eCosmology

Astrophysics - Apparent Magnitude of stars in a close binary system? Astrophysics - Apparent Magnitude of stars in a close binary system 1. The problem statement, all variables and given/known data 2 solar type stars are in a close binary system. Each indivual star has an apparent brightness of m = 10 mag. Determine the apparent magnitudes of the combined system of the 2 stars assuming they cannot be resolved as individual objects. Determine the minimum brightness for this eclipsing binary when 100%, 75%, 50% and 25% of the stellar survace are covered during the eclipse. 2. Relevant equations m1 - m2 = -2.5 log(f1/f2) 3. The attempt at a solution m1 - m2 = -2.5 log (f1/f2) 10-10 = -2.5log(f1/f2) f1/f2 =1 f1=f2 m1+2 - m2 = -2.5 log (f1+f2 \ f2) f1 = f2 m1+2 - m2 = -2.5 log (2f1 \ f1) m1+2 - m2 = -2.5 log 2 m1+2 = -2.5log2 + 5 mag m1+2=4.247425011 m1+2 = 4.25 mag Then I'm not sure how to continue from here - any help would be most appreciated!

Jesus said, you shall know the tree by its fruit.? Science, including the Theory of Evolution enabled great strides in human development. Evolutionary theory has been put to practical use in several areas (Futuyma 1995; Bull and Wichman 2001). For example: * Bioinformatics, a multi-billion-dollar industry, consists largely of the comparison of genetic sequences. Descent with modification is one of its most basic assumptions. * Diseases and pests evolve resistance to the drugs and pesticides we use against them. Evolutionary theory is used in the field of resistance management in both medicine and agriculture (Bull and Wichman 2001). * Evolutionary theory is used to manage fisheries for greater yields (Conover and Munch 2002). * Artificial selection has been used since prehistory, but it has become much more efficient with the addition of quantitative trait locus mapping. * Knowledge of the evolution of parasite virulence in human populations can help guide public health policy (Galvani 2003). * Sex allocation theory, based on evolution theory, was used to predict conditions under which the highly endangered kakapo bird would produce more female offspring, which retrieved it from the brink of extinction (Sutherland 2002). Phylogenetic analysis, which uses the evolutionary principle of common descent, has proven its usefulness: * Tracing genes of known function and comparing how they are related to unknown genes helps one to predict unknown gene function, which is foundational for drug discovery (Branca 2002; Eisen and Wu 2002; Searls 2003). * Phylogenetic analysis is a standard part of epidemiology, since it allows the identification of disease reservoirs and sometimes the tracking of step-by-step transmission of disease. For example, phylogenetic analysis confirmed that a Florida dentist was infecting his patients with HIV, that HIV-1 and HIV-2 were transmitted to humans from chimpanzees and mangabey monkeys in the twentieth century, and, when polio was being eradicated from the Americas, that new cases were not coming from hidden reservoirs (Bull and Wichman 2001). It was used in 2002 to help convict a man of intentionally infecting someone with HIV (Vogel 1998). The same principle can be used to trace the source of bioweapons (Cummings and Relman 2002). * Phylogenetic analysis to track the diversity of a pathogen can be used to select an appropriate vaccine for a particular region (Gaschen et al. 2002). * Ribotyping is a technique for identifying an organism or at least finding its closest known relative by mapping its ribosomal RNA onto the tree of life. It can be used even when the organisms cannot be cultured or recognized by other methods. Ribotyping and other genotyping methods have been used to find previously unknown infectious agents of human disease (Bull and Wichman 2001; Relman 1999). * Phylogenetic analysis helps in determining protein folds, since proteins diverging from a common ancestor tend to conserve their folds (Benner 2001). Directed evolution allows the "breeding" of molecules or molecular pathways to create or enhance products, including: * enzymes (Arnold 2001) * pigments (Arnold 2001) * antibiotics * flavors * biopolymers * bacterial strains to decompose hazardous materials. The evolutionary principles of natural selection, variation, and recombination are the basis for genetic algorithms, an engineering technique that has many practical applications, including aerospace engineering, architecture, astrophysics, data mining, drug discovery and design, electrical engineering, finance, geophysics, materials engineering, military strategy, pattern recognition, robotics, scheduling, and systems engineering (Marczyk 2004). Clearly this shows that the Theory of Evolution yields good fruit, and therefore following Jesus' teachings, the Theory of Evolution itself is good. Why do fundamentalists not obey Jesus and accept the Theory of Evolution?

Creationists, which of the following do you feel is the number one agenda of scientists who endorse evolution? 1. Tying together biology by explaining similarities and differences between organisms, fossils, biogeography, drug resistance, extreme features such as the peacock's tail, relative virulence of parasites, etc. 2. The multi-billion dollar Bioinformatics industry which consists largely of the comparison of genetic sequences. 3. Resistance management in both medicine and agriculture. 4. Improved management of fisheries to obtain greater yields. 5. The study of parasite virulence in human populations which helps guide public health policy. 6. Sex allocation theory (based on evolution theory) to help bring endangered species like the Kakapo bird back from the brink of extinction by determining how to produce more female offspring. 7. Phylogenetic analysis, which is a foundation for drug discovery and helps us track the step-by-step transmission of disease. 8. Directed evolution, which allows the "breeding" of molecules or molecular pathways to create or enhance products, including: enzymes, pigments, antibiotics, flavors, biopolymers, and bacterial strains to decompose hazardous materials. Directed evolution can also be used to study the folding and function of natural enzymes 9. Genetic algorithms, an engineering technique that has many practical applications, including aerospace engineering, architecture, astrophysics, data mining, drug discovery and design, electrical engineering, finance, geophysics, materials engineering, military strategy, pattern recognition, robotics, scheduling, and systems engineering. 10. To convince all Christians that their god did not create humans from a handful of dust.