NUCLEAR WEAPON

The mushroom cloud of the atom bomb dropped on Nagasaki, Japan in 1945 rose some 18 kilometers (11 miles) above the bomb's hypocenter.

A nuclear weapon (sometimes called a nuclear bomb) is a type of weapon of mass destruction and an explosive device that derives its destructive force from nuclear reactions (either fission or a combination of fission and fusion). Both reactions release vast quantities of energy from relatively small amounts of matter; a modern thermonuclear weapon weighing little more than a thousand kilograms can produce an explosion comparable to the detonation of more than a billion kilograms of conventional high explosive. Even small nuclear devices with yields equivalent to several thousand tons of TNT can devastate a city. Nuclear weapons are considered weapons of mass destruction, and their use and control has been a major aspect of international policy since their debut in Nagasaki and Hiroshima.

In the history of warfare, only two nuclear weapons have been detonated offensively, both during the closing days of World War II. The first was detonated on the morning of August 6, 1945, when the United States dropped a uranium gun-type device code-named "Little Boy" on the Japanese city of Hiroshima. The second was detonated three days later on August 9, 1945, when the United States dropped a plutonium implosion-type device code-named "Fat Man" on the city of Nagasaki, Japan. These bombings resulted in the immediate deaths of around 120,000 people (mostly civilians) from injuries sustained from the explosion and acute radiation sickness, and even more deaths from long-term effects of (ionizing) radiation. The use of these weapons was and remains controversial. (See atomic bombings of Hiroshima and Nagasaki for a full discussion.)

Since the Hiroshima and Nagasaki bombings, nuclear weapons have been detonated on over two thousand occasions for testing purposes and demonstration purposes. The only countries known to have detonated nuclear weapons – and that acknowledge possessing such weapons – are (chronologically) the United States, the Soviet Union (succeeded as a nuclear power by Russia), the United Kingdom, France, the People's Republic of China, India, Pakistan, and North Korea. Israel is also widely believed to possess nuclear weapons, though it does not acknowledge having them. For more information on these states' nuclear programs, as well as other states that formerly possessed nuclear weapons or are suspected of seeking nuclear weapons, see List of states with nuclear weapons.

Nuclear strategy

Main article: Nuclear warfare

The United States' Peacekeeper missile was a MIRVed delivery system. Each missile could contain up to ten nuclear warheads (shown in red), each of which could be aimed at a different target. These were developed to make missile defense very difficult for an enemy country

Nuclear warfare strategy is a way for either fighting or avoiding a nuclear war. The policy of trying to ward off a potential attack by a nuclear weapon from another country by threatening nuclear retaliation is known as the strategy of nuclear deterrence. The goal in deterrence is to always maintain a second strike status (the ability of a country to respond to a nuclear attack with one of its own) and potentially to strive for first strike status (the ability to completely destroy an enemy's nuclear forces before they could retaliate). During the Cold War, policy and military theorists in nuclear-enabled countries worked out models of what sorts of policies could prevent one from ever being attacked by a nuclear weapon.

Different forms of nuclear weapons delivery (see below) allow for different types of nuclear strategy, primarily by making it difficult to defend against them and difficult to launch a pre-emptive strike against them. Sometimes this has meant keeping the weapon locations hidden, such as putting it on submarines or train cars whose locations are very hard for an enemy to track, and other times this means burying them in hardened bunkers. Other responses have included attempts to make it seem likely that the country could survive a nuclear attack, by using missile defense (to destroy the missiles before they land) or by means of civil defense (using early warning systems to evacuate citizens to a safe area before an attack). Note that weapons which are designed to threaten large populations or to generally deter attacks are known as strategic weapons. Weapons which are designed to actually be used on a battlefield in military situations are known as tactical weapons.

