Historically, the French mechanic Laplace predicted: "A luminous star with a mass of 250 suns and a diameter of the earth will not allow any light to leave it because of its gravity. Because of this, the largest luminous object in the universe will not be seen by us. "
Black hole is a kind of celestial body with considerable mass, which is formed after the gravitational collapse after the death of nuclear energy. According to Newton's law of universal gravitation, a black hole is called a black hole because its first cosmic speed is too high for even light to escape.
The gravity of this area is very strong, and no matter can escape from this area, even the light is pulled back by its strong gravity, so the black hole itself will not emit light, but the black hole will not appear black like other objects that do not emit light. The gravity of a black hole can make the light behind appear in front, making you think it is transparent. Astronomers can find out the location of a black hole by observing the matter around it when it is attracted.
Electronic instruments can detect black holes.
Size and quality
Computer simulation of a black hole with the mass of the sun 10 times is formed by the gravitational collapse of a celestial body with the mass of 3.2 times that of the sun (stars with the mass less than the sun 1.4 will become white dwarfs). Astronomical observation shows that there are supermassive black holes in the center of many galaxies, including the Milky Way, whose mass is hundreds of millions of times that of the sun.
Einstein's general theory of relativity predicted the black hole solution. The simplest spherically symmetric solution is schwarzschild metric. This is the solution of Einstein's equation discovered by karl schwarzschild in 19 15.
According to Schwarzschild's solution, if the radius of a gravitational celestial body is less than a certain value, the celestial body will collapse, and this radius is called schwarzschild radius. The space-time of a celestial body below this radius is so curved that all the rays it emits will be attracted to the center of the celestial body, no matter from what direction. Because the theory of relativity points out that in any inertial coordinate system, the speed of matter cannot exceed the speed of light in vacuum, and any matter in celestial bodies below schwarzschild radius, including the components of gravitational celestial bodies, will collapse in the central part. Theoretically, a point with infinite density constitutes a gravitational singularity. Because even light can't escape from the black hole in schwarzschild radius, a typical black hole is absolutely "black".
temperature
The bigger the black hole, the lower the temperature.
characteristic
At present, there are only three physical quantities that can be measured in a black hole: mass, charge and angular momentum. That is to say, for a black hole, once these three physical quantities are determined, the characteristics of the black hole are uniquely determined. This is the so-called hairless theorem of black holes, or the uniqueness theorem of black holes. But this theorem only limits the classical theory, and does not deny that there may be other quantum charges, so black holes can coexist with large-domain monopoles or cosmic strings with large-domain quantum charges.
The merger of black holes will emit a powerful gravitational wave with a beam of light, and the new black hole will be out of its original position at the core of the galaxy because of recoil. If the speed is high enough, it may even leave the galaxy matrix [1].
classify
Classification method 1:
Supermassive black hole
So far, it can be found in the center of all known galaxies.
It is said that the mass is millions to billions times that of the sun.
Small mass black hole
The mass is 10 to 20 times that of the sun, that is, the core mass left after the supernova explosion is 3 to 15 times that of the sun, which will form a black hole.
Theoretically, when the mass exceeds 40 times that of the sun, a black hole can be formed without a supernova explosion.
Medium black hole
Inference is formed by the merger of small mass black holes, and finally becomes a supermassive black hole.
Whether medium-sized black holes really exist is still in doubt.
Classification method 2: According to the physical characteristics of the black hole itself (mass, charge, angular momentum):
Don't spin a black hole without charge. Its space-time structure was calculated by Schwarzschild in 19 16, and it is called Schwarzschild black hole.
A charged black hole that does not rotate is called an R-N black hole. The spatio-temporal structure was solved by Reissner and Nordstrom in1916-1918.
A rotating uncharged black hole is called a kerr black holes. The spatio-temporal structure was solved by Kerr in 1963.
