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Fermat, Pierre de

(Encyclopedia)Fermat, Pierre de pyĕr də fĕrmäˈ [key], 1601–65, French mathematician. A magistrate whose avocation was mathematics, Fermat is known as a founder of modern number theory and probability theory....

photoelectric effect

(Encyclopedia)photoelectric effect, emission of electrons by substances, especially metals, when light falls on their surfaces. The effect was discovered by H. R. Hertz in 1887. The failure of the classical theory ...

Euler, Leonhard

(Encyclopedia)Euler, Leonhard lāˈônhärt oiˈlər [key], 1707–83, Swiss mathematician. Born and educated at Basel, where he knew the Bernoullis, he went to St. Petersburg (1727) at the invitation of Catherine ...

atom

(Encyclopedia)CE5 Bohr-Rutherford atom CE5 Probability distribution of the electron in the hydrogen atom: A. Ground state B. Highly excited state atom [Gr.,=uncuttable (indivisible)], basic unit of matte...

quaestor

(Encyclopedia)quaestor kwĕsˈtôr [key], Roman magistrate, with responsibility for the treasury; in early times a quaestor also had judicial powers. At first there were two quaestors. Sulla named 20, and Caesar se...

Weierstrass, Karl Wilhelm Theodor

(Encyclopedia)Weierstrass, Karl Wilhelm Theodor kärl vĭlˈhĕlm tāˈōdōr vīˈərshträs [key], 1815–97, German mathematician. From 1864 he was professor of mathematics at the Univ. of Berlin. His developmen...

Wiener, Norbert

(Encyclopedia)Wiener, Norbert, 1894–1964, American mathematician, educator, and founder of the field of cybernetics, b. Columbia, Mo., grad. Tufts College, 1909, Ph.D. Harvard, 1913. In 1920 he joined the faculty...

Hilbert, David

(Encyclopedia)Hilbert, David, 1862–1943, German mathematician, professor at Königsberg (1886–95) and Göttingen (1895–1930), b. Königsberg, Germany. His proof of the theorum of invariants (1890) supplanted ...

statistics

(Encyclopedia)statistics, science of collecting and classifying a group of facts according to their relative number and determining certain values that represent characteristics of the group. The most familiar stat...

Penrose, Sir Roger

(Encyclopedia)Penrose, Sir Roger, 1931–, British mathematical physicist, Ph.D. Cambridge, 1958. He taught and conducted research at a number of British and American colleges and universities before becoming a pro...