Columbia Encyclopedia

(Encyclopedia) Day, Dorothy, 1897–1980, American journalist and social activist, b. New York City. After studying at the Univ. of Illinois (1914–16), where she joined the Socialist party, she returned to New Yor...

(Encyclopedia) tropical year, time between successive vernal equinoxes; 365 days, 5 hr, 48 min, 46 sec of mean solar time (see solar time). The tropical year is the basis of the year used in the Gregorian calendar. ...

(Encyclopedia) Day, Clarence Shepard, 1874–1935, American essayist, b. New York City, grad. Yale, 1896. His biographical sketches of his parents, God and My Father (1932), Life with Father (1935), and Life with Mo...

(Encyclopedia) anomalistic year ənŏmˌəlĭsˈtĭk [key], time required for the earth to go from the perihelion point once around the sun and back to the perihelion point. It is 365 days, 6 hr, 13 min, 53.0 sec of...

(Encyclopedia) sidereal year, time required for the earth to complete an orbit of the sun relative to the stars. The sidereal year is 365 days, 6 hr, 9 min, 9.5 sec of mean solar time (see solar time). It is 20 min ...

(Encyclopedia) Veterans' Day, holiday formerly observed in the United States as Armistice Day in commemoration of the signing of the Armistice ending World War I. Nov. 11 officially became Veterans' Day on May 24, 1...

(Encyclopedia) International Geophysical Year (IGY), 18-month period from July, 1957, through Dec., 1958, during a period of maximum sunspot activity, designated for cooperative study of the solar-terrestrial enviro...

(Encyclopedia) Earth Day, Apr. 22, a day to celebrate the environment. The first Earth Day was organized in 1970 to promote the ideas of ecology, encourage respect for life on earth, and highlight growing concern ov...

(Encyclopedia) degree-day, a unit of measure used to estimate the fuel and power requirements in heating and cooling a building; it is equal to a difference of 1 degree between the outdoor daily average temperature ...

(Encyclopedia) holiday [altered from holy day], day set aside for the commemoration of an important event. Holidays are often accompanied by public ceremonies, such as parades and carnivals, and by religious observa...