Popular myths relating to black holes are numerous
. Most of them are products of Hollywood science fiction films displayed in theatres and TV. Movies often depict these black holes as the path for time travelling into some other dimension. At times they also portray them as the cosmic vacuum cleaners sucking up whatever is in their way.
All such definitions; however attractive they might sound are myths. In reality black holes are the end point of massive stars and they have evolved over time. Huge in size, they are no less than ten to fifteen times of the sun. When a star of such massive dimension experiences supernova explosion, it will naturally leave behind fairly massive burned out stellar remnants.
Since there would be no gravitational force to oppose, remaining parts will collapse on themselves. In result it collapses into zero volume as well as infinite density. A singularity is created with an aura around it with exceptional force of gravity. Even the light cannot escape. Since no information can reach anyone from this particular region to earth, it is called the black hole while its surface is called the event horizon.
Concept that is also a myth is that the black hole is something like the cosmic vacuum cleaner. Even if the Sun is changed with a black hole the orbit of earth around it will remain unchanged. Only change that will take place will be in the temperature of the Earth. Moreover there would be no solar wind or solar magnetic storms invading the earth.
Other wrong notion is that the black hole is that it sucks everything that comes its way. No such thing happens when some object comes the way of the black holes. Only when some object crosses inside the Schwarzschild radius it can be sucked. The object will have to travel at the speed of light to escape at this radius. Moreover when the light passes through it, even such escape won't be possible.
In case the Sun is replaced by black hole with equivalent mass, the Schwarzschild radius would be three kilometres long. Such calculation is made considering the radius of sun that is around 700,000 Kilometre.