James MacCullagh

James MacCullagh (* 1809 in Landahaussy, † October 24, 1847 in Dublin) was an Irish mathematician and physicist.

Life

MacCullagh was born 1809 in Landahaussy, near Strabane, County Tyrone, and attended from 1824 to 1829 Trinity College (Dublin), which was at this time, William Rowan Hamilton. In 1832 he won a scholarship and became a Fellow of mathematical assistant and then professor of mathematics at Trinity College ( from 1843 Professor of " Natural Philosophy ", that theoretical physics ). In 1843 he became a member of the Royal Society, after he received the Copley Medal him a year earlier. MacCullagh died in Dublin by suicide, after he had two years earlier, in a letter to Hamilton about a lessening of his mathematical abilities. His collected works were published in 1880 in Dublin.

Work

Most of the time he spent with research on optics in connection with the theory of diffraction and refraction, in which he treated Fresnel's wave theory with geometric methods. In two important papers on crystal optics him but William Rowan Hamilton and Franz Ernst Neumann came here before, which led to priority disputes. In 1839 he was in a working theory of the ether as an elastic medium of light propagation, which although well the reflection and refraction in crystals reproduced, but was rejected by his contemporaries, since they seemed to imply a rotation of the medium with respect to absolute space. Until 40 years later, George Francis FitzGerald pointed out that MacCullogh with its 1839 presented equations published in 1864 Maxwell equations anticipated in the case under consideration. Best known to his contemporaries, however, were his contributions to geometry (on surfaces of the second order 1843).

MacCullagh corresponded with John Herschel and Charles Babbage, who wrote that MacCullagh was an excellent friend of his, with whom he discussed the benefits and impact of the Analytical Engine.