Columbia Encyclopedia

Search results

303 results found

erosion

(Encyclopedia)erosion ĭrōˈzhən [key], general term for the processes by which the surface of the earth is constantly being worn away. The principal agents are gravity, running water, near-shore waves, ice (most...

Homo erectus

(Encyclopedia)Homo erectus hōˈmō ērĕkˈtəs [key], extinct hominin living between 1.6 million and 250,000 years ago, possibly as late as c.110,000 years ago. Homo erectus is thought to have evolved in Africa f...

Heaney, Seamus

(Encyclopedia)Heaney, Seamus (Seamus Justin Heaney) shāˈməs, hēˈnē [key], 1939–2013, Irish poet, one of the finest contemporary English poets, b. Londonderry (now Derry), Northern Ireland, grad. Queen's Uni...

Jainism

(Encyclopedia)Jainism jīˈnĭzəm [key] [i.e., the religion of Jina], religious system of India practiced by about 5,000,000 persons. Jainism, Ajivika, and Buddhism arose in the 6th cent. b.c. as protests against ...

morphine

(Encyclopedia)morphine, principal derivative of opium, which is the juice in the unripe seed pods of the opium poppy, Papaver somniferum. It was first isolated from opium in 1803 by the German pharmacist F. W. A. S...

particle detector

(Encyclopedia)CE5 Particle detector—Bubble chamber: A. Pressure drops as piston is raised; B. Charged particles passing through chamber ionize atoms in liquid; C. Bubbles form around atoms and form visible tra...

Tagore, Sir Rabindranath

(Encyclopedia)Tagore, Sir Rabindranath rəbĭnˈdrənät təgôrˈ, täko͝orˈ [key], 1861–1941, Indian author and guru, b. Calcutta (now Kolkata). Tagore came from a wealthy Bengali family. He went abroad in 18...

ultraviolet astronomy

(Encyclopedia)ultraviolet astronomy, study of celestial objects by means of the ultraviolet radiation they emit, in the wavelength range from about 90 to about 350 nanometers. Ultraviolet (UV) line spectrum measure...

Platyhelminthes

(Encyclopedia)CE5 A. Planaria, representative of the phylum Platyhelminthes B. Internal anatomy of Planaria Platyhelminthes plătˌēhĕlmĭnˈthēz [key], phylum containing about 20,000 species of soft-bodied,...

carbon

(Encyclopedia)CE5 The three solid forms of pure carbon: In the diamond crystal each carbon atom is surrounded symmetrically by four other carbons (at each of the four corners of a tetrahedron). In the graphite c...