Astronomical practice

Astronomy is infinitely subdivided. There are as many astronomies as colours in the visible and invisible spectra, and even more if we include the study of non-electromagnetic signals like neutrinos and gravitational waves. 

Astronomical data is archived and released in the form of images (maps and outlines) and spectra (distribution of photons as a function of their energy). Duly classified, these constitute a huge database. The problem then is to give physical and astrophysical meaning to these cosmic archives, via an interpretation within the framework of the most relevant physical theory. 

The quality and insight of the theoretical interpretation or model must relate to the accuracy of the observations. The secret of astrophysics resides in the 

---

What Is Interferometry (1.3) Interferometry deals with the physical phenomena which result from the superposition of electromagnetic (e.m.) waves. Practically, interferometry is used throughout the electromagnetic spectrum astronomers use predominantly the spectral regime from radio to the near UV. Essential to interferometry is that the radiation emerges from a single source and travels along different paths to the point where it is detected. The spatio-temporal coherence characteristics of the radiation is studied with the interferometer to obtain information about the physical nature of the source. 

If this happens, then the components are said to be matched to the beam (see Fig. 2). The requirements of Eq. (30) can be converted into surface quality requirements, concerning chiefly the surface figure and the homogeneity of the reflection factor. In terms familiar to astronomers, the surface figure requirements for gw detectors are in the (A/100, A/200) range on about 1000 cm surfaces (see Fig. 2).This requirement is in practice very difficult to fulfill, and new mirror manufacturing methods had to be developed (see Ch. 19). 

Considers what the author calls practical hermetica, astronomical, alchemical, and magical literature dealing with practical matters, not connected with the "Corpus Hermeticum"... 

There are only a few really basic schemes which have been used to determine fluorescent lifetimes. The minor variations upon these, however, are truly astronomical. We therefore consider only a few representatives from this vast group. It should be pointed out, however, that only some of the instruments considered in this section are truly practical and have been consistently applied to rare earths. Some are novel and illustrate new and ingenious ways that might prove useful for future work. 

Furthermore, the neo-Darwinian hypothesis says that the insulin gene had been duplicated long ago and that the left-over copy has mutated into a relaxin.6 Once the astronomical number of mutations had led to an active relaxin any further mutation that would hit the invariant positions would have killed or severely handicapped the owner of that hormone, and therefore all constant residues are important. My colleague Dr. Erika Biillesbach has developed an ingenious as well as practical way to synthesize relaxin and insulin for our NIH-funded research.3 These derivatives allowed us to experimentally test some of the postulated mechanisms in the Darwinian model of molecular evolution. 

In 1924, the Russian astronomer Numerov (transliterating his own name as Noumerov), published a paper [421] in which he described some improvements in approximations to derivatives, to help with numerical simulations of the movement of bodies in the solar system. His device has been adapted to the solution of pdes, and was introduced to electrochemistry by Bieniasz in 2003 [108]. The method described by Bieniasz is also called the Douglas equation in some texts such as that of Smith [514], where a rather clear description of the method is found. With the help of the Numerov method, it is possible to attain fourth order accuracy in the spatial second derivative, while using only the usual three points. The first paper by Bieniasz on this method treated equally spaced grids, and was followed by another on unequally spaced grids [107], The method makes it practical to use higher-order time derivative approximations without the complications of, say, the (6,5)-point scheme described above, which makes the solution of the system of equations a little complicated (and computer time consuming). 

Charles Piazzi Smyth was not an occultist but Professor of Practical Astronomy at the University of Edinburgh and Astronomer Royal for Scotland. His Our Inheritance in the Great Pyramid (1864), reached its fifth edition in 1890. 

Probably the chief characteristic of true savants—whether they be archaeologists, mathematicians, chemists, astronomers, or physicists—, is that they do not endeavor to apply their work in practice. 

Homology-based protein structure prediction methods are the methods of choice, in practice. The reason is that the number of protein folds occurring in nature is much smaller than the number of protein sequences, as nature conserves successful structural architectures much more than the exact protein sequence. On the sequence level much variation is found in orthol-ogous proteins from different organisms with same structure and function. Thus, if we are looking for a fold of a natural protein, it is much more economical to test the limited set of folds realized by nature than to search in an astronomically large space of potential protein structures. 

---