Historical facts Historical facts

Historical facts Historical facts

For thousands of years mankind studied the sky and looked attentively at stars, planets and flaming fires, people used their eyes after that they used the magnifying lens to explore depths of the universe, but their sight remained limited, till the twenty century when they used a new eyes which are the giant telescopes.Then they used telescopes that works with a new method which is different from the visual methods that depends on eyes, as they used radio waves, infrared, X-rays and gamma rays, etc… to see what eye can't see.
At this moment, scientists started to discover secrets of universe,so they discovered galaxies and inside each galaxy a hundreds of billions of stars! and they discovered cosmic smoke the cosmic dust, also they discovered many kinds of stars and the development phases of these stars.They found that when the star is born , it grow up to become elderly to die and explode and fall on himself!
Also, one of wonders of cosmic discoveries what was called by scientists the Neutron stars, and that was in 1933 as an idea of the two scientists Fritz Zwicky and Walter Baade,when they found by calculations that universe contains ordinary stars and Neutron stars as these stars composed of small particles which are neutrons.
Through forty years, scientists started a search journey for these attractive stars, till 1967 when Jocelyn Bell and Anthony Hewish started to observe the sky for a long time and finally they became able to record emitted radio waves from these stars. but the certain scientific prove came at the late twentieth century when scientists became able to take pictures for these stars to study it deeply, where they became sure that it exists in universe in large amounts.