General black holes are called Kerr-Newman black holes. The spatio-temporal structure was solved by Newman in 1965.
mini black hole
Micro-black hole is a kind of black hole predicted by theory, and there is no evidence to support its existence at present. They were born in the early days of BIGBANG, and their mass is very small. According to Hawking's theory, the smaller the mass of a black hole, the faster it "evaporates". So if there are micro black holes, they must have evaporated by now.
Bermuda, Hongkong and Taiwan Province translate Bermuda (English: Bermuda; Also known as Bermuda; Formerly known as Summers Island, located in the North Atlantic, it is an autonomous overseas territory of Britain. It is located at 32 degrees 14 minutes to 32 degrees 25 minutes north latitude and 64 degrees 38 minutes to 64 degrees 53 minutes west longitude, about 900 kilometers away from North America, about 1, 100 nautical miles northeast of Miami, Florida, on the east coast of the United States, and about 840 nautical miles southeast of Halifax, Nova Scotia, Canada. The nearest landmark is Cape Hatteras, North Carolina, USA, which is about 640 nautical miles (1 0,030 km) northwest. Bermuda is the oldest overseas territory in Britain, one or two centuries before the promulgation of the British Colonial Joint Act 1707 and the establishment of Britain. Since 1945, the United Nations Decolonization Committee has listed it as one of 16 Non-Self-Governing Territories in the world.
"Bermuda" generally refers to a single archipelago, which consists of about 138 islands and many rocks, with a total area of 27.7 square nautical miles (7 1.7 square kilometers), slightly larger than Manhattan Island in the United States (part of new york City, with an area of 22.6 square nautical miles). Seven of the main islands are connected by bridges and causeways, covering an area of 53 square kilometers, and Bermuda (also known as "Great Bermuda") is about 35 square kilometers. Some islands in Bermuda have multiple names (the whole archipelago, together with two official names, was once called "La Garza", "Virginia Ola" and "Devil's Island" in history). Although there are not many landmarks, the phenomenon of renaming local place names is very common; For example, there are two islands called "Long Island", two bays called "Long Bay", and St. George's Town is located in St. George's District on St. George's Island. In addition, Hamilton, the capital of Bermuda, is located in pembroke parish (not Hamilton) on the main island.
Bermuda's economy is prosperous, relying on the financial industry and tourism. It is known as "tax haven" and "enterprise paradise" and is a world-famous offshore financial center. There is a warm tropical climate and beautiful beaches, and it is often proud of the fine pink sand and the blue-green sea.
history
Main entry: Bermuda history
It is believed that Bermuda was first discovered by the Spanish explorer Juan de Bermudez at the beginning of the 6th century, about 1503, but his records only give a rough description. In A.D. 15 1 1 year, the book The Messenger of Babylon written by martyr Peter Dan Guillerat mentioned Bermuda and the Spanish. In the same year, Spain added islands to the chart. Spanish and Portuguese ships use Bermuda as a supply station for fresh meat and water. However, the legend of ghosts makes people afraid to settle in Devil's Island for a long time. Now it is said that it is caused by the harsh sound of Quedao (probably Bermuda petrel) and the continuous wind disaster (which is the case for most early tourists).
Bermuda and Gonzá lez Ferdinando Oviedo speculated on Bermuda around1514-1515, intending to buy pigs on the island as fresh meat futures and sell them to future ships. However, the bad weather in Bermuda prevented them from landing.
A few years later, a Portuguese ship returning from Santo Domingo hit two rocks on the reef. The crew tried their best to rescue and built a new hull with Bermuda cypress in the next four months, returning to the original starting point. It is said that one of the stranded crew members carved the initials "R" and "P" and the year "1543" on the Spanish rock. The original letter may be a symbol of "Rex Portugaline", but it was later misinformed by the Spanish, so that this stone was mistakenly called "Spanish stone".
