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At least 19 recordsLinked to original sources
PubMed2000

John Quincy Adams's rhetorical crusade for astronomy.

Astronomy thrived in Europe during the early nineteenth century, but in the United States a utilitarian mind-set opposed it. John Quincy Adams's oratory in support of American astronomical discovery reached its peak during congressional debate over the Smithsonian Institution (1838-1846). During this debate Adams countered proposals to found a university with plans for an observatory. His addresses to congressional and public audiences about observatories and astronomy were intended to foster interest in the science and encourage the growing astronomical community in America. Although the U.S. Naval Observatory in Washington, D.C., was established before the Smithsonian debate ended, many considered Adams its political father. Adams composed his speeches on astronomy in a systematic manner, following neoclassical principles of rhetoric that he had taught at Harvard University. His speeches both in and outside of Congress show evidence of the rhetorical principles he conscientiously used in the service of astronomy.

Astronomy↗
PubMed2003

Astronomy (communication arising): black holes, fleas and microlithography.

Fresnel lenses allow almost perfect imaging in widely different circumstances, but their focus is perfect only for a single wavelength. Wang et al. have shown how the effective bandpass may be widened for X-ray microscopy by using a compound diffractive/refractive lens near to an absorption edge. A compound lens has also been proposed for high-energy astronomy, working well above all absorption edges. Although the scale is very different, we point out here that the principle is the same. Ever since Galileo constructed an astronomical telescope that he was able to reconfigure to study fleas and gnats, astronomy and microscopy have relied on optics that are closely related, but different in detail.

Animals↗
PubMed2000

Diffusion of astronomy in the ancient world.

Astronomical techniques, calendars and devices were developed independently in many places around the world. However, there was much cross-cultural exchange of technology over the centuries. The cultures of Egypt, Greece, India and China influenced each others' astronomy and each cannot be treated in isolation.

Astronomy↗
PubMed2005

Future perspectives in astronomy and the earth sciences.

This article is an overview of the contributions to the Triennial Issue of Phil. Trans. R. Soc. A published in December, 2005, and also plays the role of a Preface. Devoted to the work of young scientists, the issue covers the fields of astronomy and earth science.

Astronomy↗
PubMed1994

Astronomy and the Extreme Ultraviolet Explorer satellite.

The extreme ultraviolet wave band (100 to 912 angstroms) was thought until recently to be useless to astronomy, primarily because the opacity of the interstellar medium would prevent observations at these wavelengths. However, the interstellar medium has been found to be markedly inhomogeneous in both density and ionization state and the sun is fortunately located in a region of low extreme ultraviolet opacity. The Extreme Ultraviolet Explorer, launched in June 1992, has surveyed the sky in this wave band and has detected a wide variety of astronomical sources at considerable distances, including some extragalactic objects. Studies in the extreme ultraviolet band have already begun to increase our understanding of the contents of the universe.

Astronomy↗
PubMed2001

A prospective health impact assessment of the international astronomy and space exploration centre.

STUDY OBJECTIVES: Assess the potential health impacts of the proposed International Astronomy and Space Exploration Centre on the population of New Wallasey. Contribute to the piloting of health impact assessment methods. DESIGN: Prospective health impact assessment involving brainstorming sessions and individual interviews with key informants and a literature review. SETTING: New Wallasey Single Regeneration Budget 4 area. PARTICIPANTS: Key stakeholders including local residents' groups selected through purposeful snowball sampling. MAIN RESULTS: Recommendations are made that cover issues around: transport and traffic; civic design; security; public safety, employment and training. CONCLUSIONS: Health impact assessment is a useful pragmatic tool for facilitating wide consultation. In particular engaging the local population in the early planning stages of a proposed development, and assisting in highlighting changes to maximise the positive health influences on affected communities.

Astronomical Phenomena↗
PubMed1970

High-energy gamma-ray astronomy.

Gamma-ray astronomy above 10 MeV is difficult from the experimental point of view, but promising data are beginning to appear, as this survey progress report shows.

Journal Article↗
PubMed1970

Momentum conservation and some problems of metagalactic astronomy.

This article explains that bodies of plasma in active galactic nuclei and quasi-stellar objects-"magnetoids"-will attain large momenta because of anisotropy in the generation of relativistic particles and in the synchrotron emission. Magnetoids may therefore be expected to be ejected from the nuclei with high velocities, thus accounting for several puzzling observations in astronomy.

Journal Article↗
PubMed1970

Frequencies for radio astronomy.

At present the scope of research in radio astronomy is limited by the allocation of frequencies, some of which have to be shared with other radio services. When the International Telecommunications Union reconsiders all frequency allocations next year, astronomers are hoping for an improvement.

Journal Article↗
PubMed2002

X-ray astronomy in the new millennium: a summary.

