Irish Gaelic poet and historian. He wrote his Forus Feasa ar Eirinn/ A Basis for Knowledge about Ireland about 1630. In it he refutes other commentators on Ireland, particularly the Elizabethan chroniclers of the preceding generation, and produces the first attempt at a complete compendium of history and legendary material. He also wrote poetry, in densely wrought assonantal metres.
He was born in Burges, County Tipperary. Educated at Bordeaux and Salamanca, he returned to Ireland as a Catholic priest in 1610.
English clown. A member of several Elizabethan theatre companies, he joined the Chamberlain's Men in 1594, acting in the roles of Dogberry in Shakespeare Much Ado About Nothing and Peter in Romeo and Juliet. He published Kempe's Nine Days' Wonder ( 1600), an account of his nine-day dance to Norwich from London.
German mathematician and astronomer. He formulated what are now called Kepler's laws of planetary motion: (1) the orbit of each planet is an ellipse with the Sun at one of the foci; (2) the radius vector of each planet sweeps out equal areas in equal times; (3) the squares of the periods of the planets are proportional to the cubes of their mean distances from the Sun. Kepler's laws are the basis of our understanding of the Solar System, and such scientists as Isaac Newton built on his ideas.
Kepler was one of the first advocates of Sun-centred cosmology, as put forward by Copernicus. Unlike Copernicus and Galileo, Kepler rejected the Greek and medieval belief that orbits must be circular in order to maintain the fabric of the cosmos in a state of perfection.
early work Kepler also produced a calendar of predictions for the year 1595 which proved uncanny in its accuracy. In 1596, he published his Prodromus Dissertationum Cosmographicarum seu Mysterium Cosmographicum in which he demonstrated that the five Platonic solids (the only five regular polyhedrons) could be fitted alternately inside a series of spheres to form a 'nest'. The nest described quite accurately (within 5%) the distances of the planets from the Sun. Kepler regarded this discovery as a divine inspiration that revealed the secret of the Universe. Written in accordance with Copernican theories, it brought Kepler to the attention of all European astronomers.
In 1601 Kepler was bequeathed all of Tycho Brahe's data on planetary motion. He had already made a bet that, given Tycho's unfinished tables, he could find an accurate planetary orbit within a week. It was five years before Kepler obtained his first planetary orbit, that of Mars. His analysis of these data led to the discovery of his three laws. In 1604 his attention was diverted from the planets by his observation of the appearance of a new star, ' Kepler's nova'. Kepler had observed the first supernova visible since the one discovered by Brahe in 1572.
Kepler's laws Kepler's first two laws of planetary motion were published in Astronomia Nova ( 1609). The first law stated that planets travel in elliptical rather than circular, or epicyclic, orbits and that the Sun occupies one of the two foci of the ellipses. The second law established the Sun as the main force governing the orbits of the planets. It stated that the line joining the Sun and a planet traverses equal areas of space in equal periods of time, so that the planets move more quickly when they are nearer the Sun. He also suggested that the Sun itself rotates, a theory that was confirmed using Galileo's observations of sunspots, and he postulated that this established some sort of 'magnetic' interaction between the planets and the Sun, driving them in orbit. This idea, although incorrect, was an important precursor of Newton's gravitational theory.
Kepler's third law was published in De Harmonices Mundi. It described in precise mathematical language the link between the distances of the planets from the