, the North American theater of the Seven Years' War usually is not given a separate name. The entire international conflict is known as the Seven Years' War. "Seven Years" refers to events in Europe, from the official declaration of war in 1756 to the signing of the peace treaty in 1763. These dates do not correspond with the fighting on mainland North America, where the fighting between the two colonial powers was largely concluded in six years, from the Battle of Jumonville Glen in 1754 to the capture of Montreal in 1760.
The French population numbered about 75,000 and was heavily concentrated along the St. Lawrence River valley, with some also in Acadia (present-day New Brunswick and parts of Nova Scotia, including Île Royale (present-day Cape Breton Island)). Fewer lived in New Orleans, Biloxi, Mississippi, Mobile, Alabama and small settlements in the Illinois Country, hugging the east side of the Mississippi River and its tributaries. French fur traders and trappers traveled throughout the St. Lawrence and Mississippi watersheds, did business with local tribes, and often married Indian women. Traders married daughters of chiefs, creating high-ranking unions.
British settlers outnumbered the French 20 to 1 with a population of about 1.5 million ranged along the eastern coast of the continent, from Nova Scotia and Newfoundland in the north, to Georgia in the south. Many of the older colonies had land claims that extended arbitrarily far to the west, as the extent of the continent was unknown at the time their provincial charters were granted. While their population centers were along the coast, the settlements were growing into the interior. Nova Scotia, which had been captured from France in 1713, still had a significant French-speaking population. Britain also claimed Rupert's Land, where the Hudson's Bay Company traded for furs with local tribes.
In between the French and the British, large areas were dominated by native tribes. To the north, the Mi'kmaq and the Abenaki were engaged in Father Le Loutre's War and still held sway in parts of Nova Scotia, Acadia, and the eastern portions of the province of Canada, as well as much of present-day Maine. The Iroquois Confederation dominated much of present-day Upstate New York and the Ohio Country, although the latter also included Algonquian-speaking populations of Delaware and Shawnee, as well as Iroquoian-speaking Mingo. These tribes were formally under Iroquois rule, and were limited by them in authority to make agreements.
Further south the Southeast interior was dominated by Siouan-speaking Catawba, Muskogee-speaking Creek and Choctaw, and the Iroquoian-speaking Cherokee tribes. When war broke out, the French used their trading connections to recruit fighters from tribes in western portions of the Great Lakes region (an area not directly subject to the conflict between the French and British), including the Huron, Mississauga, Ojibwa, Winnebago, and Potawatomi. The British were supported in the war by the Iroquois Six Nations, and also by the Cherokee – until differences sparked the Anglo-Cherokee War in 1758. In 1758 the Pennsylvania government successfully negotiated the Treaty of Easton, in which a number of tribes in the Ohio Country promised neutrality in exchange for land concessions and other considerations. Most of the other northern tribes sided with the French, their primary trading partner and supplier of arms. The Creek and Cherokee were subject to diplomatic efforts by both the French and British to gain either their support or neutrality in the conflict. It was not uncommon for small bands to participate on the "other side" of the conflict from formally negotiated agreements, as most tribes were decentralized and bands made their own decisions about warfare.
At the start of the war, no French regular army troops were stationed in North America, and few British troops. New France was defended by about 3,000 troupes de la marine, companies of colonial regulars (some of whom had significant woodland combat experience). The colonial government recruited militia support when needed. Most British colonies mustered local militia companies, generally ill trained and available only for short periods, to deal with native threats, but did not have any standing forces.
Céloron's expedition force consisted of about 200 Troupes de la marine and 30 Indians. The expedition covered about 3,000 miles (4,800 km) between June and November 1749. It went up the St. Lawrence, continued along the northern shore of Lake Ontario, crossed the portage at Niagara, and followed the southern shore of Lake Erie. At the Chautauqua Portage (near present-day Barcelona, New York), the expedition moved inland to the Allegheny River, which it followed to the site of present-day Pittsburgh. There Céloron buried lead plates engraved with the French claim to the Ohio Country. Whenever he encountered British merchants or fur-traders, Céloron informed them of the French claims on the territory and told them to leave.
When Céloron's expedition arrived at Logstown, the Native Americans in the area informed Céloron that they owned the Ohio Country and that they would trade with the British regardless of the French. Céloron continued south until his expedition reached the confluence of the Ohio and the Miami rivers, which lay just south of the village of Pickawillany, the home of the Miami chief known as "Old Briton". Céloron threatened "Old Briton" with severe consequences if he continued to trade with the British. "Old Briton" ignored the warning. Disappointed, Céloron returned to Montreal in November 1749.
In his extensively detailed report, Céloron wrote, "All I can say is that the Natives of these localities are very badly disposed towards the French, and are entirely devoted to the English. I don't know in what way they could be brought back." Even before his return to Montreal, reports on the situation in the Ohio Country were making their way to London and Paris, each side proposing that action be taken. William Shirley, the expansionist governor of the Province of Massachusetts Bay, was particularly forceful, stating that British colonists would not be safe as long as the French were present. Conflicts between the colonies, accomplished through raiding parties that included Indian allies, had taken place for decades, leading to a brisk trade in European colonial captives from either side.
In 1749 the British government gave land to the Ohio Company of Virginia for the purpose of developing trade and settlements in the Ohio Country. The grant required that it settle 100 families in the territory, and construct a fort for their protection. But, as the territory was also claimed by Pennsylvania, both colonies began pushing for action to improve their respective claims. In 1750 Christopher Gist, acting on behalf of both Virginia and the company, explored the Ohio territory and opened negotiations with the Indian tribes at Logstown. He completed the 1752 Treaty of Logstown in which the local Indians, through their "Half-King" Tanacharison and an Iroquois representative, agreed to terms that included permission to build a "strong house" at the mouth of the Monongahela River (the site of present-day Pittsburgh, Pennsylvania). By the late 17th century, the Iroquois had pushed many tribes out of the Ohio Valley, and kept it as hunting ground by right of conquest.
The War of the Austrian Succession (whose North American theater is known as King George's War) formally ended in 1748 with the signing of the Treaty of Aix-la-Chapelle. The treaty was primarily focused on resolving issues in Europe. The issues of conflicting territorial claims between British and French colonies in North America were turned over to a commission to resolve, but it reached no decision. Frontiers from between Nova Scotia and Acadia in the north, to the Ohio Country in the south, were claimed by both sides. The disputes also extended into the Atlantic Ocean, where both powers wanted access to the rich fisheries of the Grand Banks off Newfoundland.
