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Bell, Alexander Graham

(Encyclopedia)Bell, Alexander Graham, 1847–1922, American scientist, inventor of the telephone, b. Edinburgh, Scotland, educated at the Univ. of Edinburgh and University College, London; son of Alexander Melville...

solar energy

(Encyclopedia)solar energy, any form of energy radiated by the sun, including light, radio waves, and X rays, although the term usually refers to the visible light of the sun. Solar energy is needed by green plants...

Qur'an

(Encyclopedia)Qur'an or Koran kōrănˈ, –ränˈ [key] [Arab.,=reading, recitation], the sacred book of Islam. Revealed by God to the Prophet Muhammad in separate revelations over the major portion of the Prophet...

Saint Lawrence Seaway

(Encyclopedia)Saint Lawrence Seaway, international waterway, 2,342 mi (3,769 km) long, consisting of a system of canals, dams, and locks in the St. Lawrence River and connecting channels between the Great Lakes; op...

spintronics

(Encyclopedia)spintronics, spin electronics, or magnetoelectronics, science and technology that harnesses the spin state of electrons in addition to the electrical charge state to store data or perform calculation...

signaling

(Encyclopedia)signaling, transmission of information by visible, audible, or other detectable means. Since prehistoric times humans have sought and employed ever more effective means of communicating over distance....

capital punishment

(Encyclopedia)capital punishment, imposition of a penalty of death by the state. Since the 1970s almost all capital sentences in the United States have been imposed for homicide. There has been intense debate reg...

submarine

(Encyclopedia)submarine, naval craft capable of operating for an extended period of time underwater. Submarines are almost always warships, although a few are used for scientific, business, or other purposes (see a...

apartment house

(Encyclopedia)apartment house, building having three or more dwelling units. Numerous early examples of this form of dwelling have been found in remains of Roman and medieval cities and in the 17th-cent. Pueblo vil...

arrhythmia

(Encyclopedia)arrhythmia ārĭᵺˈmēə [key], disturbance in the rate or rhythm of the heartbeat. Various arrhythmias can be symptoms of serious heart disorders; however, they are usually of no medical significan...