In the next century, some people stayed at Bermuda's level, but no one settled yet. Britain's first two colonies in Virginia failed, and King James I and King James VI of England resolutely decided to grant the Virginia company a royal franchise. 1609, Admiral Sir George Summers, commander of the company's fleet, led the fleet out of England to help Jamestown colony which was colonized two years ago. Summers had sailed with Sir Francis Drake and Sir Walter Raleigh and accumulated experience. The fleet was damaged in the storm, and the flagship "Ocean Adventure" was wrecked in the waters near Bermuda (as depicted in Bermuda's coat of arms), so the survivors had to live in a new territory. William shakespeare's play The Tempest may have been influenced by William Strachey's account of the shipwreck. The British royal family claimed Bermuda, so they added relevant clauses to the articles of association of the Virginia company. 16 15, Bermuda handed over a new company, Summers Island Company ("Summers Island" is still the official name of the colony), which was composed of the same shareholders. The first British coin in America was minted here.
In 16 10, most of the survivors of ocean exploration were taken to Jamestown by two Bermuda-made ships. John Rolf is one of the survivors. His wife and children are buried in Bermuda. Later, he married pocahontas, the daughter of Chief Powhatan, in Jamestown, and Rolf started the tobacco industry in Virginia alone (logging would be the economic base of the colony). 16 12 With the arrival of plough, the carefully studied Bermuda colonization finally began.
Due to the shortage of land, Bermuda is facing problems brought about by population growth. In the first two colonial centuries, the local population was controlled by stable immigrants. Before the American War of Independence, 1 10,000 Bermudians immigrated, mainly to the southern United States. There, England (later called Great Britain) is replacing Spain as the empire that rules Europe. Before the end of 18, the continuous flow of immigrants has not stopped, and the navigation industry has become the only industry. At that time, at least one third of the people on the island were sailing at sea at any time.
However, in the17th century, Summers Island Company suppressed the shipbuilding industry because they needed Bermudians to farm to earn income. Bermuda cannot be a successful agricultural colony. It is reported that the Bermuda cypress wooden box for transporting tobacco to Britain and the goods from Binet.Alfred are even more valuable. However, the quality and quantity of tobacco produced by Virginia Colony are better than Bermuda. After the collapse of Summers Island Company, Bermudians immediately gave up agriculture and turned to shipbuilding. They replanted the original cypress (Sabina Bermuda, scientific name "Juniperus Bermuda", also known as "Bermuda cypress") on the agricultural land, and the trees quickly grew all over the island. Bermudians made full use of Turks and Caicos Islands, and after deforestation, they started the largest salt trade in the world. Salt trade will become Bermuda's economic pillar in the next century.
Bermuda sailors want to trade, not just supply salt. However, whaling, privateering and commercial trade have developed steadily. The speed and maneuverability of Bermuda dhows are highly valued. At the end of the Battle of Trafalgar, Bermuda's sloop, HMS Pickle, one of the fastest ships in the Royal Navy, even returned to England at full speed with the good news of victory and the death of Admiral Lord Nelson.
After the American War of Independence, the Royal Navy built a large shipyard on the island of Ireland in order to improve the port. In the future, the navy will regard the base as a strategic asset, and later the base will be more beneficial to the United States (see the next paragraph). Bermuda allowed the United States of America's "blockade messenger" spacecraft to stay for a while before sailing south. Now, a small museum preserves the offices used by Confederate troops for espionage.
At the beginning of the 20th century, with the development of modern transportation and communication systems, Bermuda became a popular tourist destination for American, Canadian and British tourists. 1930, the United States promulgated the smoot-Hawley Tariff Act, which interrupted Bermuda's prosperous agricultural export trade to trading partners (mainly supplying fresh vegetables to the United States) and encouraged Bermuda to develop tourism. From an economic point of view, the importance of tourism follows the international financial industry.
politics
The administration of Bermuda is funded by Elizabeth II, and the Governor of Bermuda exercises power on her behalf. The Queen of England appoints the Governor on the advice of the British government. Defence and diplomacy remain the responsibility of Britain, and the authorities must also ensure the effective management of the Bermuda government. Changes to Bermuda's constitution must be approved by Britain.