On March 17, 1752, the Governor-General of New France, Marquis de la Jonquière, died and was temporarily replaced by Charles le Moyne de Longueuil. His permanent replacement, the Marquis Duquesne, did not arrive in New France until 1752 to take over the post. The continuing British activity in the Ohio territories prompted Longueuil to dispatch another expedition to the area under the command of Charles Michel de Langlade, an officer in the Troupes de la Marine. Langlade was given 300 men, including French-Canadians and warriors of the Ottawa. His objective was to punish the Miami people of Pickawillany for not following Céloron's orders to cease trading with the British. On June 21, the French war party attacked the trading centre at Pickawillany, capturing three traders and killing 14 people of the Miami nation, including Old Briton. He was reportedly ritually cannibalized by some aboriginal members of the expedition.
In the spring of 1753, Paul Marin de la Malgue was given command of a 2,000-man force of Troupes de la Marine and Indians. His orders were to protect the King's land in the Ohio Valley from the British. Marin followed the route that Céloron had mapped out four years earlier, but where Céloron had limited the record of French claims to the burial of lead plates, Marin constructed and garrisoned forts. He first constructed Fort Presque Isle (near present-day Erie, Pennsylvania) on Lake Erie's south shore. He had a road built to the headwaters of LeBoeuf Creek. Marin constructed a second fort at Fort Le Boeuf (present-day Waterford, Pennsylvania), designed to guard the headwaters of LeBoeuf Creek. As he moved south, he drove off or captured British traders, alarming both the British and the Iroquois. Tanaghrisson, a chief of the Mingo, who were remnants of Iroquois and other tribes who had been driven west by colonial expansion. He intensely disliked the French (whom he accused of killing and eating his father). Traveling to Fort Le Boeuf, he threatened the French with military action, which Marin contemptuously dismissed.
The Iroquois sent runners to the manor of William Johnson in upstate New York. The British Superintendent for Indian Affairs in the New York region and beyond, Johnson was known to the Iroquois as Warraghiggey, meaning "He who does great things." He spoke their languages and had become a respected honorary member of the Iroquois Confederacy in the area. In 1746, Johnson was made a colonel of the Iroquois. Later he was commissioned as a colonel of the Western New York Militia. They met at Albany, New York with Governor Clinton and officials from some of the other American colonies. Mohawk Chief Hendrick, Speaker of their tribal council, insisted that the British abide by their obligations and block French expansion. When Clinton did not respond to his satisfaction, Chief Hendrick said that the "Covenant Chain", a long-standing friendly relationship between the Iroquois Confederacy and the British Crown, was broken.
Governor Robert Dinwiddie of Virginia was an investor in the Ohio Company, which stood to lose money if the French held their claim. To counter the French military presence in Ohio, in October 1753 Dinwiddie ordered the 21-year-old Major George Washington (whose brother was another Ohio Company investor) of the Virginia Regiment to warn the French to leave Virginia territory. Washington left with a small party, picking up along the way Jacob Van Braam as an interpreter; Christopher Gist, a company surveyor working in the area; and a few Mingo led by Tanaghrisson. On December 12, Washington and his men reached Fort Le Boeuf.
Jacques Legardeur de Saint-Pierre, who succeeded Marin as commander of the French forces after the latter died on October 29, invited Washington to dine with him. Over dinner, Washington presented Saint-Pierre with the letter from Dinwiddie demanding an immediate French withdrawal from the Ohio Country. Saint-Pierre said, "As to the Summons you send me to retire, I do not think myself obliged to obey it." He told Washington that France's claim to the region was superior to that of the British, since René-Robert Cavelier, Sieur de La Salle had explored the Ohio Country nearly a century earlier.
Even before Washington returned, Dinwiddie had sent a company of 40 men under William Trent to that point, where in the early months of 1754 they began construction of a small stockaded fort. Governor Duquesne sent additional French forces under Claude-Pierre Pecaudy de Contrecœur to relieve Saint-Pierre during the same period, and Contrecœur led 500 men south from Fort Venango on April 5, 1754. When these forces arrived at the fort on April 16, Contrecœur generously allowed Trent's small company to withdraw. He purchased their construction tools to continue building what became Fort Duquesne.
After Washington had returned to Williamsburg, Dinwiddie ordered him to lead a larger force to assist Trent in his work. While en route, Washington learned of Trent's retreat. Since Tanaghrisson had promised support to the British, Washington continued toward Fort Duquesne and met with the Mingo leader. Learning of a French scouting party in the area, Washington, with Tanaghrisson and his party, surprised the Canadians on May 28 in what became known as the Battle of Jumonville Glen. They killed many of the Canadians, including their commanding officer, Joseph Coulon de Jumonville, whose head was reportedly split open by Tanaghrisson with a tomahawk. The historian Fred Anderson suggests that Tanaghrisson was acting to gain the support of the British and regain authority over his own people. They had been inclined to support the French, with whom they had long trading relationships. One of Tanaghrisson's men told Contrecoeur that Jumonville had been killed by British musket fire.
News of the two battles reached England in August. After several months of negotiations, the government of the Duke of Newcastle decided to send an army expedition the following year to dislodge the French. They chose Major General Edward Braddock to lead the expedition. Word of the British military plans leaked to France well before Braddock's departure for North America. In response, King Louis XV dispatched six regiments to New France under the command of Baron Dieskau in 1755. The British, intending to blockade French ports, sent out their fleet in February 1755, but the French fleet had already sailed. Admiral Edward Hawke detached a fast squadron to North America in an attempt to intercept the French.
An early important political response to the opening of hostilities was the convening of the Albany Congress in June and July, 1754. The goal of the congress was to formalize a unified front in trade and negotiations with various Indians, since allegiance of the various tribes and nations was seen to be pivotal in the success in the war that was unfolding. The plan that the delegates agreed to was never ratified by the colonial legislatures nor approved of by the crown. Nevertheless, the format of the congress and many specifics of the plan became the prototype for confederation during the War of Independence.
Braddock (with George Washington as one of his aides) led about 1,500 army troops and provincial militia on an expedition in June 1755 to take Fort Duquesne. The expedition was a disaster. It was attacked by French and Indian soldiers ambushing them from up in trees and behind logs. Braddock called for a retreat. He was killed. Approximately 1,000 British soldiers were killed or injured. The remaining 500 British troops, led by George Washington, retreated to Virginia. Two future opponents in the American Revolutionary War, Washington and Thomas Gage, played key roles in organizing the retreat.
