We provide information about the history of Federal efforts devoted to public health, preserve and interpret the history of PHS, and promote historically-oriented activities across the U.S. Department of Health and Human Services, in partnership with the History Office of the Food and Drug Administration and the National Institutes of Health Historical Office.
Built in 1967 by RCA, the David Sarnoff Library contains a museum, an archive, a library, and this website. Besides Mr. Sarnoff's papers and memorabilia, the Library's holdings include 25,000 photographs and thousands of notebooks, reports, publications, and artifacts related to the histories of RCA Laboratories and RCA. At this site you will find exhibits, timelines, galleries, links, and references.
The David Sarnoff Library is named for the pioneering President of RCA (Radio Corporation of America), a division of General Electric and one of the earliest industry leaders in radio and television technology. The site contains timelines of Sarnoff, RCA, radio, television, and several other topics. A large number of images are also available on a range of subjects such as early television performers and equipment. The site is still under construction, but the final edition will include memoirs of former engineers and workers at the RCA labs.
An historical compendium of the people, departments, schools, research centres and affiliated organisations that make up the Faculty of Medicine, Dentistry and Health Sciences at the University of Melbourne, with references to archival materials and a bibliography of historical published literature.
Last year saw two interesting events in the world of double stars, both of them connected with an astronomer's old friend in the Big Dipper. While the early history of double star astronomy had to be completely rewritten after an examination of 17th century Italian manuscripts, its future at the beginning of the next millennium was briefly unveiled by the amazing precision of a new astrometric instrument, which will soon eliminate the difference between spectroscopic and visual binaries.
Until quite recently, I though that the first published HR diagram was constructed by Ejnar Hertzsprung for the stars of the Pleiades. Already in 1908, when Hertzsprung (then still an amateur astronomer with training in photochemistry) visited Karl Schwarzschild at Göttingen, he brought with him a working version with photographic magnitudes plotted against effective wavelengths. To determine the latter quantity, nowadays replaced by spectral type or color index, Hertzsprung attached a coarse diffraction grating before the objective so that an ordinary stellar image on the photographic plate was accompanied by a very short first-order spectrum on either side. The separation of the most intense parts of these spectra then directly translated into the effective wavelength of the star's light. However, this first Hertzsprung attempt to visualize the relation between luminosities and colors of stars suffered from a systematic error due to influence of the secondary spectrum of the objective. It was not until 1911, when the satisfactory version of the diagram was presented (Publ. Astrophys. Observ. Potsdam 22, 1, 1911) together with a color-magnitude diagram for another winter cluster, the Hyades.
X-ray Astronomy at Goddard:
Early History
From 1965 to 1972 there were over a dozen balloon-borne experiments (mostly from New Mexico), including the first such to take place from Australia (1966), one in which hard X-ray emission was discovered (albeit with crude angular resolution) from a region towards the galactic center whose centroid is located among subsequently identified sources GX1+4, GX3+1, and GX5-1. A balloon-borne experiment in 1968 was based on the multi-anode multi-layer xenon gas proportional chamber that had recently been developed in our lab and represented the first use of such a high performance instrument for X-ray astronomy.
Mathematics represents a high level of abstraction attained by the human mind. In India, mathematics has its roots in Vedic literature which is nearly 4000 years old. Between 1000 B.C. and 1000 A.D. various treatises on mathematics were authored by Indian mathematicians in which were set forth for the first time, the concept of zero, the techniques of algebra and algorithm, square root and cube root.
This web site is an online gateway to the extraordinary library resources of Harvard University and serves as an important research tool for Harvard's current students, faculty, staff, and researchers who hold Harvard IDs and PINs. The site also provides practical information on each of the more than 90 libraries that form the Harvard system. Visitors and guests should consult the Library's Frequently Asked Questions before navigating the sit
This paper deals with the English rejection of the Gregorian calendar in 1583, seeking to set this episode in its cultural, political and intellectual context. It concentrates particularly upon the work of John Dee, whose treatise of advice to the queen on the calendar reform is almost the only one of his major writings which has not (as far as I am aware) been studied in any depth in published writings.
From around 3000 BC onwards, astronomy in its most primitive form had developed. The sun, moon and changing seasons would have already been well studied. Perhaps the chief difference in thinking at that time was that the earth was flat. People genuinely believed that if you went far enough you would fall off the edge.
