Astronomy definitions

Nevertheless the heat capacity of a carbon resistor was not so low as that of crystalline materials used later. More important, carbon resistors had an excess noise which limited the bolometer performance. In 1961, Low [61] proposed a bolometer which used a heavily doped Ge thermometer with much improved characteristics. This type of bolometer was rapidly applied to infrared astronomy as well also to laboratory spectroscopy. A further step in the development of bolometers came with improvements in the absorber. In the early superconducting bolometer built by Andrews et al. (1942) [62], the absorber was a blackened metal foil glued to the 7A thermometer. Low s original bolometer [61] was coated with black paint and Coron et al. [63] used a metal foil as substrate for the black-painted absorber. A definite improvement is due to J. Clarke, G. I. Hoffer, P. L. Richards [64] who used a thin low heat capacity dielectric substrate for the metal foil and used a bismuth film absorber instead of the black paint. 

There were critics who thought that chemistry could never be more than a combination of laboratory practice, which they viewed as a kind of cookery, and classification, which they saw as the essence of natural history, including botany and zoology. Those same critics regarded natural history as unscientific, lacking the rigor of mathematical physics or astronomy. Chemistry was indeed far from Newtonian physics. We have already seen the failure of attempts to assimilate chemistry to Newton s program. But to dismiss chemistry for this reason was to adopt too narrow a definition of science and to undervalue the role of classification in the scientific enterprise as a whole. Natural historians have to classify what they observe or collect so do chemists. 

By Vitruvius s definition, an architect needs to be the master of everything or jack of all trades. It might have been possible then for one person to master the multiple disciplines of art, science, and engineering such as literature, mathematics, history, philosophy, music, medicine, and astronomy, as we assume those disciplines during those days were at a rather superficial level. But with advancement of science and technology, it is not possible for one person to master the multiple disciplines of art, science and engineering. It should be noted that there are more scientists alive today that all of the scientists ever lived in the history of mankind ... 

For the benefit of those readers who are familiar with the paradigms of modern science, but find the arguments and methodologies of cosmology totally bewildering, it is necessary to provide a historical survey of how two pursuits, so disparate, could develop from their common root of astronomy. Naked-eye astronomy never was powerful enough to establish a definitive model of the cosmos and to eliminate fanciful notions based on personal conviction or dogmatic prescription. 

With COMPTEL on the Gamma-ray Observatory, the concept has definitely proven its unique potential for MeV gamma-ray astronomy (Schonfelder et al. 1993). 

For the macroscopic sciences of physics and astronomy, it was the age of Scientific Revolution but for chemists dealing with the contortions of unseen molecules, fundamental principles remained obscure. There was a feeling that the underlying theory for their investigations—that matter was composed of some number of elements and that these elements were present in all matter— was not providing answers, but chemists did not have the information needed for a new definition. By the end of the l600s however, they would be closing in. 

Abstract. This paper describes the status of NASA s Space Infrared Telescope Facility (SIRTF) program. SIRTF will be a cryogenicaily cooled observatory for infrared astronomy from space and is planned for launch early in t next decade. It will be the first cryogenic space observatory to make extensive use of the powerfrd infrared detector array tednology discussed at this conference. We summarise a newly developed SIRTF mission concept and show how the availability of detector arrays has shaped the scientific rationale for SIRTF, and how the arrays themsdves have become part of the definition of the SIRTF misaon. 

It is useful to envision a perfect array as a benchmark for how far we have progressed. My personal definition is an array with roughly 10 pixds, each, of which has detective quantum efficiency (DQE) > 50% and works at the background limit in any foreseeable application. Evm more ambitious definitions cotdd be formulated and more ambitious arrays would produce advances in many types of measurement. Howeva, from watchii my colleagues in optical astronomy, I have noted that many considerations besides performance become important once my perfect array becomes available. 

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