The French acquired a copy of the British war plans, including the activities of Shirley and Johnson. Shirley's efforts to fortify Oswego were bogged down in logistical difficulties, exacerbated by Shirley's inexperience in managing large expeditions. In conjunction, Shirley was made aware that the French were massing for an attack on Fort Oswego in his absence when he planned to attack Fort Niagara. As a response, Shirley left garrisons at Oswego, Fort Bull, and Fort Williams (the latter two located on the Oneida Carry between the Mohawk River and Wood Creek at present-day Rome, New York). Supplies for use in the projected attack on Niagara were cached at Fort Bull.
Johnson's expedition was better organized than Shirley's, which was noticed by New France's governor, the Marquis de Vaudreuil. He had primarily been concerned about the extended supply line to the forts on the Ohio, and had sent Baron Dieskau to lead the defenses at Frontenac against Shirley's expected attack. When Johnson was seen as the larger threat, Vaudreuil sent Dieskau to Fort St. Frédéric to meet that threat. Dieskau planned to attack the British encampment at Fort Edward at the upper end of navigation on the Hudson River, but Johnson had strongly fortified it, and Dieskau's Indian support was reluctant to attack. The two forces finally met in the bloody Battle of Lake George between Fort Edward and Fort William Henry. The battle ended inconclusively, with both sides withdrawing from the field. Johnson's advance stopped at Fort William Henry, and the French withdrew to Ticonderoga Point, where they began the construction of Fort Carillon (later renamed Fort Ticonderoga after British capture in 1759).
Colonel Monckton, in the sole British success that year, captured Fort Beauséjour in June 1755, cutting the French fortress at Louisbourg off from land-based reinforcements. To cut vital supplies to Louisbourg, Nova Scotia's Governor Charles Lawrence ordered the deportation of the French-speaking Acadian population from the area. Monckton's forces, including companies of Rogers' Rangers, forcibly removed thousands of Acadians, chasing down many who resisted, and sometimes committing atrocities. More than any other factor, the cutting off of supplies to Louisbourg led to its demise. The Acadian resistance, in concert with native allies, including the Mi'kmaq, was sometimes quite stiff, with ongoing frontier raids (against Dartmouth and Lunenburg among others). Other than the campaigns to expel the Acadians (ranging around the Bay of Fundy, on the Petitcodiac and St. John rivers, and Île Saint-Jean), the only clashes of any size were at Petitcodiac in 1755 and at Bloody Creek near Annapolis Royal in 1757.
Following the death of Braddock, William Shirley assumed command of British forces in North America. At a meeting in Albany in December 1755, he laid out his plans for 1756. In addition to renewing the efforts to capture Niagara, Crown Point and Duquesne, he proposed attacks on Fort Frontenac on the north shore of Lake Ontario and an expedition through the wilderness of the Maine district and down the Chaudière River to attack the city of Quebec. Bogged down by disagreements and disputes with others, including William Johnson and New York's Governor Sir Charles Hardy, Shirley's plan had little support.
Newcastle replaced him in January 1756 with Lord Loudoun, with Major General James Abercrombie as his second in command. Neither of these men had as much campaign experience as the trio of officers France sent to North America. French regular army reinforcements arrived in New France in May 1756, led by Major General Louis-Joseph de Montcalm and seconded by the Chevalier de Lévis and Colonel François-Charles de Bourlamaque, all experienced veterans from the War of the Austrian Succession. During that time in Europe, on May 18, 1756, England formally declared war on France, which expanded the war into Europe, which was later to be known as the Seven Years' War.
Governor Vaudreuil, who harboured ambitions to become the French commander in chief (in addition to his role as governor), acted during the winter of 1756 before those reinforcements arrived. Scouts had reported the weakness of the British supply chain, so he ordered an attack against the forts Shirley had erected at the Oneida Carry. In the March Battle of Fort Bull, French forces destroyed the fort and large quantities of supplies, including 45,000 pounds of gunpowder. They set back any British hopes for campaigns on Lake Ontario, and endangered the Oswego garrison, already short on supplies. French forces in the Ohio valley also continued to intrigue with Indians throughout the area, encouraging them to raid frontier settlements. This led to ongoing alarms along the western frontiers, with streams of refugees returning east to get away from the action.
The new British command was not in place until July. When he arrived in Albany, Abercrombie refused to take any significant actions until Loudoun approved them. Montcalm took bold action against his inertia. Building on Vaudreuil's work harassing the Oswego garrison, Montcalm executed a strategic feint by moving his headquarters to Ticonderoga, as if to presage another attack along Lake George. With Abercrombie pinned down at Albany, Montcalm slipped away and led the successful attack on Oswego in August. In the aftermath, Montcalm and the Indians under his command disagreed about the disposition of prisoners' personal effects. The Europeans did not consider them prizes and prevented the Indians from stripping the prisoners of their valuables, which angered the Indians.
Loudoun, a capable administrator but a cautious field commander, planned one major operation for 1757: an attack on New France's capital, Quebec. Leaving a sizable force at Fort William Henry to distract Montcalm, he began organizing for the expedition to Quebec. He was then ordered by William Pitt, the Secretary of State responsible for the colonies, to attack Louisbourg first. Beset by delays of all kinds, the expedition was finally ready to sail from Halifax, Nova Scotia in early August. In the meantime French ships had escaped the British blockade of the French coast, and a fleet outnumbering the British one awaited Loudoun at Louisbourg. Faced with this strength, Loudoun returned to New York amid news that a massacre had occurred at Fort William Henry.
French irregular forces (Canadian scouts and Indians) harassed Fort William Henry throughout the first half of 1757. In January they ambushed British rangers near Ticonderoga. In February they launched a daring raid against the position across the frozen Lake George, destroying storehouses and buildings outside the main fortification. In early August, Montcalm and 7,000 troops besieged the fort, which capitulated with an agreement to withdraw under parole. When the withdrawal began, some of Montcalm's Indian allies, angered at the lost opportunity for loot, attacked the British column, killing and capturing several hundred men, women, children, and slaves. The aftermath of the siege may have contributed to the transmission of smallpox into remote Indian populations; as some Indians were reported to have traveled from beyond the Mississippi to participate in the campaign and returned afterward having been exposed to European carriers.
