989-after c. 1079 Spanish Moor mathematician and astronomer who made important contributions to geometrical mathematics. Born in Córdoba, Spain, Ibn Muadh was evidently in Cairo from 1012 to 1017 and moved to Jaén in Spain where ...

Abu Bakr Muhammad ibn Tufayl (ca. 1110-1185) was a Spanish Moslem philosopher and physician, author of the celebrated allegorical tale "Hayy Ibn Yaqzan." Known to medieval Christian scholastics as Abubacer (from Abu Bakr), Ibn Tufayl was b...

Ibn ṬUfayl(D. 580 Ah/1185 Ce) Abū Bakr Muḥammad ibn ʿAbd al-Malik ibn Ṭufayl, the Islamic philosopher, was known to medieval Scholastics as Abubacer. Few details are known about the life of Ibn Ṭufa...

Ibn Zaddik, Joseph Ben Jacob(D. 1149) Joseph ben Jacob ibn Zaddik, like other Jewish philosophers of a Neoplatonic cast, such as Yehuda Halevi and Abraham ibn Ezra, was a poet as well as a philosopher and legist. Very few of his poems survi...

The roots of the shrub Tabernanthe iboga first aroused pharmacological interest in 1864 when a French naval surgeon brought some back from Gabon, West Africa. The root was eaten by various Gabonese tribes as part of initiation ceremonies o...

908-946 Arab mathematician and grandson of Thabit ibn Qurra (836-901). Ibrahim's most significant work involved the quadrature of the parabola, and he is credited with improving on the ideas of Archimedes (c. 287-212 B.C.) with his ...

This is the official classi-fication system of the World Health Organization (WHO). As a general system for the classification of diseases, injuries, causes of death, and related health problems, the ICD is used throughout the world as a c...

any geologic period during which thick ice sheets cover vast areas of land. Such periods of large-scale glaciation may last several million years and drastically reshape surface features of entire continents. A number of major ice ages hav...

No sport grew as phenomenally during the last two decades of the twentieth century as figure skating. Having been a favorite sport among women, its popularity was bolstered by Olympic gold medal winners Peggy Fleming (1968), Janet Lynn (19...

The ice cream cone is a familiar feature of the American leisure landscape, carrying with it associations of fairgrounds, ice cream parlors, drugstore soda fountains, and all-American kids (and adults) enjoying a sunshine treat. Since its ...

Ice skating, in one form or another, has existed for thousands of years. Evidence suggests that as long ago as 1000 B.C. Scandinavians were fashioning crude blades from the shank or rib bones of elk, oxen, and reindeer and strapping them o...

floating mass of freshwater ice that has broken from the seaward end of either a glacier or an ice shelf. Icebergs are found in the oceans surrounding Antarctica, in the seas of the Arctic and sub-Arctic, in Arctic fjords, and in lakes fed...

island country located in the North Atlantic Ocean. Lying on the constantly active geologic border between North America and Europe, Iceland is a land of vivid contrasts of climate, geography, and culture. Sparkling glaciers, such as Vatna...

(1883–1959), prime minister of Japan. Hatoyama Ichiro was born in Tokyo, the first son of Dr. Hatoyama Kazuo, a legal scholar, lawyer, and (later) leading politician, and Hatoyama Haruko, a pioneer in women's education. After...

Ichthyology is the science of animals that deals with fish. This field includes the study of fish growth, development, structure, characteristics, classification, geographical distribution, and the relationship of fish to their environment...

In computer terminology, an icon is a small picture that represents an object, a program, or some other specific item that is relevant to the user. Icons are a principal tool of graphical user interfaces. On a Web page, an icon is typicall...

the science of identification, description, classification, and interpretation of symbols, themes, and subject matter in the visual arts. The term can also refer to the artist's use of this imagery in a particular work. The earliest iconog...

A pioneering neurophysiologist and supporter of allowing women to pursue studies in the sciences despite a prevailing gender bias, Dr. Ida Henrietta Hyde (1857-1945) was the first woman to earn a Ph.D. in science at Heidelberg University i...

An actress, director, and screenwriter of considerable reputation, Ida Lupino was born into a distinguished British theater family. After a less than satisfactory start in Hollywood as a blonde ingenue type, Lupino broke through with a str...

Ideas The word "idea" is a transliteration of a Greek word of which the root meaning is "see." In classical Greek it never lost the possible meaning "visual aspect"; thus Plato writes of a person a...

The relationship between three state variables, absolute pressure (P), volume (V), and absolute temperature (T), that is deduced from kinetic theory and characterizes an ideal gas is called the ideal gas law, PV = nRT, where P is absolute ...

The concept of identical particles becomes important in the study of quantum mechanics. In a classical description from atomic physics--for instance, the one proposed by Ernest Rutherford--an atom resembles a miniature solar system. Proton...

An identifier is a sequence of one or more alphanumeric characters that uniquely names or characterizes the contents, nature, or properties of: (1) a data element, such as the name of an file, account, procedure, variable, or other such en...

Identity The word is is multiply ambiguous. When it can be expanded to read "is the same thing as," or "is identical with," or (in numerical contexts) "is equal to," it expresses the relation of id...

IDOLATRY. The word idolatry is formed from two Greek words, eidōlon, "image," and latreia, "adoration." Etymologically, idolatry means "adoration of images." Authors have given idolatry and ...