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energy, sources of

(Encyclopedia)energy, sources of, origins of the power used for transportation, for heat and light in dwelling and working areas, and for the manufacture of goods of all kinds, among other applications. The develop...

drone

(Encyclopedia)drone or remotely piloted vehicle, a pilotless craft guided by remote control. Aircraft, ships, and land vehicles can be designed or outfitted as drones. Underwater vessels—both piloted and pilotles...

modem

(Encyclopedia)modem [modulator/demodulator], an external device or internal electronic circuitry used to transmit and receive digital data over a communications line normally used for analog signals. A modem attach...

road

(Encyclopedia)road, strip of land used for transportation. The history of roads has been related to the centralizing of populations in powerful cities, which the roads have served for military purposes and for trad...

tsunami

(Encyclopedia)tsunami tso͝onäˈmē [key], series of catastrophic ocean waves generated by submarine movements, which may be caused by earthquakes, volcanic eruptions, landslides beneath the ocean, or an asteroid ...

butterfly

(Encyclopedia)butterfly, any of a large group of insects found throughout most of the world; with the moths, they comprise the order Lepidoptera. There are about 12 families of butterflies. Most adult moths and but...

migration of animals

(Encyclopedia)migration of animals, movements of animals in large numbers from one place to another. In modern usage the term is usually restricted to regular, periodic movements of populations away from and back t...

space science

(Encyclopedia)space science, body of scientific knowledge as it relates to space exploration; it is sometimes also called astronautics. Space science draws on the conventional sciences of physics, chemistry, biolog...

land use

(Encyclopedia)land use, exploitation of land for agricultural, industrial, residential, recreational, or other purposes. Because the United States historically has a laissez-faire attitude toward land use, the land...

turnpike

(Encyclopedia)turnpike, road paid for partly or wholly by fees collected from travelers at tollgates. It derives its name from the hinged bar that prevented passage through such a gate until the toll was paid. See ...