There are critics of the very idea of nuclear strategy for waging nuclear war who have suggested that a nuclear war between two nuclear powers would result in mutual annihilation. From this point of view, the significance of nuclear weapons is purely to deter war because any nuclear war would immediately escalate out of mutual distrust and fear, resulting in mutually assured destruction. This threat of national, if not global, destruction has been a strong motivation for anti-nuclear weapons activism.

Critics from the peace movement and within the military establishment have questioned the usefulness of such weapons in the current military climate. The use of (or threat of use of) such weapons would generally be contrary to the rules of international law applicable in armed conflict, according to an advisory opinion issued by the International Court of Justice in 1996.

Perhaps the most controversial idea in nuclear strategy is that nuclear proliferation would be desirable. This view argues that, unlike conventional weapons, nuclear weapons successfully deter all-out war between states, as they did during the Cold War between the U.S. and the Soviet Union. Political scientist Kenneth Waltz is the most prominent advocate of this argument.

It has been claimed that the threat of potentially suicidal terrorists possessing nuclear weapons (a form of nuclear terrorism) complicates the decision process. Mutually assured destruction may not be effective against an enemy who expects to die in a confrontation, as they may feel they will be rewarded in a religious afterlife as martyrs and would not therefore be deterred by a sense of self-preservation. Further, if the initial act is from rogue groups of individuals instead of a nation, there is no fixed nation or fixed military targets to retaliate against. It has been argued, especially after the September 11, 2001 attacks, that this complication is the sign of the next age of nuclear strategy, distinct from the relative stability of the Cold War.

Barack Obama

Barack Obama President-elect of the United States Taking office January 20, 2009 Vice President Joe Biden (elect) Succeeding George W. Bush United States Senator from Illinois In office January 4, 2005 – November 16, 2008 Preceded by Peter Fitzgerald Succeeded by TBD Member of the Illinois Senate from the 13th district In office January 8, 1997 – November 4, 2004 Preceded by Alice Palmer Succeeded by Kwame Raoul Born August 4, 1961 (1961-08-04) (age 47) Honolulu, Hawaii, U.S.A. Birth name Barack Hussein Obama II Political party Democratic Party Spouse Michelle Obama (m. 1992) Children Malia Ann (b. 1998) Sasha (b. 2001) Residence Kenwood, Chicago, Illinois Alma mater Columbia University Harvard Law School Profession Attorney Politician Religion United Church of Christ Signature Website Office of the President-Elect More detailed articles about Barack Obama ———————————— Early life and career · (Family · Memoir) Illinois Senate career U.S. Senate career Presidential primaries · Obama–Biden 2008 Policy positions · Public image

Barack Hussein Obama II (pronounced /bəˈrɑːk hʊˈseɪn oʊˈbɑːmə/; born August 4, 1961) is the President-elect of the United States and the first African American to be elected President of the United States. Obama was the junior United States Senator from Illinois from 2005 until he resigned on November 16, 2008, following his election to the Presidency.

He is a graduate of Columbia University and Harvard Law School, where he was president of the Harvard Law Review. Obama worked as a community organizer and practiced as a civil rights attorney before serving three terms in the Illinois Senate from 1997 to 2004. He also taught constitutional law at the University of Chicago Law School from 1992 to 2004. Following an unsuccessful bid for a seat in the U.S. House of Representatives in 2000, he announced his campaign for the U.S. Senate in January 2003, won a primary victory in March 2004, and was elected to the Senate in November 2004. Obama delivered the keynote address at the Democratic National Convention in July 2004.

As a member of the Democratic minority in the 109th Congress, he helped create legislation to control conventional weapons and to promote greater public accountability in the use of federal funds. He also made official trips to Eastern Europe, the Middle East, and Africa. During the 110th Congress, he helped create legislation regarding lobbying and electoral fraud, climate change, nuclear terrorism, and care for returned U.S. military personnel.