Vaudreuil and Montcalm were minimally resupplied in 1758, as the British blockade of the French coastline limited French shipping. The situation in New France was further exacerbated by a poor harvest in 1757, a difficult winter, and the allegedly corrupt machinations of François Bigot, the intendant of the territory. His schemes to supply the colony inflated prices and were believed by Montcalm to line his pockets and those of his associates. A massive outbreak of smallpox among western tribes led many of them to stay away from trading in 1758. While many parties to the conflict blamed others (the Indians blamed the French for bringing "bad medicine" as well as denying them prizes at Fort William Henry), the disease was probably spread through the crowded conditions at William Henry after the battle. Montcalm focused his meager resources on the defense of the St. Lawrence, with primary defenses at Carillon, Quebec, and Louisbourg, while Vaudreuil argued unsuccessfully for a continuation of the raiding tactics that had worked quite effectively in previous years.
The British failures in North America, combined with other failures in the European theater, led to the fall from power of Newcastle and his principal military advisor, the Duke of Cumberland. Newcastle and Pitt joined in an uneasy coalition in which Pitt dominated the military planning. He embarked on a plan for the 1758 campaign that was largely developed by Loudoun. He had been replaced by Abercrombie as commander in chief after the failures of 1757. Pitt's plan called for three major offensive actions involving large numbers of regular troops, supported by the provincial militias, aimed at capturing the heartlands of New France. Two of the expeditions were successful, with Fort Duquesne and Louisbourg falling to sizable British forces.
The third invasion was stopped with the improbable French victory in the Battle of Carillon, in which 3,600 Frenchmen famously and decisively defeated Abercrombie's force of 18,000 regulars, militia and Native American allies outside the fort the French called Carillon and the British called Ticonderoga. Abercrombie saved something from the disaster when he sent John Bradstreet on an expedition that successfully destroyed Fort Frontenac, including caches of supplies destined for New France's western forts and furs destined for Europe. Abercrombie was recalled and replaced by Jeffery Amherst, victor at Louisbourg.
In the aftermath of generally poor French results in most theaters of the Seven Years' War in 1758, France's new foreign minister, the duc de Choiseul, decided to focus on an invasion of Britain, to draw British resources away from North America and the European mainland. The invasion failed both militarily and politically, as Pitt again planned significant campaigns against New France, and sent funds to Britain's ally on the mainland, Prussia, and the French Navy failed in the 1759 naval battles at Lagos and Quiberon Bay. In one piece of good fortune, some French supply ships managed to depart France, eluding the British blockade of the French coast.
British victories continued in all theaters in the Annus Mirabilis of 1759, when they finally captured Ticonderoga, James Wolfe defeated Montcalm at Quebec (in a battle that claimed the lives of both commanders), and victory at Fort Niagara successfully cut off the French frontier forts further to the west and south. The victory was made complete in 1760 when, despite losing outside Quebec City in the Battle of Sainte-Foy, the British were able to prevent the arrival of French relief ships in the naval Battle of the Restigouche while armies marched on Montreal from three sides.
In September 1760, and before any hostilities erupted, Governor Vaudreuil negotiated from Montreal a capitulation with General Amherst. Amherst granted Vaudreuil's request that any French residents who chose to remain in the colony would be given freedom to continue worshiping in their Roman Catholic tradition, continued ownership of their property, and the right to remain undisturbed in their homes. The British provided medical treatment for the sick and wounded French soldiers and French regular troops were returned to France aboard British ships with an agreement that they were not to serve again in the present war.
The war in North America officially ended with the signing of the Treaty of Paris on 10 February 1763, and war in the European theatre of the Seven Years' War was settled by the Treaty of Hubertusburg on 15 February 1763. The British offered France the choice of surrendering either its continental North American possessions east of the Mississippi or the Caribbean islands of Guadeloupe and Martinique, which had been occupied by the British. France chose to cede the former, but was able to negotiate the retention of Saint Pierre and Miquelon, two small islands in the Gulf of St. Lawrence, along with fishing rights in the area. They viewed the economic value of the Caribbean islands' sugar cane to be greater and easier to defend than the furs from the continent. The contemporaneous French philosopher Voltaire referred to Canada disparagingly as nothing more than a few acres of snow. The British, for their part, were happy to take New France, as defence of their North American colonies would no longer be an issue and also because they already had ample places from which to obtain sugar. Spain, which traded Florida to Britain to regain Cuba, also gained Louisiana, including New Orleans, from France in compensation for its losses. Great Britain and Spain also agreed that navigation on the Mississippi River was to be open to vessels of all nations.
Britain gained control of French Canada and Acadia, colonies containing approximately 80,000 primarily French-speaking Roman Catholic residents. The deportation of Acadians beginning in 1755 resulted in land made available to migrants from Europe and the colonies further south. The British resettled many Acadians throughout its North American provinces, but many went to France, and some went to New Orleans, which they had expected to remain French. Some were sent to colonize places as diverse as French Guiana and the Falkland Islands; these latter efforts were unsuccessful. Others migrated to places like Saint-Domingue, and fled to New Orleans after the Haitian Revolution. The Louisiana population contributed to the founding of the modern Cajun population. (The French word "Acadien" evolved to "Cadien", then to "Cajun".)
Following the treaty, King George III issued the Royal Proclamation of 1763 on October 7, 1763, which outlined the division and administration of the newly conquered territory, and to some extent continues to govern relations between the government of modern Canada and the First Nations. Included in its provisions was the reservation of lands west of the Appalachian Mountains to its Indian population, a demarcation that was at best a temporary impediment to a rising tide of westward-bound settlers. The proclamation also contained provisions that prevented civic participation by the Roman Catholic Canadians. When accommodations were made in the Quebec Act in 1774 to address this and other issues, religious concerns were raised in the largely Protestant Thirteen Colonies over the advance of "popery"; the Act maintained French Civil law, including the seigneurial system, a medieval code soon to be removed from France within a generation by the French Revolution.
For many native populations, the elimination of French power in North America meant the disappearance of a strong ally and counterweight to British expansion, leading to their ultimate dispossession. The Ohio Country was particularly vulnerable to legal and illegal settlement due to the construction of military roads to the area by Braddock and Forbes. Although the Spanish takeover of the Louisiana territory (which was not completed until 1769) had modest repercussions, the British takeover of Spanish Florida resulted in the westward migration of tribes that did not want to do business with the British, and a rise in tensions between the Choctaw and the Creek, historic enemies whose divisions the British at times exploited. The change of control in Florida also prompted most of its Spanish Catholic population to leave. Most went to Cuba, including the entire governmental records from St. Augustine, although some Christianized Yamasee were resettled to the coast of Mexico.
