ﻻ يوجد ملخص باللغة العربية
A hundred years ago (1920) in the auditorium of the Smithsonian Institutions U.S. National Museum there were two lectures under the auspices of the George Ellery Hale Lecture series, what has come to be called the Great Debate. In the debate, Harlow Shapley and Heber Curtis argued over the Scale of the Universe. Curtis argued that the Universe is composed of many galaxies like our own and they are relatively small. Shapley argued that the Universe was composed of only one big Galaxy. In Shapleys model, our Sun was far from the center of this great island Universe.
Typicality arguments attempt to use the Copernican Principle to draw conclusions about the cosmos and presently unknown conscious beings within it. The most notorious is the Doomsday Argument, which purports to constrain humanitys future from its cur
Are some cosmologists trying to return human beings to the centre of the cosmos? In the view of some critics, the so-called anthropic principle is a desperate attempt to salvage a scrap of dignity for our species after a few centuries of demotion at
We critically examine the evidence available of the early ideas on the bending of light due to a gravitational attraction, which led to the concept of gravitational lenses, and attempt to present an undistorted historical perspective. Contrary to a w
Although the extragalactic nature of quasars was discussed as early as 1960, it was rejected largely because of preconceived ideas about what appeared to be an unrealistically high radio and optical luminosity. Following the 1962 occultations of the
The physical processes that determine the properties of our everyday world, and of the wider cosmos, are determined by some key numbers: the constants of micro-physics and the parameters that describe the expanding universe in which we have emerged.