Early life and career

Barack Obama was born at the Kapi'olani Medical Center for Women & Children in Honolulu, Hawaii,to Barack Obama, Sr., a Luo from Nyang’oma Kogelo, Nyanza Province, Kenya, and Ann Dunham, a white American from Wichita, Kansas of mainly English, Irish and smaller amounts of German descent.His parents met in 1960 while attending the University of Hawaii at Manoa, where his father was a foreign student.The couple married February 2, 1961; they separated when Obama was two years old and subsequently divorced in 1964.Obama's father returned to Kenya and saw his son only once more before dying in an automobile accident in 1982.

After her divorce, Dunham married Lolo Soetoro, and the family moved to Soetoro's home country of Indonesia in 1967, where Obama attended local schools, such as Asisi, in Jakarta until he was ten years old. He then returned to Honolulu to live with his maternal grandparents, Madelyn and Stanley Dunham, while attending Punahou School from the fifth grade in 1971 until his graduation from high school in 1979. Obama's mother returned to Hawaii in 1972 for several years, and then in 1977 went back to Indonesia, where she worked as an anthropological field worker. She stayed there most of the rest of her life, returning to Hawaii in 1994. She died of ovarian cancer in 1995.

Right-to-left: Barack Obama and half-sister Maya Soetoro-Ng, with their mother Ann Dunham and grandfather Stanley Dunham, in Hawaii (early 1970s)

As an adult Obama admitted that he used marijuana, cocaine, and alcohol when in high school, which he described as his greatest moral failure at the 2008 Civil Forum on the Presidency.

Following high school, Obama moved to Los Angeles, where he studied at Occidental College for two years.He then transferred to Columbia University in New York City, where he majored in political science with a specialization in international relations.Obama graduated with a B.A. from Columbia in 1983, then at the start of the following year worked for a year at the Business International Corporation and then at the New York Public Interest Research Group.

After four years in New York City, Obama moved to Chicago, where he was hired as director of the Developing Communities Project (DCP), a church-based community organization originally comprising eight Catholic parishes in Greater Roseland (Roseland, West Pullman, and Riverdale) on Chicago's far South Side, and worked there for three years from June 1985 to May 1988. During his three years as the DCP's director, its staff grew from one to thirteen and its annual budget grew from $70,000 to $400,000, with accomplishments including helping set up a job training program, a college preparatory tutoring program, and a tenants' rights organization in Altgeld Gardens.Obama also worked as a consultant and instructor for the Gamaliel Foundation, a community organizing institute. In mid-1988, he traveled for the first time to Europe for three weeks and then for five weeks in Kenya, where he met many of his Kenyan relatives for the first time.

Obama entered Harvard Law School in late 1988. At the end of his first year, he was selected, based on his grades and a writing competition, as an editor of the Harvard Law Review.In February 1990, in his second year, he was elected president of the Law Review, a full-time volunteer position functioning as editor-in-chief and supervising the Law Review's staff of eighty editors. Obama's election as the first black president of the Law Review was widely reported and followed by several long, detailed profiles.During his summers, he returned to Chicago where he worked as a summer associate at the law firms of Sidley & Austin in 1989 and Hopkins & Sutter in 1990. After graduating with a Juris Doctor (J.D.) magna cum laude from Harvard in 1991, he returned to Chicago.

The publicity from his election as the first black president of the Harvard Law Review led to a publishing contract and advance for a book about race relations.In an effort to recruit him to their faculty, the University of Chicago Law School provided Obama with a fellowship and an office to work on his book.He originally planned to finish the book in one year, but it took much longer as the book evolved into a personal memoir. In order to work without interruptions, Obama and his wife, Michelle, traveled to Bali where he wrote for several months. The manuscript was finally published in mid-1995 as Dreams from My Father.

Obama directed Illinois' Project Vote from April to October 1992, a voter registration drive with a staff of ten and seven hundred volunteers; it achieved its goal of registering 150,000 of 400,000 unregistered African Americans in the state, and led to Crain's Chicago Business naming Obama to its 1993 list of "40 under Forty" powers to be.

