Biographical

Alhough there were occasional reports of new or guest stars in all cultures through the ages, medeval western astronomers looked at the "fixed" stars as eternal and invariable entities. This view was blown up in a dramatic show by Tycho's supernova ("Stella Nova", "New Star") in 1572. Soon after, some more variable stars were discovered, including the first periodic one, Mira (the periodicity of which was only discovered considerably later in 1638, by Holwarda; up to this time the four known variables had all been classified as "Stellae Novae", although none of them was actually a nova).

The founding of the Jacques Maritain Center in 1957 consolidated the great French Catholic philosopher's association with the University of Notre Dame. For some years previously, Maritain had been coming to Notre Dame to lecture and stay for short periods of time. Father Theodore M. Hesburgh, the president of the University, friend and admirer of Maritain, wanted to make the relationship permanent. The Center was founded to ensure that the thought and spirit of Jacques Maritain would remain at Notre Dame long after those present on the happy occasion of its founding were gone.

Christian Huygens was born at the Hague on April 14, 1629, and died in the same town on July 8, 1695. He generally wrote his name as Hugens, but I follow the usual custom in spelling it as above: it is also sometimes written as Huyghens. His life was uneventful, and there is little more to record in it than a statement of his various memoirs and researches.

Uppsala University was founded in 1477 and is the oldest of the scandinavian universities. Preserved lecture notes from the 1480's show that lectures in astronomy were given at the philosophical faculty. There is no certain evidence of a professorship in astronomy until 1593 when the university was reerected after a period of decline following the Lutheran reformation.

Apart from the Vikings, who without doubt navigated and kept track of time by means of the stars, the first important Danish astronomer was Peder Nightingale. In 1274 he observed the sunlatitude from Roskilde where he was a canon, and based on these observations he made tables showing the length of day and nights. Later he published a widespread calender in Paris. There is some indication in the sources, that he didn't believe in the relation between astrology and astronomy which was the common belief at that time.
In 1417 were "Speculum Planetarum" published by Johannes Simones de Selandia a book about the movements of the planets, very little is known of Johannes.

With its numerous cultivated varieties, the sweet orange (Citrus sinensis Osbeck) constitutes one of the world's most popular and recognizable fruit crops. Sweet oranges are citrus fruits (Citrus spp.), which are regarded as high sources of vitamin C (ascorbic acid) and other fruit acids. These fruits are hesperidiums, because of their fleshiness and separable rind. Physically, citrus fruits consist of forty to fifty percent juice, twenty to forty percent rind and twenty to thirty-five percent pulp and seeds. Chemically, they contain eighty-six to ninety-two percent water, five to eight percent sugars and one to two percent pectin with lesser amounts of acids, protein, essential oils and minerals (Janick et. al. 1981). Citrus fruits grow on small evergreen trees, many of which depend on root mycorrhizae (Janick et. al. 1981). Most of these C3 plants are cultivated as scions on rootstocks. All Citrus species have a diploid chromosome number of eighteen and are interfertile.

In 1822 Gideon Mantell, a doctor from Lewes, East Sussex, described a fossil tooth which his wife had found by the side of the road in Cuckfield, West Sussex. This tooth was the first dinosaur fossil in the world ever to be found and identified. For the very first time people realised creatures as large as dinosaurs had once existed

MendelWeb is an educational resource for teachers and students interested in the origins of classical genetics, introductory data analysis, elementary plant science, and the history and literature of science. Constructed around Gregor Mendel's 1865 paper "Versuche über Pflanzen-Hybriden" and a revised version of the English translation by C.T. Druery and William Bateson, "Experiments in Plant Hybridization", MendelWeb is offered as a public sourcebook and collaborative environment compatible with a variety of guided and independent studies. For some background and an early description of the project, you may want to read MendelWeb: An electronic science/math/history resource for the WWW, a short paper prepared for the 2nd International World Wide Web Conference.

Available here are accounts of the lives and works of seventeenth and eighteenth century mathematicians (and some other scientists), adapted from A Short Account of the History of Mathematics by W. W. Rouse Ball (4th Edition, 1908).

The ordering of the mathematicians and scientists below is approximately chronological. A separate index is provided which lists these people in alphabetical order.

The Disability History Project is a community history project and we welcome your participation. This is an opportunity for disabled people to reclaim our history and determine how we want to define ourselves and our struggles. People with disabilities have an exciting and rich history that should be shared with the world. Please email us about anything that you would like to see become part of the Disability Social History Project, including your disabled heroes, important events in disability history, and resources.