None, really. At least, for us, and now. A black hole can be dangerous if it's very massive (such as a supermassive black hole). But mainly, a black hole would be completely harmless, unless it gets close - and the nearest known black hole is at a distance of about 3000 light-years. Even a supermassive black hole would be harmless at such a distance.
A black hole is more dangerous than a dark hole. Black holes are regions in space with gravitational forces so strong that not even light can escape, while a dark hole does not have a specific scientific definition and may refer to areas of space with lower light or energy levels.
Hardly any. The nearest known black hole is at a distance of about 3000 light-years; even if one of the nearest stars were actually a black hole, it wouldn't be particularly dangerous.
Not much. The closest (known) black hole is at a distance of about 3000 light-years.
Anything that falls into a black hole becomes part of that black hole's mass, which makes the gravity stronger and causes the event horizon to grow larger.
The galactic centre is the central region of a galaxy. Most, if not all galaxies have a supermassive black hole at their centre.
very
A black hole is more dangerous than a dark hole. Black holes are regions in space with gravitational forces so strong that not even light can escape, while a dark hole does not have a specific scientific definition and may refer to areas of space with lower light or energy levels.
Hardly any. The nearest known black hole is at a distance of about 3000 light-years; even if one of the nearest stars were actually a black hole, it wouldn't be particularly dangerous.
Not much. The closest (known) black hole is at a distance of about 3000 light-years.
When you get close to a black hole, it will stretch you to where all your insides get crushed.
A black hole.
The most dangerous type of rhino is the black rhino.
Anything that falls into a black hole becomes part of that black hole's mass, which makes the gravity stronger and causes the event horizon to grow larger.
As a black hole.As a black hole.As a black hole.As a black hole.
Quasars have a large black hole, called a "supermassive black hole". The term "supermassive black hole" simply means that it has millions or even billions of solar masses.
Very, even light ain't escape their gravity. A black hole might be the ultimate Doomsday weapon, scientists are attempting to create the phenomena on a smaller scale in the lab. for an interesting story about the subject, see Disney's "The Black Hole"
As far as we know, most, if not all galaxies have a massive black hole at their centre.