Obama served for twelve years as a professor at the University of Chicago Law School, teaching constitutional law. He was first classified as a Lecturer from 1992 to 1996, and then as a Senior Lecturer from 1996 to 2004.He also joined Davis, Miner, Barnhill & Galland, a twelve-attorney law firm specializing in civil rights litigation and neighborhood economic development, where he was an associate for three years from 1993 to 1996, then of counsel from 1996 to 2004, with his law license becoming inactive in 2002.

Obama was a founding member of the board of directors of Public Allies in 1992, resigning before his wife, Michelle, became the founding executive director of Public Allies Chicago in early 1993. He served from 1994 to 2002 on the board of directors of the Woods Fund of Chicago, which in 1985 had been the first foundation to fund the Developing Communities Project, and also from 1994 to 2002 on the board of directors of The Joyce Foundation. Obama served on the board of directors of the Chicago Annenberg Challenge from 1995 to 2002, as founding president and chairman of the board of directors from 1995 to 1999. He also served on the board of directors of the Chicago Lawyers' Committee for Civil Rights Under Law, the Center for Neighborhood Technology, and the Lugenia Burns Hope Center.

Robot

ASIMO, a humanoid robot manufactured by Honda

A Pick and Place robot in a factory

A robot is a mechanical or virtual artificial agent. In practice, it is usually an electro-mechanical system which, by its appearance or movements, conveys a sense that it has intent or agency of its own. The word robot can refer to both physical robots and virtual software agents, but the latter are usually referred to as bots. There is no consensus on which machines qualify as robots, but there is general agreement among experts and the public that robots tend to do some or all of the following: move around, operate a mechanical arm, sense and manipulate their environment, and exhibit intelligent behavior, especially behavior which mimics humans or animals.

Some examples of factory robots:

Car production: Over the last three decades automobile factories have become dominated by robots. A typical factory contains hundreds of industrial robots working on fully automated production lines, with one robot for every ten human workers. On an automated production line, a vehicle chassis on a conveyor is welded, glued, painted and finally assembled at a sequence of robot stations.

• Packaging: Industrial robots are also used extensively for palletizing and packaging of manufactured goods, for example for rapidly taking drink cartons from the end of a conveyor belt and placing them into boxes, or for loading and unloading machining centers.
• Electronics: Mass-produced printed circuit boards (PCBs) are almost exclusively manufactured by pick-and-place robots, typically with SCARA manipulators, which remove tiny electronic components from strips or trays, and place them on to PCBs with great accuracy. Such robots can place hundreds of thousands of components per hour, far out-performing a human in speed, accuracy, and reliability.
• Automated guided vehicles (AGVs): Mobile robots, following markers or wires in the floor, or using vision or lasers, are used to transport goods around large facilities, such as warehouses, container ports, or hospitals. Early AGV-style robots were limited to tasks that could be accurately defined and had to be performed the same way every time. Very little feedback or intelligence was required, and the robots needed only the most basic exteroceptors (sensors). However, newer AGVs such as the Speci-Minder, ADAM, Tug and PatrolBot Gofer navigate by recognizing natural features. 3D scanners or other means of sensing the environment in two or three dimensions help to eliminate cumulative errors in dead-reckoning calculations of the AGV's current position. Some AGVs can create maps of their environment and use those maps to navigate in real time by simultaneous localization and mapping (SLAM). They are able to operate in complex environments and perform non-repetitive and non-sequential tasks such as transporting photomasks in a semiconductor lab, specimens in hospitals and goods in warehouses.

Dirty, dangerous, dull or inaccessible tasks

A U.S. Marine Corps technician prepares to deploy a device that will detonate a buried improvised explosive device near Camp Fallujah, Iraq

There are many jobs which humans would rather leave to robots. The job may be boring, such as domestic cleaning, or dangerous, such as exploring inside a volcano. Other jobs are physically inaccessible, such as exploring another planet, cleaning the inside of a long pipe, or performing laparoscopic surgery.

