smart weapon, missile or steerable bomb equipped with a laser, television, or satellite guidance system. Smart weapons, which use guidance systems that rely on external assistance, are distinguished from brilliant weapons, which are totally self-guided. In the case of a smart bomb with a laser guidance system, an aircraft pilot aims a laser beam at the target, a computer keeps the beam locked on the target, and the bomb has a sensor programmed to find the reflection of the laser's light. A guidance computer adjusts the path of the bomb after it is released, using movable fins to steer. A television guidance system uses a television camera in the nose of the weapon to lock onto the image of the target identified by the pilot. Satellite-guided bombs have guidance computers that use signals from navigation satellites to confirm that they are on target; the tail fins are adjusted to control the bomb's course as it falls. Cruise missiles also utilize information from navigation satellites to maintain a proper course during flight. Extensions of smart-weapon technology are off-road mines that can "listen" for moving vehicles and attack them, "thinking" antipersonnel mines that are activated or deactivated automatically after a set period of time, and missile and artillery fire targeted by space-based intelligence-gathering satellites.

smart card, small device that resembles a credit card but contains an embedded microprocessor to store and process information. Magnetic-stripe cards, which store a very small amount of information (most typically used to identify the owner) and have no processing capability of their own, can be thought of as primitive smart cards. A true smart card contains 80 or more times as much memory, and the microprocessor allows information to be read and updated every time the card is used. Contact cards, which must be swiped through card readers, are less prone to misalignment and being misread but tend to wear out from the contact; contactless cards, which are read by holding the card in front of a low-powered laser, can be used in mobile applications, such as collecting tolls from cards as drivers pass through toll booths without stopping.

Developed in 1973 by the Frenchman Roland Marino, the smart card was not introduced commercially until 1981, when the French state telephone system adopted it as an integral part of its phonecard network. This led to widespread use in France and then Germany, where patients have health records stored on the cards. A large-scale pilot program involving 40,000 people and 1,000 retail merchants and using smart cards as stored value, or electronic purse, cards—in which the card contains a stored monetary value that is decremented with each purchase and incremented by loading additional value onto the card through automated teller machines (ATMs) or public telephones—was initiated in Swindon, England, in 1995. Smaller pilots were held in Canberra, Australia; in the Atlanta, Ga., metropolitan area in conjunction with the 1996 Summer Olympic Games; in New York City; and in Guelph, Ontario. All of these achieved only limited customer acceptance and were shut down by 1998. Another major problem is that these and other smart card ventures do not have a common technology; global acceptability will come only after international standards are adopted.

As memory capacity, computing power, and data encryption capabilities of the microprocessor increase, smart cards are envisioned as replacing such commonplace items as cash, airline and theater tickets, credit and debit cards, toll tokens, medical records, and keys. Suggested government use of a single smart card to replace driver's licenses, passports, social security and welfare documentation, and the like has caused a debate concerning the civil liberty implications of such uses of the smart card.

Smart, Christopher, 1722-71, English poet. A graduate of Cambridge, he lived in London writing poems, editing a humorous magazine, and producing plays. His one great poem, Song to David (1763), an inspirational piece containing superb imagery, was written while he was confined in an asylum for a religious mania. He is also known for his idiosyncratic and often anthologized paean to his cat, Jeoffry, from the surviving fragments of his Jubilate Agno, which was also written during his confinement but not published in a definitive edition until 1954.

Bomb with a guidance system that directs its path toward a target. It is steered by fins or wings on the bomb that move in response to guidance commands. Guidance systems may be electro-optical, laser, infrared, or inertial. Electro-optical systems send pictures of the area so that the bomb can be guided onto the target. Laser-guided bombs follow the reflections of a laser beam trained onto the target by an aircraft or a spotter on the ground. Infrared guidance responds to radiation generated by warm areas of the target. Inertial navigation is based on inputting coordinates derived from radar systems or from Global Positioning System satellites into the bomb's gyroscopes. Smart bombs, initially used in the Vietnam War, offer far greater accuracy than traditional gravity, or “dumb,” bombs.

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