cosmic abundance
3.The article discusses Some main observed facts of the model of big-bang cosmology by the releuant theories of modern physics,for example Hubble law cosmic microwave background radiation helium abundance and so on,make an attempt on preliminary des- cribing for observed facts to theories for the model of big-bang cosmology.
4.The observational cosmology and its recent progress are reviewed, including observational methods, Hubble constant, Hubble time, dark matter, dark energy, cosmic background radiation, large-scale structure, element abundance and active galactic nucleus, neutrino, gamma-ray bursts etc. . In addition, the problems and challenges are discussed as well as the perspective to the observational cosmology.
5.To the great scale of the universe age, 187 Re- 187 Os isotopic pair, which have very long half life, was used as a cosmic nuclear clock of cosmochronometr. It is a typical relationship between modern astronomy and nuclear physics. The neutral isotope abundance ratio of 187 Re over daughter nucleus 187 Os in common growth mineral can be used as the clock to measure the time.
7.The big bang model, which states that almost 14 billion years ago the universe started expanding from a state of extremely high density and temperature, is able to explain galaxy motions, the abundance of hydrogen and helium, and the properties of the cosmic microwave background (CMB), the remnant heat from the expanding and cooling gas.