• Domestic robots: As prices fall and robots become smarter and more autonomous, robots are increasingly being seen in the home where they are taking on simple but unwanted jobs, such as floor cleaning and lawn mowing.

• Telerobots: When a human cannot be present on site to perform a job because it is dangerous, far away, or inaccessible, teleoperated robots, or telerobots are used. Rather than following a predetermined sequence of movements, a telerobot is controlled from a distance by a human operator. The robot may be in another room or another country, or may be on a very different scale to the operator. For instance, a laparoscopic surgery robot allows the surgeon to work inside a human patient on a relatively small scale compared to open surgery, significantly shortening recovery time. Several authors have been using a device called the Longpen to sign books remotely.

• Military robots: Teleoperated robot aircraft, like the Predator Unmanned Aerial Vehicle, are increasingly being used by the military. These pilotless drones can search terrain and fire on targets.Hundreds of robots such as iRobot's Packbot and the Foster-Miller TALON are being used in Iraq and Afghanistan by the U.S. military to defuse roadside bombs or Improvised Explosive Devices (IEDs) in an activity known as explosive ordnance disposal (EOD).

Home automation for the elderly and disabled: The average age of the population is increasing in many countries, especially in Japan, meaning that there are more elderly people to care for and fewer people available to care for them.

Stories of artificial helpers and companions and attempts to create them have a long history, but fully autonomous machines only appeared in the 20th century. The first digitally operated and programmable robot, the Unimate, was installed in 1961 to lift hot pieces of metal from a die casting machine and stack them. Today, commercial and industrial robots are in widespread use performing jobs more cheaply or with greater accuracy and reliability than humans. They are also employed for jobs which are too dirty, dangerous or dull to be suitable for humans. Robots are widely used in manufacturing, assembly and packing, transport, earth and space exploration, surgery, weaponry, laboratory research, and mass production of consumer and industrial goods.

People have a generally positive perception of the robots they actually encounter. Domestic robots for cleaning and maintenance are increasingly common in and around homes. There is anxiety, however, over the economic impact of automation and the threat of robotic weaponry, anxiety which is not helped by the many villainous, intelligent, acrobatic robots in popular entertainment. Compared with their fictional counterparts, real robots are still benign, dim-witted and clumsy.

Search Engine Optimization

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A typical search engine results page

Search engine optimization (SEO) is the process of improving the volume and quality of traffic to a web site from search engines via "natural" ("organic" or "algorithmic") search results. Usually, the earlier a site is presented in the search results, or the higher it "ranks," the more searchers will visit that site. SEO can also target different kinds of search, including image search, local search, and industry-specific vertical search engines.

As an Internet marketing strategy, SEO considers how search engines work and what people search for. Optimizing a website primarily involves editing its content and HTML coding to both increase its relevance to specific keywords and to remove barriers to the indexing activities of search engines. Sometimes a site's structure (the relationships between its content) must be altered too. Because of this it is, from a client's perspective, always better to incorporate Search Engine Optimization when a website is being developed than to try and retroactively apply it.

The acronym "SEO" can also refer to "search engine optimizers," a term adopted by an industry of consultants who carry out optimization projects on behalf of clients, and by employees who perform SEO services in-house. Search engine optimizers may offer SEO as a stand-alone service or as a part of a broader marketing campaign. Because effective SEO may require changes to the HTML source code of a site, SEO tactics may be incorporated into web site development and design. The term "search engine friendly" may be used to describe web site designs, menus, content management systems and shopping carts that are easy to optimize.

Another class of techniques, known as black hat SEO or Spamdexing, use methods such as link farms and keyword stuffing that degrade both the relevance of search results and the user-experience of search engines. Search engines look for sites that employ these techniques in order to remove them from their indices.