由荷马史诗看希腊黑暗时代法律思想

荷马史诗这一彪炳千古的伟大史诗系列,是对半传说半史实的特洛伊战争的诗意叙述。史诗所反映的古希腊黑暗时代的法律思想,主要包括正义观和政体观两方面。荷马史诗中一切正义都是宙斯的意志,包括分配的正义和纠正的正义。其中分配的正义并非绝对平等,具有差异性的分配才能做到各得其所,而纠正的正义更多通过私人血亲复仇来体现,既符合复仇者自身的正义观,也体现了众神的正义观。荷马史诗中政体观主要通过描述其所处时代的政治演变来体现。从特洛伊到黑暗时代,史诗描述与历史事实的差异,体现了希腊民众对贵族政体的抵触。同时,史诗中政体观从一人统治的君主政体转变为少数人统治的贵族政体,这一变化为后世城邦时代多数人统治的民主政体的萌发和发展提供了土壤。     

The age and size of the universe

Modern distance determinations to galaxies were reviewed and placed on a uniform and self-consistent scale. Based on eight separate but not entirely independent techniques, the distance to the Virgo cluster was found to be 15.8 +/- 1.1 megaparsec. Twelve different determinations yield a Coma/Virgo distance ratio of 5.52 +/- 0.13 and hence a Coma distance of 87 +/- 6 megaparsec. With a cosmological redshift of 7210 kilometers per second, this gives a Hubble parameter H(0) (local) of 83 +/- 6 kilometers per second per megaparsec. From the velocity-distance relation of rich clusters of galaxies, the ratio of the value of H(0) (global) to the value of H(0) (local) was determined to be 0.92 +/- 0.08. In other words, the cluster data do not show a statistically significant difference between the local and global values of the Hubble parameter. If one nevertheless adopts this relation between H(0) (global) and H(0) (local), then the value of H(0) (global) is 76 +/- 9 kilometers per second per megaparsec. This observed value differs at the approximately 3sigma level (where sigma is the standard deviation of the distribution) from values in the range 36 less, similar H(0) less, similar50 kilometers per second per megaparsec, which are derived from stellar evolutionary theory in conjunction with standard cosmological models with a density parameter (Omega) that is equal to 1 and a cosmological constant (lambda) that is equal to 0.     

Mapping the universe

Maps of the galaxy distribution in the nearby universe reveal large coherent structures. The extent of the largest features is limited only by the size of the survey. Voids with a density typically 20 percent of the mean and with diameters of 5000 km s(-1) are present in every survey large enough to contain them. Many galaxies lie in thin sheet-like structures. The largest sheet detected so far is the "Great Wall" with a minimum extent of 60 h(-1) Mpc x 170 h(-1) Mpc, where h is the Hubble constant in units of 100 km s(-1) Mpc(-1). The frequent occurrence of these structures is one of several serious challenges to our current understanding of the origin and evolution of the large-scale distribution of matter in the universe.     

The first stars in the universe and cosmic reionization

The earliest generation of stars, far from being a mere novelty, transformed the universe from darkness to light. The first atoms to form after the Big Bang filled the universe with atomic hydrogen and a few light elements. As gravity pulled gas clouds together, the first stars ignited and their radiation turned the surrounding atoms into ions. By looking at gas between us and distant galaxies, we know that this ionization eventually pervaded all space, so that few hydrogen atoms remain today between galaxies. Knowing exactly when and how it did so is a primary goal of cosmologists, because this would tell us when the early stars formed and in what kinds of galaxies. Although this ionization is beginning to be understood by using theoretical models and computer simulations, a new generation of telescopes is being built that will map atomic hydrogen throughout the universe.