The Constitution of Bermuda came into force in June 1967 and was revised in June 2003. The head of government is the Prime Minister. The Cabinet is nominated by the Prime Minister and formally appointed by the Governor. The legislature consists of a bicameral parliament. The Senate is the upper house and consists of seven members appointed by the Governor-General on the advice of the Prime Minister and the leader of the opposition. The House of Representatives is the lower house, composed of 36 members elected by the people for a term of five years.
The current Governor is John Vereker, who was appointed on April 1 1 2002. The current prime minister is Ewart Brown, who defeated Alex Scot, the former prime minister of the Labour Party, at the representative meeting in June 5438+ 10, 2006. The Bermuda United Party became an opposition party.
The leadership of the Labor Progressive Party has always supported Bermuda's independence from Britain, but the results of opinion polls are as expected, and the people do not support this move. The party launched a referendum on independence on 1995, but ultimately failed.
military affairs
Bermuda Hamilton Memorial Day parade: Bermuda Army
Bermuda's defense remains the responsibility of the British government. Bermuda used to be the western Atlantic headquarters of the Royal Navy, and the local government used militia to defend the colonies, even until the American Civil War. In the past, the Royal British Sea set up a base, and the shipyard was regularly guarded by soldiers. However, due to excessive military power, it was dissolved in the war of 18 12. /kloc-at the end of 0/9, Bermuda set up a volunteer army to provide reserves for the military garrison.
Bermuda, located near the middle of the North Atlantic, played an important role in the two world wars. The area became a rendezvous point for transatlantic escort ships, as well as a naval and (during World War II) air base. 194 1 year, in exchange for the lease right of Bermuda in 1999, the U.S. military transferred the remaining destroyers of the U.S. navy to the United Kingdom and established naval and air bases until the end of the Cold War. The base covers an area of 5.8 square kilometers (2.25 square miles), and most of the land is reclaimed from the sea.
For many years, Americans used the airport as the front line of aircraft, searching for German and Soviet submarines. Canada once operated a wartime naval base, HMCS Summers Islands, at the former Royal Naval Base in Criminals Bay. At the same time, St. George also set up a radio station at Daniel Point in the western part of the islands.
After World War II, the Royal Navy closed its shipyards and military fortresses. Small supply bases in the United States and bases in the United States and Canada continue to operate within the shipyard. 1 September, 9951day, two bases were closed together with bases in Britain and Canada. Environmental-related problems have dragged down the progress of returning the base land in the United States. It was not until 2002 that the United States officially returned the land to the local government.
Today, Bermuda Army is the only army in Bermuda, a mixed volunteer army formed before the end of 19.
geography
Bermuda is located in the North Atlantic Ocean, about 580 nautical miles (1.074 km) east to southeast from Cape Hatteras, the outer coast of North Carolina, and about 590 nautical miles (1.093 km) southeast of Martha's Vineyard (see map). Bermuda has a coastline of/kloc-0.03 km. Hamilton and St George's Town are two statutory municipalities in Bermuda. Other places are called "villages", such as Flatz Village, Tucker Town and Somerset Village.
It is widely misunderstood that Bermuda is located in the tropics. In fact, Bermuda's subtropical climate is strongly influenced by the nearby Gulf Stream. Bermuda's climate is very humid. Although the temperature seems moderate in summer, the heat index is high. Winter is very warm, and the average daytime temperature in January and February is about 20 C (68 F). Strong winds and heavy rains cause the temperature to drop below freezing point, but the actual temperature rarely drops to10 C (50 F). Rainfall is Bermuda's only source of fresh water, which is collected from roofs and watersheds (or extracted from underground ore bodies) and then stored in storage tanks. Every family usually has at least one reservoir to consolidate the local water supply.
economy
Bermuda has a developed international business and economic system, is an offshore financial center for many foreign companies, and is also a financial export point for insurance and various financial services. Tourism also brings Bermuda considerable income. Bermuda's per capita income is about 50% higher than that of the United States; According to the World Survey published by the US Central Intelligence Agency, Bermuda's GDP in 2004 was US$ 45, which means that the per capita GDP reached US$ 69,900. In other words, Bermuda's per capita GDP is the highest in the world.