Philosophers in antiquity used the concept of force in the study of stationary and moving objects and simple machines, but thinkers such as Aristotle and Archimedes retained fundamental errors in understanding force. In part this was due to an incomplete understanding of the sometimes non-obvious force of friction, and a consequently inadequate view of the nature of natural motion. A fundamental error was the belief that a force is required to maintain motion, even at a constant velocity. Most of the previous misunderstandings about motion and force were eventually corrected by Galileo Galilei and Sir Isaac Newton. With his mathematical insight, Sir Isaac Newton formulated laws of motion that were not improved-on for nearly three hundred years. By the early 20th century, Einstein developed a theory of relativity that correctly predicted the action of forces on objects with increasing momenta near the speed of light, and also provided insight into the forces produced by gravitation and inertia.
With modern insights into quantum mechanics and technology that can accelerate particles close to the speed of light, particle physics has devised a Standard Model to describe forces between particles smaller than atoms. The Standard Model predicts that exchanged particles called gauge bosons are the fundamental means by which forces are emitted and absorbed. Only four main interactions are known: in order of decreasing strength, they are: strong, electromagnetic, weak, and gravitational.:2–10:79 High-energy particle physics observations made during the 1970s and 1980s confirmed that the weak and electromagnetic forces are expressions of a more fundamental electroweak interaction.
Aristotle provided a philosophical discussion of the concept of a force as an integral part of Aristotelian cosmology. In Aristotle's view, the terrestrial sphere contained four elements that come to rest at different "natural places" therein. Aristotle believed that motionless objects on Earth, those composed mostly of the elements earth and water, to be in their natural place on the ground and that they will stay that way if left alone. He distinguished between the innate tendency of objects to find their "natural place" (e.g., for heavy bodies to fall), which led to "natural motion", and unnatural or forced motion, which required continued application of a force. This theory, based on the everyday experience of how objects move, such as the constant application of a force needed to keep a cart moving, had conceptual trouble accounting for the behavior of projectiles, such as the flight of arrows. The place where the archer moves the projectile was at the start of the flight, and while the projectile sailed through the air, no discernible efficient cause acts on it. Aristotle was aware of this problem and proposed that the air displaced through the projectile's path carries the projectile to its target. This explanation demands a continuum like air for change of place in general.
The shortcomings of Aristotelian physics would not be fully corrected until the 17th century work of Galileo Galilei, who was influenced by the late Medieval idea that objects in forced motion carried an innate force of impetus. Galileo constructed an experiment in which stones and cannonballs were both rolled down an incline to disprove the Aristotelian theory of motion early in the 17th century. He showed that the bodies were accelerated by gravity to an extent that was independent of their mass and argued that objects retain their velocity unless acted on by a force, for example friction.
Newton's First Law of Motion states that objects continue to move in a state of constant velocity unless acted upon by an external net force or resultant force. This law is an extension of Galileo's insight that constant velocity was associated with a lack of net force (see a more detailed description of this below). Newton proposed that every object with mass has an innate inertia that functions as the fundamental equilibrium "natural state" in place of the Aristotelian idea of the "natural state of rest". That is, the first law contradicts the intuitive Aristotelian belief that a net force is required to keep an object moving with constant velocity. By making rest physically indistinguishable from non-zero constant velocity, Newton's First Law directly connects inertia with the concept of relative velocities. Specifically, in systems where objects are moving with different velocities, it is impossible to determine which object is "in motion" and which object is "at rest". In other words, to phrase matters more technically, the laws of physics are the same in every inertial frame of reference, that is, in all frames related by a Galilean transformation.
For instance, while traveling in a moving vehicle at a constant velocity, the laws of physics do not change from being at rest. A person can throw a ball straight up in the air and catch it as it falls down without worrying about applying a force in the direction the vehicle is moving. This is true even though another person who is observing the moving vehicle pass by also observes the ball follow a curving parabolic path in the same direction as the motion of the vehicle. It is the inertia of the ball associated with its constant velocity in the direction of the vehicle's motion that ensures the ball continues to move forward even as it is thrown up and falls back down. From the perspective of the person in the car, the vehicle and everything inside of it is at rest: It is the outside world that is moving with a constant speed in the opposite direction. Since there is no experiment that can distinguish whether it is the vehicle that is at rest or the outside world that is at rest, the two situations are considered to be physically indistinguishable. Inertia therefore applies equally well to constant velocity motion as it does to rest.
The concept of inertia can be further generalized to explain the tendency of objects to continue in many different forms of constant motion, even those that are not strictly constant velocity. The rotational inertia of planet Earth is what fixes the constancy of the length of a day and the length of a year. Albert Einstein extended the principle of inertia further when he explained that reference frames subject to constant acceleration, such as those free-falling toward a gravitating object, were physically equivalent to inertial reference frames. This is why, for example, astronauts experience weightlessness when in free-fall orbit around the Earth, and why Newton's Laws of Motion are more easily discernible in such environments. If an astronaut places an object with mass in mid-air next to himself, it will remain stationary with respect to the astronaut due to its inertia. This is the same thing that would occur if the astronaut and the object were in intergalactic space with no net force of gravity acting on their shared reference frame. This principle of equivalence was one of the foundational underpinnings for the development of the general theory of relativity.
Newton's Second Law asserts the direct proportionality of acceleration to force and the inverse proportionality of acceleration to mass. Accelerations can be defined through kinematic measurements. However, while kinematics are well-described through reference frame analysis in advanced physics, there are still deep questions that remain as to what is the proper definition of mass. General relativity offers an equivalence between space-time and mass, but lacking a coherent theory of quantum gravity, it is unclear as to how or whether this connection is relevant on microscales. With some justification, Newton's second law can be taken as a quantitative definition of mass by writing the law as an equality; the relative units of force and mass then are fixed.
Newton's Third Law is a result of applying symmetry to situations where forces can be attributed to the presence of different objects. The third law means that all forces are interactions between different bodies,[Note 3] and thus that there is no such thing as a unidirectional force or a force that acts on only one body. Whenever a first body exerts a force F on a second body, the second body exerts a force −F on the first body. F and −F are equal in magnitude and opposite in direction. This law is sometimes referred to as the action-reaction law, with F called the "action" and −F the "reaction". The action and the reaction are simultaneous:
This means that in a closed system of particles, there are no internal forces that are unbalanced. That is, the action-reaction force shared between any two objects in a closed system will not cause the center of mass of the system to accelerate. The constituent objects only accelerate with respect to each other, the system itself remains unaccelerated. Alternatively, if an external force acts on the system, then the center of mass will experience an acceleration proportional to the magnitude of the external force divided by the mass of the system.:19-1
Since forces are perceived as pushes or pulls, this can provide an intuitive understanding for describing forces. As with other physical concepts (e.g. temperature), the intuitive understanding of forces is quantified using precise operational definitions that are consistent with direct observations and compared to a standard measurement scale. Through experimentation, it is determined that laboratory measurements of forces are fully consistent with the conceptual definition of force offered by Newtonian mechanics.
