What are Some Different Types of Black Holes?

The black hole hairless theorem is 1973, Hawking, B. Carter and others rigorously proved the "black hole hairless theorem": "No matter what kind of black hole, its final property consists of only a few physical quantities (mass, angular momentum, charge ) Uniquely determined " ^[1] .

Black hole hairless theorem

That is, after the formation of a black hole, there are only three conserved quantities that cannot be turned into electromagnetic radiation. All other information (hair) is lost. The black hole has almost no complex properties of the material that formed it. No shape or composition is remembered. In fact, this is a naming principle to reduce complexity and reduce complexity! then"

For a physicist, a black hole or a cube of sugar is an extremely complex object, because a complete description of them, that is, their description including the structure of their atoms and nuclei, requires billions of parameters. In contrast, a physicist studying the outside of a black hole has no such problem. A black hole is an extremely simple object. If you know its mass, angular momentum, and charge, you know everything about it.

A black hole hardly maintains any complex properties of the material that forms it. It has no memory of the shape or composition of its predecessor, it only holds mass, angular momentum, and charge. Reduction of complexity is probably the most basic feature of black holes. York Wheeler, the inventor of most terms about black holes, called this feature "black hole hairless" 60 years ago.

At first, this was just a guess. A rigorous mathematical proof was obtained in the 1970s as a result of 15 years of hard work by theoretical physicists including Brandon Carter of the Meudon Observatory and Gary Banting of Australia. They proved that only three parameters are needed to describe the space-time geometry around an equilibrium black hole, thus confirming Wheeler's formulation.

The parameters of black holes can be accurately measured, albeit with the aid of ideal experiments. You can put a satellite in orbit around a black hole and measure the satellite's orbital period to get the mass of the black hole. The angular momentum of a black hole can be measured by comparing the deflection of light towards different parts of the horizon.

For a Kerr-Newman black hole with a certain mass, both the charge and angular momentum have upper limits, that is, they are both limited by the condition of guaranteed horizon. If this restriction is violated during the gravitational collapse of a massive star, the black hole becomes a naked singularity and can affect long distances in the universe. However, physicists have every reason to believe that this situation is forbidden by the laws of nature and therefore cannot occur.

Since it is dominated by only three parameters, a black hole is as simple as a basic particle. Although elementary particles also concentrate mass, angular momentum, and charge in a small volume. However, as long as you consider the conditions of the horizon, you know that there is nothing more different than the basic particle and the black hole. Taking electrons as an example, experiments have determined its three parameters. For the same mass, the charge and angular momentum of the electrons exceed 10 ^{88 of the} upper limit of the black hole. This amazing number even exceeds the total number of observable elementary universe particles, and this is exactly the difference between an electron and a Kerr-Newman black hole. The hairless theorem is a theorem about the properties of black holes. According to current physics In theory, a black hole has only three physical properties:

In addition to the three conserved physical quantities mentioned above, other black hole information is lost during the process of the object being transformed into a black hole. If the mass, charge and angular momentum of two black holes are the same, then the two black holes are exactly the same measure.