If black holes are really objects from which no light, nor anything else, can escape, how can we detect their presence ? There are three main possibilities which we take in turn. First, there is the discovery by the Cambridge astrophysicist Stephen Hawking that black holes are not completely black. Matter antimatter pairs of particles […]

Two questions arise when discussing the astronomical consequences of the possibility of the existence of black holes .Where would we expect to find them, and how would we detect them ? To form a black hole we need to find places in the Universe which are much denser than their surroundings. The matter in the […]

In 1798 Laplace, in his book the ‘Exposition of the system of the world’, stated the following theorem: a luminous body in the Universe of the same density as the Earth, whose diameter is 250 times larger than the Sun, can, by its attractive power, prevent its light rays from reaching us. Consequently, he continued, […]

A black hole is an invisible object or a region of space in the universe that has such a strong gravitational force that nothing can escape it. Many astronomers believe that there are millions of black holes in the universe. They are invisible because of the fact that they trap anything, even the fastest thing […]