Forces act in a particular direction and have sizes dependent upon how strong the push or pull is. Because of these characteristics, forces are classified as "vector quantities". This means that forces follow a different set of mathematical rules than physical quantities that do not have direction (denoted scalar quantities). For example, when determining what happens when two forces act on the same object, it is necessary to know both the magnitude and the direction of both forces to calculate the result. If both of these pieces of information are not known for each force, the situation is ambiguous. For example, if you know that two people are pulling on the same rope with known magnitudes of force but you do not know which direction either person is pulling, it is impossible to determine what the acceleration of the rope will be. The two people could be pulling against each other as in tug of war or the two people could be pulling in the same direction. In this simple one-dimensional example, without knowing the direction of the forces it is impossible to decide whether the net force is the result of adding the two force magnitudes or subtracting one from the other. Associating forces with vectors avoids such problems.
Historically, forces were first quantitatively investigated in conditions of static equilibrium where several forces canceled each other out. Such experiments demonstrate the crucial properties that forces are additive vector quantities: they have magnitude and direction. When two forces act on a point particle, the resulting force, the resultant (also called the net force), can be determined by following the parallelogram rule of vector addition: the addition of two vectors represented by sides of a parallelogram, gives an equivalent resultant vector that is equal in magnitude and direction to the transversal of the parallelogram. The magnitude of the resultant varies from the difference of the magnitudes of the two forces to their sum, depending on the angle between their lines of action. However, if the forces are acting on an extended body, their respective lines of application must also be specified in order to account for their effects on the motion of the body.
As well as being added, forces can also be resolved into independent components at right angles to each other. A horizontal force pointing northeast can therefore be split into two forces, one pointing north, and one pointing east. Summing these component forces using vector addition yields the original force. Resolving force vectors into components of a set of basis vectors is often a more mathematically clean way to describe forces than using magnitudes and directions. This is because, for orthogonal components, the components of the vector sum are uniquely determined by the scalar addition of the components of the individual vectors. Orthogonal components are independent of each other because forces acting at ninety degrees to each other have no effect on the magnitude or direction of the other. Choosing a set of orthogonal basis vectors is often done by considering what set of basis vectors will make the mathematics most convenient. Choosing a basis vector that is in the same direction as one of the forces is desirable, since that force would then have only one non-zero component. Orthogonal force vectors can be three-dimensional with the third component being at right-angles to the other two.
Pushing against an object on a frictional surface can result in a situation where the object does not move because the applied force is opposed by static friction, generated between the object and the table surface. For a situation with no movement, the static friction force exactly balances the applied force resulting in no acceleration. The static friction increases or decreases in response to the applied force up to an upper limit determined by the characteristics of the contact between the surface and the object.
A static equilibrium between two forces is the most usual way of measuring forces, using simple devices such as weighing scales and spring balances. For example, an object suspended on a vertical spring scale experiences the force of gravity acting on the object balanced by a force applied by the "spring reaction force", which equals the object's weight. Using such tools, some quantitative force laws were discovered: that the force of gravity is proportional to volume for objects of constant density (widely exploited for millennia to define standard weights); Archimedes' principle for buoyancy; Archimedes' analysis of the lever; Boyle's law for gas pressure; and Hooke's law for springs. These were all formulated and experimentally verified before Isaac Newton expounded his Three Laws of Motion.
Dynamic equilibrium was first described by Galileo who noticed that certain assumptions of Aristotelian physics were contradicted by observations and logic. Galileo realized that simple velocity addition demands that the concept of an "absolute rest frame" did not exist. Galileo concluded that motion in a constant velocity was completely equivalent to rest. This was contrary to Aristotle's notion of a "natural state" of rest that objects with mass naturally approached. Simple experiments showed that Galileo's understanding of the equivalence of constant velocity and rest were correct. For example, if a mariner dropped a cannonball from the crow's nest of a ship moving at a constant velocity, Aristotelian physics would have the cannonball fall straight down while the ship moved beneath it. Thus, in an Aristotelian universe, the falling cannonball would land behind the foot of the mast of a moving ship. However, when this experiment is actually conducted, the cannonball always falls at the foot of the mast, as if the cannonball knows to travel with the ship despite being separated from it. Since there is no forward horizontal force being applied on the cannonball as it falls, the only conclusion left is that the cannonball continues to move with the same velocity as the boat as it falls. Thus, no force is required to keep the cannonball moving at the constant forward velocity.
A simple case of dynamic equilibrium occurs in constant velocity motion across a surface with kinetic friction. In such a situation, a force is applied in the direction of motion while the kinetic friction force exactly opposes the applied force. This results in zero net force, but since the object started with a non-zero velocity, it continues to move with a non-zero velocity. Aristotle misinterpreted this motion as being caused by the applied force. However, when kinetic friction is taken into consideration it is clear that there is no net force causing constant velocity motion.
The notion "force" keeps its meaning in quantum mechanics, though one is now dealing with operators instead of classical variables and though the physics is now described by the Schrödinger equation instead of Newtonian equations. This has the consequence that the results of a measurement are now sometimes "quantized", i.e. they appear in discrete portions. This is, of course, difficult to imagine in the context of "forces". However, the potentials V(x,y,z) or fields, from which the forces generally can be derived, are treated similar to classical position variables, i.e., .
However, already in quantum mechanics there is one "caveat", namely the particles acting onto each other do not only possess the spatial variable, but also a discrete intrinsic angular momentum-like variable called the "spin", and there is the Pauli principle relating the space and the spin variables. Depending on the value of the spin, identical particles split into two different classes, fermions and bosons. If two identical fermions (e.g. electrons) have a symmetric spin function (e.g. parallel spins) the spatial variables must be antisymmetric (i.e. they exclude each other from their places much as if there was a repulsive force), and vice versa, i.e. for antiparallel spins the position variables must be symmetric (i.e. the apparent force must be attractive). Thus in the case of two fermions there is a strictly negative correlation between spatial and spin variables, whereas for two bosons (e.g. quanta of electromagnetic waves, photons) the correlation is strictly positive.
