The name black hole gives people a sense of mystery. They think it will be a gloomy mysterious object. But it's actually a little scary, but it's actually very simple. It has been said that a black hole is the simplest celestial body in the universe, because it has only three physical quantities, that is, it can be accurately described by only three physical quantities: mass, charge and angular momentum. These three physical quantities are all known black holes.
The black hole that most people have heard of actually has only one physical quantity, so it is the simplest celestial body in the universe, and it is called the Schwarzschild black hole. It is a celestial body with only one physical quantity, namely mass, given by schwarzschild radius's formula. If a certain mass is substituted into schwarzschild radius's formula, a radius can be calculated. When all the mass is concentrated in this radius, celestial bodies will become invisible, because the limit of the speed of light in the universe cannot escape this radius. The sphere formed by this radius is called the visual interface, and the spherical celestial body bounded by this visual interface is called a black hole. Technically, it is called schwarzschild black hole.
According to the general theory of relativity, the visual interface of a black hole is a one-way film, and the interior of the visual interface is one-way, so no object (including light) in the horizon will run to the horizon. In other words, all objects falling into the horizon will irreversibly fall into the singularity at the center of the black hole. The reason why it is irreversible is that space-time has been interchanged in the horizon, and the direction from the visual interface to the central singularity has changed from the space direction to the time direction. Therefore, it seems to me that the object falling into the horizon falls into the singularity not along the space direction, but along the time direction. Singularity is defined as the point where time is zero in general relativity, which is the end of time in human terms!
Schwarzschild black hole is a very extreme black hole, which requires very harsh initial conditions: the total charge is zero and the total angular momentum is zero, that is, it is uncharged and does not rotate. This is basically impossible for a massive celestial body formed by the collapse of the core of a massive star at the end of its life, so there is generally no Schwartz black hole in the strict sense in nature.
So what is a black hole in nature? To be sure, they are generally black holes with spins, which are called kerr black holes. As for whether the belt is charged, it is generally believed that it will be charged, but we are not sure about this.
About kerr black holes, it is actually a Schwarzschild black hole rotating at high speed, which is relatively simple, but much more complicated than Schwarzschild black hole. The black hole in the sci-fi movie Interstellar is an extreme kerr black holes. It is extreme because its spin speed is extremely high, which is close to the theoretical upper limit of its spin speed.
This is kerr black holes, КаΥан and tuya in the interstellar space, which is the equatorial plane close to its spin. Did you find that its left and right sides are asymmetrical? This is a typical feature of kerr black holes. What we see is the accretion disk of the black hole, which will rotate around the black hole in one direction at a high speed under the drag of time and space generated by kerr black holes's high-speed spin, so that the accretion disk on one side will approach us at a high speed, while the accretion disk on the other side will be far away from us at a high speed, resulting in a serious Doppler effect, resulting in the accretion disk near one side being brighter than the accretion disk far away from that side.
Kerr black holes's theoretical drawing is more in line with the facts, but it may lead to the lack of aesthetic feeling of black holes, so it is not shown in the film. We can learn the peculiar features of kerr black holes from the film, because the scientific adviser of this film is the highest authority of general relativity, and Kip, winner of the 20 17 Nobel Prize in Physics? Thorne, so you can actually think of this movie as a popular science enlightenment movie.
In the movie, the protagonist Cooper falls into the hyperspace where high-dimensional civilization is placed next to the singularity of the black hole. You're right, it's right next to a singularity, but this singularity is not the central singularity in the Schwarzschild black hole, but an extreme kerr black holes-specific flying singularity that rotates around the central singularity. Theoretically, the curvature of this singularity of space-time is not as great as that of the central singularity, and because it rotates around the central singularity at high speed, Cooper will pass it in a very short time when he meets it, and Cooper's body will be preserved.
What do you see from the picture above? Yes, there is also a falling singularity, which, like the flying singularity, rotates around the central singularity at high speed in the extreme kerr black holes, and the singularity where Aitas sends the singularity data to Cooper and records the data is the falling singularity.
Do you already think that black holes are not simple at all? In fact, there are more complicated ones, that is, charged black holes.