Approximately thirty years ago the famous theorist Albert Einstein proposed that time is effected by the influence of gravity. It was experimentally proven. From this concept he also proposed that there would be a point in the universe where the gravity dominates every other force in the universe, where our mathematical calculations of space-time would be no longer valid a space-time singularity called “Black Hole”.
For years, black hole is just a theory. It became reality when scientists studied dying stars and their behavior. So, what is a Black Hole? Our sun is one of the billion starts in our galaxy. When a star runs out of hydrogen, it collapses. When a star which is 80 times more massive than our sun dies, the star explodes shooting gamma ray bursts. These giant stars are at thousands of light years away. When these stars explode, the gravity at the star’s center continues to concentrate at its center. This gravity is so immense that not even light particles can escape from its influence. At this region the space itself bends into the center which is called a black hole.
As this monster pulls things into its belly, the size of the black hole increases proportionally. We know what happens outside the black hole. But there is a point near black hole where laws of physics are no longer valid. This point is called “Event Horizon”. Experimental physicists around the world did many experiments to know what exactly happens at the Event Horizon.
In Scotland, a physicist, Daniele Faccio who simulates and creates black holes in his laboratory. He did an experiment which shows what really happens at the black hole’s event horizon. In his experiment he used a very powerful laser which was very intense. By shooting lasers into tiny whirlpools he noticed that at the mouth of these artificial black holes the laser beams frozen, which explains the Einstein’s general relativity that time slows down under heavy gravitational influence. At the event horizon you may observe object is not moving at all, but reality is that the time almost freezes at that region.
Recent theory about black holes say that galaxies are formed from the giant black holes called “Super Massive Black holes”. Scientists observed that our Milky Way galaxy contains a super massive black hole at its center. They believe that this black hole is responsible to keep the starts in their orbit, which in turn keeps the planets in their orbit, which made life to originate. So we should be grateful to black holes. Some of the scientists believe that worm holes can be created using black holes. A wormhole is a hypothetical topological feature that would fundamentally be a shortcut through space-time. A wormhole is much like a tunnel with two ends, each in separate points in space-time. But that’s a story for another time.
The key to the door of mystery behind black holes is yet to be found. There are lot of questions like what happens inside a black hole? How black holes got that immense power of gravity? Finding answers to these type of questions may change our understanding of the universe.
– Sai Madhav Attili