Columbia Encyclopedia

Search results

500 results found

Poynting, John Henry

(Encyclopedia)Poynting, John Henry, 1852–1914, British physicist. He was educated at Liverpool and Cambridge and was professor of physics at the Univ. of Birmingham for most of his life. He is best known for the ...

anticyclone

(Encyclopedia)anticyclone, region of high atmospheric pressure; anticyclones are commonly referred to as “highs.” The pressure gradient, or change between the core of the anticyclone and its surroundings, combi...

prostate gland

(Encyclopedia)prostate gland, gland that is part of the male reproductive system. It is an organ about the size of a chestnut and consists of glandular and muscular tissue. It is situated below the neck of the blad...

Embargo Act of 1807

(Encyclopedia)Embargo Act of 1807, passed Dec. 22, 1807, by the U.S. Congress in answer to the British orders in council restricting neutral shipping and to Napoleon's restrictive Continental System. The U.S. merch...

depth charge

(Encyclopedia)depth charge, explosive device used against submarines and other underwater targets, either rolled into the water from rails on the stern of a ship or propelled from depth charge throwers. The charge ...

detonator

(Encyclopedia)detonator dĕˈtənāˌtər [key], type of explosive that reacts with great rapidity and is used to set off other, more inert explosives. Fulminate of mercury mixed with potassium chlorate is a common...

Heymans, Corneille

(Encyclopedia)Heymans, Corneille kôrnāˈyə hīˈmäns [key], 1892–1968, Belgian physiologist. His contributions to the physiology of circulation include a study of the sensory mechanism through which arterial ...

biofeedback

(Encyclopedia)biofeedback, method for learning to increase one's ability to control biological responses, such as blood pressure, muscle tension, and heart rate. Sophisticated instruments are often used to measure ...

Saha, Meghnad

(Encyclopedia)Saha, Meghnad māgnädˈ säˈhä [key], 1893–1956, Indian physicist. He was a professor at Allahabad Univ. from 1923 to 1938 and a professor and physics department head at Calcutta Univ. from 1938....

diagnosis

(Encyclopedia)diagnosis, determination of the nature of a disease or ailment. A clinical diagnosis is based on the medical history and physical examination of the patient: it may be confirmed with X-Rays, CAT Scans...