Bővebb ismertető
Men have been fascinated by space since time immemorial. What did those pinpoints of hght in the heavens mean? Surely those glittering strings of beads seemed to form outlines of animals? Or were they human beings? Could the lights be the homes of the gods?Our galaxy consists of about 100,000 million fixed stars, but it is only a tiny part of the Milky Way, which contains some twenty galaxies within a radius of one-and-a-half million light years. (One light year is roughly equal to six million million miles.) Even this figure is small in comparison with the approximately 1,500 million galaxies that have been recorded so far. Where does it come from, this incredible mass of matter that is scattered throughout the universe over many millions of light years? Even today the answers to that question are no more than theories. There is the Big Bang theory. All matter was compressed into one primordial atom, which created such pressure on its own core that it exploded. The galaxies originated from the shower of pieces produced by this heavy mass of matter. In 1842 Christian Doppler proved that if a source of light moves away from the observer, the spectrum shows a shift towards red. The 'Doppler effect' makes it possible to measure the speed of the stars. In 1929 Edwin Powell Hubble was able to