Bermuda is regarded as a major offshore financial center, and the government does not levy direct taxes on personal or corporate income. The local tax system depends on import tax, salary tax and consumption tax. Relevant policies have brought advantages to international insurance companies, so Bermuda is regarded as the world reinsurance center. [Source Request] About 400 international companies represented by the Bermuda Association of International Companies (ABIC) are naturally based in Bermuda. Today, more than 65,438+0,500 tax-free companies and international companies are registered in Bermuda.
Tourism is Bermuda's second largest industry, and most tourists come from the United States, Canada and Britain. They will get off the plane at the local Bermuda International Airport.
Bermuda uses the Bermuda dollar, and its currency has been pegged to the US dollar. Within the Islands, US dollar bills and coins can be used interchangeably with Bermuda's currency. Bermuda banknotes bear the head of Elizabeth II.
Human population
The total population of Bermuda is 65,365 (estimated in July 2005), of which 34. 1% is white, 54.8% is black and 6.4% is mixed. At the same time, it also has a small but growing Asian population. Based on the immigrants from Portuguese islands (especially Azores) in the last century, a part of the population kept the Portuguese tradition. This may be traced back to the Madeleine family in 1840s.
In the recent census, racial identity became an issue; [Source Request] The demographic data mentioned in the previous paragraph may be misleading. A few black people on the island have different lineages, especially the European and American indigenous lineages. Portuguese Bermudians are usually regarded as an independent ethnic group, similar to Latin Americans in the United States. Immigrants from Portugal include blacks from Cape Verde and Portuguese who married whites and blacks in Bermuda. Therefore, many islanders who have inherited Portuguese ancestry, traditions and Portuguese names are not counted as 10% or more of the population, but are typically classified as "Portuguese".
Native Americans once again attracted people's attention, especially in St. David, where many residents considered themselves various North American Indians and were sold to Bermuda as slaves during the colonial period of the first century.
In the last century, in addition to large-scale immigrants from Portugal, immigrants from Caribbean countries also emerged.
There are thousands of foreign workers, mainly from Britain, Canada, the West Indies and the United States. They also live in Bermuda and are mainly engaged in industries that require professional skills, such as accounting, finance and insurance. The rest are employed in many industries, including hotels, restaurants, construction, gardening and so on. According to the employment figures released by the government in 2005, of the 38,947 workers, 65,438+065,438+0,223 (29%) are non-Bermudian citizens.
Bermuda's tourist attractions St. David's lighthouse The following are some tourist attractions in Bermuda:
Aquariums, Museums and Zoos in Bermuda [1]
Bermuda Maritime Museum
botanical garden
town hall
Christen jewelry store
Crystal, Fantasy and Leamington Cave
Mount Gibbs lighthouse
Royal Navy Dock (Royal Navy Dock)
St. David lighthouse
St George's
St. Peter's Church
Swizzle hotel
Holidays; holiday
Date holiday remarks
65438+1 October1New Year
Maybe Bermudians will fly homemade kites on Good Friday to celebrate Easter.
Bermuda Day on May 24th originally designated Queen Victoria's birthday morning as Empire Day; Later, it was renamed "Bermuda Day" to formally celebrate the traditions and culture of the islands.
The second Monday in June is the birthday of the Queen of England.
The last Thursday in July or the first Thursday in August, Liberation Day, the first day of the World Cup.
