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non-Euclidean geometry

(Encyclopedia)non-Euclidean geometry, branch of geometry in which the fifth postulate of Euclidean geometry, which allows one and only one line parallel to a given line through a given external point, is replaced b...

median

(Encyclopedia)median. 1 In statistics, a type of average. In a group of numbers as many numbers of the group are larger than the median as are smaller. In the group 4, 5, 6, 9, 13, 14, 19, the median is 9, three nu...

modulation, in communications

(Encyclopedia)CE5 Modulation modulation, in communications, process in which some characteristic of a wave (the carrier wave) is made to vary in accordance with an information-bearing signal wave (the modulatin...

Hermes, in Greek religion and mythology

(Encyclopedia)Hermes, in Greek religion and mythology, son of Zeus and Maia. His functions were many, but he was primarily the messenger of the gods, particularly of Zeus, and conductor of souls to Hades. He was go...

Mass, in Christianity

(Encyclopedia)Mass, religious service of the Roman Catholic Church, which has as its central act the performance of the sacrament of the Eucharist. It is based on the ancient Latin liturgy of the city of Rome, now ...

proportion

(Encyclopedia)proportion, in mathematics, the equality of two ratios. Two pairs of quantities a,b and c,d are in proportion if their ratios a/b and c/d are equal, i.e., if the equation a/b=c/d is true. For example,...

Raleigh

(Encyclopedia)Raleigh rôlˈē, rälˈē [key], city (1990 pop. 207,951), state capital, and seat of Wake co., central N.C.; the site was selected for the capital in 1788, and the city was laid out and inc. 1792. I...

Cygnus

(Encyclopedia)Cygnus sĭgˈnəs [key] [Lat.,=the swan], northern constellation located SE of Draco and NW of Pegasus. It was depicted as a bird by most ancient cultures. It is sometimes called the Northern Cross be...

Cambridge, city, Canada

(Encyclopedia)Cambridge kāmˈbrĭj [key], city, S Ont., Canada, on the Grand River, NW of Hamilton. It was ...

Heron of Alexandria

(Encyclopedia)Heron of Alexandria hērˈŏn [key] or Hero, mathematician and inventor. The dates of his birth and death are unknown; conjecture places them between the 2d cent. b.c. and the 3d cent. a.d. He is beli...