Recent X-ray observations have had a major impact on topics ranging from proto-stars to cosmology. They have also drawn attention to important and general physical processes that currently limit our understanding of thermal and non-thermal X-ray sources. These include unmeasured atomic astrophysics data (wavelengths, oscillator strengths, etc.), basic hydromagnetic processes (e.g. shock structure, reconnection), plasma processes (such as electron-ion equipartition and heat conduction) and radiative transfer (in discs and accretion columns). Progress on these problems will probably come from integrative studies that draw upon observations, throughout the electromagnetic spectrum, of different classes of source. X-ray observations are also giving a new perspective on astronomical subjects, like the nature of galactic nuclei and the evolution of stellar populations. In addition, they are helping us to address central cosmological questions, including the measurement of the matter content of the Universe, understanding its overall luminosity density, describing its chemical evolution and locating the first luminous objects. X-ray astronomy has a healthy future with several international space missions under construction and in development.

Journal Article↗
PubMed2005

Characterization of fluoride fibers for the Optical Hawaiian Array for Nanoradian Astronomy project.

We report on the interferometric characterization of a pair of 300 m long single-mode non-polarization-maintaining fibers designed for the Optical Hawaiian Array for Nanoradian Astronomy ('OHANA) project whose goal is to realize a kilometric near-infrared astronomical array by connecting the large telescopes of the Mauna Kea observatory with single-mode fibers. The fluoride glass fibers are operated in the astronomical K band (2.0-2.4 microm) in which their attenuation is low. We have measured very low differential chromatic dispersion, and the wideband fringe visibility is 0.9 if the two fiber arms have the same temperature. The thermal sensitivity of fibers with respect to their interferometric properties has been studied. The differential chromatic dispersion of the fibers is highly sensitive to the temperature difference. On the contrary, the coherent loss due to mismatch of polarization states is not significantly dependent on the temperature difference. Compensation of thermally induced differential dispersion by use of CaF2 glass plates is demonstrated.

Journal Article↗
PubMed2006

Time dependent neural network models for detecting changes of state in complex processes: applications in earth sciences and astronomy.

A computational intelligence approach is used to explore the problem of detecting internal state changes in time dependent processes; described by heterogeneous, multivariate time series with imprecise data and missing values. Such processes are approximated by collections of time dependent non-linear autoregressive models represented by a special kind of neuro-fuzzy neural network. Grid and high throughput computing model mining procedures based on neuro-fuzzy networks and genetic algorithms, generate: (i) collections of models composed of sets of time lag terms from the time series, and (ii) prediction functions represented by neuro-fuzzy networks. The composition of the models and their prediction capabilities, allows the identification of changes in the internal structure of the process. These changes are associated with the alternation of steady and transient states, zones with abnormal behavior, instability, and other situations. This approach is general, and its sensitivity for detecting subtle changes of state is revealed by simulation experiments. Its potential in the study of complex processes in earth sciences and astrophysics is illustrated with applications using paleoclimate and solar data.

Artificial Intelligence↗
PubMed1995

Laboratory astrophysics and molecular astronomy of pure carbon molecules.

The pure carbon molecules Cn are currently of great experimental and theoretical interest. Our work in this area begins with detection of the SiC molecule, which is isovalent with C2. New infrared electronic transitions of C2 and C3 were discovered by emission spectroscopy of hydrocarbon dicharges. The C3 and C5 molecules were found by infrared vibration-rotation spectroscopy of the prototypical obscured carbon star, IRC+10216. C7 and C9 were searched for in the same source, but not found. The laboratory infrared emission spectrum of C60 was recorded to aid in a search for C60 in extraterrestrial sources.

Astronomy↗
PubMedDate not supplied

Neural networks in astronomy.

In the last decade, the use of neural networks (NN) and of other soft computing methods has begun to spread also in the astronomical community which, due to the required accuracy of the measurements, is usually reluctant to use automatic tools to perform even the most common tasks of data reduction and data mining. The federation of heterogeneous large astronomical databases which is foreseen in the framework of the astrophysical virtual observatory and national virtual observatory projects, is, however, posing unprecedented data mining and visualization problems which will find a rather natural and user friendly answer in artificial intelligence tools based on NNs, fuzzy sets or genetic algorithms. This review is aimed to both astronomers (who often have little knowledge of the methodological background) and computer scientists (who often know little about potentially interesting applications), and therefore will be structured as follows: after giving a short introduction to the subject, we shall summarize the methodological background and focus our attention on some of the most interesting fields of application, namely: object extraction and classification, time series analysis, noise identification, and data mining. Most of the original work described in the paper has been performed in the framework of the AstroNeural collaboration (Napoli-Salerno).

Astronomy↗