Unlike stars, the moon and the sun which were probably the first astronomical objects discovered by man, black holes successfully managed to escape our attention until not very long ago. The reason is not that difficult: the gravitational force of a black hole is so strong that even light cannot escape it. Hence, they remain dark in the sky and cannot be seen.
Black holes vary in size. Some are incredibly small, as small as a single atom, some twenty times the size of our sun and some can be as big as 1 million suns put together. Some of these black holes are very young and some are as old as the universe itself.
So how is a black hole formed? When a massive star dies, it collapses. The dead star then explodes and a black hole is eventually created. Although the idea of a black hole is scary, our planet earth is not threatened by a black hole. No black hole is close enough for the earth to fall prey to its gravitational force.
So there’s no danger of anyone on our planet to be sucked into a massive black hole. But how do we know that? How are we even to determine if black holes exist and where they are? Although black holes cannot be “seen”, it is possible to detect them as the affect the space around them. Stars and other astronomical objects behave differently once they are affected by a black hole. Scientists analyze these differences and determine whether a black hole exists or not.
Ever since black holes were discovered, they have become incredibly popular with scientists. They have also managed to find their way into our imagination and make us wonder. What would happen if we entered a black hole? Would we be torn apart, atom from atom? Or would it lead to another universe? Or maybe, and just maybe, black holes could realize one of mankind’s most ambitious dreams, time travel?