The first Friday in August, the day after the World Cup.
The first Monday in September is Labor Day.
1 1 June11Memorial Day
February 25th Christmas 65438+
65438+Boxing Day on February 26th
culture
Bermuda's culture was deeply influenced by British colonists and inherited most of British traditions and customs. Bermuda is also affected by its proximity to the United States. Most of Bermuda's population is descended from African slaves.
Dance and music are the essence of Bermuda culture, and many dances are influenced by native American immigrants and African slaves. The influence of the Caribbean dominates Bermuda's hobbies.
celebrity
(in alphabetical order of surnames)
Clyde Best, the first English football player (65438+late 1960s-65438+1970s)
Donald henley "Bob" Burns, the Guinness World Record holder with the highest male voice.
G.K. Butterfield, member of the U.S. House of Representatives (D-NC), former judge of the High Court and judge of the National Court of Final Appeal.
Earl cameron, artist.
Diana Deere, artist, mother of Michael and Joel Douglas.
Michael douglas, artist/director
Green Charles Anglim Guibert, Major General, the highest-ranking soldier in Bermuda.
Shaun goater, former Manchester City striker.
Edward Harris, archaeologist and founder of Harris matrix method in archaeological stratigraphy.
Lance Hayward, jazz pianist
Clarence Hill, Olympic boxing bronze medalist.
British artist lena headey.
Heather Nova, musician
Mary Prince was a slave, and her book The History of Mary Prince helped to end slavery in the British Empire.
Arthur Rankin, Jr, producer, director and partner of Rankin/Bass Production Company.
Clarence "Nicky" Sanders, high jump champion of Commonwealth Games.
Gina Swainson, former Miss World (1979—1980)
Edward "Teddy" Tucker, diver and treasure hunter.
Naturalist David B. wingate
Reggae swing/ballroom musician Cory Badez
Bermuda Triangle
Also known as the Devil's Triangle [1] and Death Hell.
It is said that more than 50 ships and more than 20 planes have mysteriously disappeared here. The area is slightly triangular and lies between the south coast of the United States, Bermuda and the Greater Antilles. The unexplained events in this area can be traced back to the middle of19th century. Sometimes the ship is missing for unknown reasons, and sometimes it disappears without a distress signal. A prominent example is that the US Navy auxiliary ship Monocular, loaded with manganese ore, disappeared in March 19 18, and it is still a mystery. 1945, five American bombers took off from Fort Lauderdale Air Force Base in Florida and reported their deaths by radio during flight training. Then the telecommunications gradually weakened and disappeared, and the rescue team disappeared.
Bermuda is a world-famous place, located about 600 kilometers east of North Carolina, USA. The specific geographical location of Bermuda Triangle refers to the triangle formed by connecting Bermuda, Miami (Florida Peninsula, USA) and San Juan (Puerto Rico Island) in the Atlantic Ocean, covering an area of 400,000 square miles. The Baimu Triangle is an archipelago consisting of more than 360 islands. These islands are located in the Atlantic Ocean like rings. Because there is a warm current between Bermuda and the American continent, the climate here is mild, with evergreen seasons and blooming flowers. Bermuda is also known as the most isolated island on earth. Because it is hundreds of miles away from the nearest land, Bermuda is surrounded by a vast ocean, with a panoramic view of blue sky and green water, Bai Ou dancing and flowers overflowing.
However, Bermuda is famous not because of its beautiful island scenery, but because people associate it with the mysterious Bermuda Triangle. According to legend, ships or planes sailing here often disappear mysteriously, and there is no need to find out the reason afterwards, that is, even the wreckage of ships and planes can't be found. So that when the most experienced sailors or navigators pass by here, they have no intention of enjoying the picturesque sea scenery, but they are afraid of encountering bad luck and inexplicably dying in the belly of fish. Now, the Bermuda Triangle has become synonymous with mysterious and incomprehensible disappearance.