Day359 Black Holes 黑洞

Day359 Black Holes 黑洞

Astronomers and scientists think that a Black Hole is a region of space, not a thing into which matter has fallen and from which nothing can escape, not even light, so we can't see a Black Hole. A Black Hole exerts a strong gravitional pull and yet it has no matter, it is only space, or so we think, how can this happen. The theory is that some stars explode when their density increases to a particular point. They collapse and sometimes a supernova occurs. From earth a supernova looks like a very bright light in the sky, which shines even in the daytime. The collapse of a star may produce a wide door or nutron star, a star whose matter is so dense that it continuely shrinks by the force of its own gravity, but if the star is very large, much bigger than the sun, this process of shrinking may be so intense that a Black Hole results. Any matter near the Black Hole will be sucked in. It is impossible to say what happens inside a Black Hole. Scientists have called the boundary area around the Hole ---the event horizon. We know nothing about events which happen once objects pass this boundary. Our space and time loss don't seem to apply to objects in the area of a Black Hole. Einstein's relativity theory is the only one which can explain such phenomenon. Einstein claimed that matter and energy are interchangeable,so that there is no absolute time and space. There are no constance at all and measurements of time and space depend on the position of the observer. They are relative. We do not yet fully understand the implications of the relativity theory but it is interesting that Einstein's theory provided a basis for the idea of Black Holes before astronomers started to find some evidences for their existence. The story of Black Holes is just beginning. Speculations about them are endless. There might be a massive Balck Hole at the center of our galaxy. Swallowing up stars at a very rapid rate, mankind may one day meet this fate.