In modern particle physics, forces and the acceleration of particles are explained as a mathematical by-product of exchange of momentum-carrying gauge bosons. With the development of quantum field theory and general relativity, it was realized that force is a redundant concept arising from conservation of momentum (4-momentum in relativity and momentum of virtual particles in quantum electrodynamics). The conservation of momentum can be directly derived from the homogeneity or symmetry of space and so is usually considered more fundamental than the concept of a force. Thus the currently known fundamental forces are considered more accurately to be "fundamental interactions".:199–128 When particle A emits (creates) or absorbs (annihilates) virtual particle B, a momentum conservation results in recoil of particle A making impression of repulsion or attraction between particles A A' exchanging by B. This description applies to all forces arising from fundamental interactions. While sophisticated mathematical descriptions are needed to predict, in full detail, the accurate result of such interactions, there is a conceptually simple way to describe such interactions through the use of Feynman diagrams. In a Feynman diagram, each matter particle is represented as a straight line (see world line) traveling through time, which normally increases up or to the right in the diagram. Matter and anti-matter particles are identical except for their direction of propagation through the Feynman diagram. World lines of particles intersect at interaction vertices, and the Feynman diagram represents any force arising from an interaction as occurring at the vertex with an associated instantaneous change in the direction of the particle world lines. Gauge bosons are emitted away from the vertex as wavy lines and, in the case of virtual particle exchange, are absorbed at an adjacent vertex.
All of the forces in the universe are based on four fundamental interactions. The strong and weak forces are nuclear forces that act only at very short distances, and are responsible for the interactions between subatomic particles, including nucleons and compound nuclei. The electromagnetic force acts between electric charges, and the gravitational force acts between masses. All other forces in nature derive from these four fundamental interactions. For example, friction is a manifestation of the electromagnetic force acting between the atoms of two surfaces, and the Pauli exclusion principle, which does not permit atoms to pass through each other. Similarly, the forces in springs, modeled by Hooke's law, are the result of electromagnetic forces and the Exclusion Principle acting together to return an object to its equilibrium position. Centrifugal forces are acceleration forces that arise simply from the acceleration of rotating frames of reference.:12-11:359
The development of fundamental theories for forces proceeded along the lines of unification of disparate ideas. For example, Isaac Newton unified the force responsible for objects falling at the surface of the Earth with the force responsible for the orbits of celestial mechanics in his universal theory of gravitation. Michael Faraday and James Clerk Maxwell demonstrated that electric and magnetic forces were unified through one consistent theory of electromagnetism. In the 20th century, the development of quantum mechanics led to a modern understanding that the first three fundamental forces (all except gravity) are manifestations of matter (fermions) interacting by exchanging virtual particles called gauge bosons. This standard model of particle physics posits a similarity between the forces and led scientists to predict the unification of the weak and electromagnetic forces in electroweak theory subsequently confirmed by observation. The complete formulation of the standard model predicts an as yet unobserved Higgs mechanism, but observations such as neutrino oscillations indicate that the standard model is incomplete. A Grand Unified Theory allowing for the combination of the electroweak interaction with the strong force is held out as a possibility with candidate theories such as supersymmetry proposed to accommodate some of the outstanding unsolved problems in physics. Physicists are still attempting to develop self-consistent unification models that would combine all four fundamental interactions into a theory of everything. Einstein tried and failed at this endeavor, but currently the most popular approach to answering this question is string theory.:212–219
What we now call gravity was not identified as a universal force until the work of Isaac Newton. Before Newton, the tendency for objects to fall towards the Earth was not understood to be related to the motions of celestial objects. Galileo was instrumental in describing the characteristics of falling objects by determining that the acceleration of every object in free-fall was constant and independent of the mass of the object. Today, this acceleration due to gravity towards the surface of the Earth is usually designated as and has a magnitude of about 9.81 meters per second squared (this measurement is taken from sea level and may vary depending on location), and points toward the center of the Earth. This observation means that the force of gravity on an object at the Earth's surface is directly proportional to the object's mass. Thus an object that has a mass of will experience a force:
Newton came to realize that the effects of gravity might be observed in different ways at larger distances. In particular, Newton determined that the acceleration of the Moon around the Earth could be ascribed to the same force of gravity if the acceleration due to gravity decreased as an inverse square law. Further, Newton realized that the acceleration due to gravity is proportional to the mass of the attracting body. Combining these ideas gives a formula that relates the mass () and the radius () of the Earth to the gravitational acceleration:
In this equation, a dimensional constant is used to describe the relative strength of gravity. This constant has come to be known as Newton's Universal Gravitation Constant, though its value was unknown in Newton's lifetime. Not until 1798 was Henry Cavendish able to make the first measurement of using a torsion balance; this was widely reported in the press as a measurement of the mass of the Earth since knowing could allow one to solve for the Earth's mass given the above equation. Newton, however, realized that since all celestial bodies followed the same laws of motion, his law of gravity had to be universal. Succinctly stated, Newton's Law of Gravitation states that the force on a spherical object of mass due to the gravitational pull of mass is
It was only the orbit of the planet Mercury that Newton's Law of Gravitation seemed not to fully explain. Some astrophysicists predicted the existence of another planet (Vulcan) that would explain the discrepancies; however, despite some early indications, no such planet could be found. When Albert Einstein formulated his theory of general relativity (GR) he turned his attention to the problem of Mercury's orbit and found that his theory added a correction, which could account for the discrepancy. This was the first time that Newton's Theory of Gravity had been shown to be less correct than an alternative.
Since then, and so far, general relativity has been acknowledged as the theory that best explains gravity. In GR, gravitation is not viewed as a force, but rather, objects moving freely in gravitational fields travel under their own inertia in straight lines through curved space-time – defined as the shortest space-time path between two space-time events. From the perspective of the object, all motion occurs as if there were no gravitation whatsoever. It is only when observing the motion in a global sense that the curvature of space-time can be observed and the force is inferred from the object's curved path. Thus, the straight line path in space-time is seen as a curved line in space, and it is called the ballistic trajectory of the object. For example, a basketball thrown from the ground moves in a parabola, as it is in a uniform gravitational field. Its space-time trajectory (when the extra ct dimension is added) is almost a straight line, slightly curved (with the radius of curvature of the order of few light-years). The time derivative of the changing momentum of the object is what we label as "gravitational force".
