Black holes have for many years been seen as creatures of destruction. Whatever enters is doomed to cease to exist. Recent studies have shown however that they could be portals to other universes or time travelling objects. This article will discuss the nature of black holes and their potential uses.
Black holes are small dense masses with such a strong gravitational pull that nothing escapes them, not evening photons of light; yet amazingly they obey all laws of physics, even the law of gravity.
Black holes have been a wonder of the universe ever since they were predicted in the 18th century by English geologist John Mitchell. He thought it to be theoretically possible for gravity to be so strong that not even light could escape its pull. Though these ideas were carried forward by the French scientist Pierre-Simon Laplace, they unfortunately seemed to just fade away. Not until 1916 did German astrophysicist Karl Schwarzschild revive the idea of black holes and decide to compute the gravitational fields of stars using Einstein’s new field equation. From his calculations, a singularity was yielding as a result. This singularity was theorized to lie at the centre of black holes (the term itself coined by John Wheeler in the 1960’s).
Black holes have never been seen directly; but it is possible to see their gravitational effects on the objects they pull and the objects that fall into them. So how are black holes formed? They come about at the death of a massive star, when all mass is contracted to an infinitesimally smaller mass called the central singularity. At this point, it has huge density (due to such an enormous mass being contained in such a small volume) with an incredibly strong gravitational force. To give you an idea of how dense this actually is, in order to produce a black hole where the earth is, you would have to condense the earth down to the size of a marble.
All black holes are seen as identical except for three key features: mass, spin and charge. It is assumed that black holes have some sort of spin on their axis but this has not been thoroughly proven. Any charge that a black hole has is often thought to be neutralised by the objects it swallows. In recent years scientists have been able to describe such properties using theoretical calculations. Stephen Hawkins’ book “Black Holes and The Baby Universes and other Essays” describes the thermodynamics of a black hole. In 1975, his calculations proposed that black holes weren’t really black but that they emitted something called Hawking radiation. This radiation would consist of mainly photons and neutrinos. The black hole would have to be very small for it to be seen, as in larger black holes the gravity sucks in this weak radiation.
It is pretty obvious that black holes are the stuff of total destruction, leaving nothing in their path. However science fiction often depicts black holes as leading to different universes – an idea often laughed at. But there is some truth in this idea. Einstein’s theory of relativity came up with odd characteristics and predictions of black holes, like them being bridges between our universe and others. Researchers are studying the concept of black holes short cuts to other parts of the universe and the even more exciting possibility of time travel. The idea of time travel is born from the notion that the inside of a black hole is so infinitely dense that the very fabric of the universe is collapsed to a point of infinite curvature. This creates the stage for strange physics to occur.
Black holes don’t last forever; like everything in this universe they obey the law of entropy which states everything moves towards chaos. Black holes are assumed to evaporate, slowly restoring the energy back to the universe.
At a first glance, black holes are seen as a menace with no other purpose sace destruction, but they can lead to promising and interesting concepts. Who knows; in the not so distant future we could discover new universes, new life forms and be able to time travel. Only time will tell whether such possibilities exist.