Columbia Encyclopedia

(Encyclopedia) heat, nonmechanical energy in transit, associated with differences in temperature between a system and its surroundings or between parts of the same system. The study of heat and its relationship ...

(Encyclopedia) stock exchange, organized market for the trading of stocks and bonds (see bond; stock). Such markets were originally open to all, but at present only members of the owning association may buy and sell...

(Encyclopedia)  CE5 The asteroid belt lies between the orbits of Mars and Jupiter. Gaps where no asteroids are found are called Kirkwood gaps. The Trojan asteroids share Jupiter's orbit with the planet. asteroid,...

(Encyclopedia) mass extinction, the extinction of a large percentage of the earth's species, opening ecological niches for other species to fill. There have been at least ten such events. The five greatest were thos...

(Encyclopedia) Missouri, river, c.2,565 mi (4,130 km) long (including its Jefferson-Beaverhead-Red Rock headstream), the longest river of the United States and the principal tributary of the Mississippi River. The l...

(Encyclopedia) Germanic religion, pre-Christian religious practices among the tribes of Western Europe, Germany, and Scandinavia. The main sources for our knowledge are the Germania of Tacitus and the Elder Edda and...

(Encyclopedia) continent, largest unit of landmasses on the earth. The continents include Eurasia (conventionally regarded as two continents, Europe and Asia), Africa, North America, South America, Australia, and An...

(Encyclopedia) forest, a dense growth of trees, together with other plants, covering a large area of land. The science concerned with the study, preservation, and management of forests is forestry. A forest is an ec...

(Encyclopedia) migration, of people, geographical movements of individuals or groups for the purpose of permanently resettling. Normal internal migration has been characterized by a population shift from rural t...

(Encyclopedia)  CE5 Atmosphere atmosphere [Gr.,=sphere of air], the mixture of gases surrounding a celestial body with sufficient gravity to maintain it. Although some details about the atmospheres of other plane...