Through combining the definition of electric current as the time rate of change of electric charge, a rule of vector multiplication called Lorentz's Law describes the force on a charge moving in a magnetic field. The connection between electricity and magnetism allows for the description of a unified electromagnetic force that acts on a charge. This force can be written as a sum of the electrostatic force (due to the electric field) and the magnetic force (due to the magnetic field). Fully stated, this is the law:
The origin of electric and magnetic fields would not be fully explained until 1864 when James Clerk Maxwell unified a number of earlier theories into a set of 20 scalar equations, which were later reformulated into 4 vector equations by Oliver Heaviside and Josiah Willard Gibbs. These "Maxwell Equations" fully described the sources of the fields as being stationary and moving charges, and the interactions of the fields themselves. This led Maxwell to discover that electric and magnetic fields could be "self-generating" through a wave that traveled at a speed that he calculated to be the speed of light. This insight united the nascent fields of electromagnetic theory with optics and led directly to a complete description of the electromagnetic spectrum.
However, attempting to reconcile electromagnetic theory with two observations, the photoelectric effect, and the nonexistence of the ultraviolet catastrophe, proved troublesome. Through the work of leading theoretical physicists, a new theory of electromagnetism was developed using quantum mechanics. This final modification to electromagnetic theory ultimately led to quantum electrodynamics (or QED), which fully describes all electromagnetic phenomena as being mediated by wave–particles known as photons. In QED, photons are the fundamental exchange particle, which described all interactions relating to electromagnetism including the electromagnetic force.[Note 4]
It is a common misconception to ascribe the stiffness and rigidity of solid matter to the repulsion of like charges under the influence of the electromagnetic force. However, these characteristics actually result from the Pauli exclusion principle.[citation needed] Since electrons are fermions, they cannot occupy the same quantum mechanical state as other electrons. When the electrons in a material are densely packed together, there are not enough lower energy quantum mechanical states for them all, so some of them must be in higher energy states. This means that it takes energy to pack them together. While this effect is manifested macroscopically as a structural force, it is technically only the result of the existence of a finite set of electron states.
The strong force only acts directly upon elementary particles. However, a residual of the force is observed between hadrons (the best known example being the force that acts between nucleons in atomic nuclei) as the nuclear force. Here the strong force acts indirectly, transmitted as gluons, which form part of the virtual pi and rho mesons, which classically transmit the nuclear force (see this topic for more). The failure of many searches for free quarks has shown that the elementary particles affected are not directly observable. This phenomenon is called color confinement.
The weak force is due to the exchange of the heavy W and Z bosons. Its most familiar effect is beta decay (of neutrons in atomic nuclei) and the associated radioactivity. The word "weak" derives from the fact that the field strength is some 1013 times less than that of the strong force. Still, it is stronger than gravity over short distances. A consistent electroweak theory has also been developed, which shows that electromagnetic forces and the weak force are indistinguishable at a temperatures in excess of approximately 1015 kelvins. Such temperatures have been probed in modern particle accelerators and show the conditions of the universe in the early moments of the Big Bang.
The normal force is due to repulsive forces of interaction between atoms at close contact. When their electron clouds overlap, Pauli repulsion (due to fermionic nature of electrons) follows resulting in the force that acts in a direction normal to the surface interface between two objects.:93 The normal force, for example, is responsible for the structural integrity of tables and floors as well as being the force that responds whenever an external force pushes on a solid object. An example of the normal force in action is the impact force on an object crashing into an immobile surface.
Tension forces can be modeled using ideal strings that are massless, frictionless, unbreakable, and unstretchable. They can be combined with ideal pulleys, which allow ideal strings to switch physical direction. Ideal strings transmit tension forces instantaneously in action-reaction pairs so that if two objects are connected by an ideal string, any force directed along the string by the first object is accompanied by a force directed along the string in the opposite direction by the second object. By connecting the same string multiple times to the same object through the use of a set-up that uses movable pulleys, the tension force on a load can be multiplied. For every string that acts on a load, another factor of the tension force in the string acts on the load. However, even though such machines allow for an increase in force, there is a corresponding increase in the length of string that must be displaced in order to move the load. These tandem effects result ultimately in the conservation of mechanical energy since the work done on the load is the same no matter how complicated the machine.
Newton's laws and Newtonian mechanics in general were first developed to describe how forces affect idealized point particles rather than three-dimensional objects. However, in real life, matter has extended structure and forces that act on one part of an object might affect other parts of an object. For situations where lattice holding together the atoms in an object is able to flow, contract, expand, or otherwise change shape, the theories of continuum mechanics describe the way forces affect the material. For example, in extended fluids, differences in pressure result in forces being directed along the pressure gradients as follows:
where is the relevant cross-sectional area for the volume for which the stress-tensor is being calculated. This formalism includes pressure terms associated with forces that act normal to the cross-sectional area (the matrix diagonals of the tensor) as well as shear terms associated with forces that act parallel to the cross-sectional area (the off-diagonal elements). The stress tensor accounts for forces that cause all strains (deformations) including also tensile stresses and compressions.:133–134:38-1–38-11
Torque is the rotation equivalent of force in the same way that angle is the rotational equivalent for position, angular velocity for velocity, and angular momentum for momentum. As a consequence of Newton's First Law of Motion, there exists rotational inertia that ensures that all bodies maintain their angular momentum unless acted upon by an unbalanced torque. Likewise, Newton's Second Law of Motion can be used to derive an analogous equation for the instantaneous angular acceleration of the rigid body:
where is the mass of the object, is the velocity of the object and is the distance to the center of the circular path and is the unit vector pointing in the radial direction outwards from the center. This means that the unbalanced centripetal force felt by any object is always directed toward the center of the curving path. Such forces act perpendicular to the velocity vector associated with the motion of an object, and therefore do not change the speed of the object (magnitude of the velocity), but only the direction of the velocity vector. The unbalanced force that accelerates an object can be resolved into a component that is perpendicular to the path, and one that is tangential to the path. This yields both the tangential force, which accelerates the object by either slowing it down or speeding it up, and the radial (centripetal) force, which changes its direction.
A conservative force that acts on a closed system has an associated mechanical work that allows energy to convert only between kinetic or potential forms. This means that for a closed system, the net mechanical energy is conserved whenever a conservative force acts on the system. The force, therefore, is related directly to the difference in potential energy between two different locations in space, and can be considered to be an artifact of the potential field in the same way that the direction and amount of a flow of water can be considered to be an artifact of the contour map of the elevation of an area.
For certain physical scenarios, it is impossible to model forces as being due to gradient of potentials. This is often due to macrophysical considerations that yield forces as arising from a macroscopic statistical average of microstates. For example, friction is caused by the gradients of numerous electrostatic potentials between the atoms, but manifests as a force model that is independent of any macroscale position vector. Nonconservative forces other than friction include other contact forces, tension, compression, and drag. However, for any sufficiently detailed description, all these forces are the results of conservative ones since each of these macroscopic forces are the net results of the gradients of microscopic potentials.

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