Question 1: What does the word "horizon" mean? We often use it in article writing. Vision is the range of vision. The horizon mentioned in this paper is a kind of spiritual cognition of things around us achieved by our own arc. Usually new content, new ideas, etc.

Question 2: What does the horizon mean? Definition 1: The time-space interface where events can be observed is called the horizon. For example, events in a black hole cannot be observed by people outside the black hole, so we can call the interface of the black hole the event horizon.

Definition 2: The boundary of a black hole is called the horizon.

Question 3: The meaning of horizon, the definition of specific point horizon.

The time-space interface where an event can be observed is called the horizon [1]. For example, events in a black hole cannot be observed by people outside the black hole, so we can call the interface of the black hole the event horizon.

Under the global geometry, it can be proved that there is a boundary called horizon in some time and space, which isolates some areas in time and space. The most famous example of this is the black hole: when the mass is compressed into a small enough area in space (the correlation length is schwarzschild radius), no photon can escape from the inside. Because any particle with mass cannot exceed the speed of light, the matter inside the black hole is also enclosed in the horizon. However, the passage from outside the horizon to inside the horizon still exists, which shows that the horizon of a black hole, as a dividing line, is not a barrier of physical properties.

The energy layer of a rotating black hole plays an important role in the process of extracting energy from the rotating black hole. The early study of black holes mainly depended on finding the exact solution of Einstein's field equation. The famous solutions include spherically symmetric Schwarzschild solution (used to describe static black holes) and antisymmetric Kerr solution (used to describe rotating static black holes, and thus introduced interesting properties such as energy layers). Later research revealed more universal properties of black holes through global geometry: research shows that after a long period of time, black holes gradually evolved into a kind of quite simple stars, which can be determined by eleven parameters, including energy, momentum, angular momentum, position and charge at a certain moment. This property can be summarized as the uniqueness theorem of black holes: "Black holes have no hair", that is, black holes have no different marks like different hairstyles of human beings. For example, the process of the gravitational collapse of a star to form a black hole is very complicated, but the nature of the final black hole is quite simple.

What is more worth mentioning is that the study of black holes has obtained a set of universal laws that restrict the behavior of black holes. This law is called black hole (thermal) mechanics, and these laws have strong analogy with the laws of thermodynamics. For example, according to the second law of black hole mechanics, the horizon area of a black hole will never decrease spontaneously with time, which is similar to the entropy of a thermodynamic system; This law also determines that it is impossible to extract energy from a rotating black hole infinitely by classical methods (such as Penrose process). All these strongly indicate that the laws of black hole mechanics are actually a subset of the laws of thermodynamics, and the surface area of a black hole is directly proportional to its entropy. Starting from this hypothesis, the laws of black hole mechanics can be further revised. For example, because the second law of black hole mechanics is part of the second law of thermodynamics, it is known that the surface area of black holes may also decrease, as long as there is some other process to ensure that the total entropy of the system increases. The third law of thermodynamics holds that there is no object with absolute zero degree, and it can be further inferred that black holes should also have thermal radiation; Semi-classical theoretical calculations show that they do have thermal radiation. In this mechanism, the surface gravity of the black hole plays the role of temperature in Planck's law of blackbody radiation, which is called Hawking radiation (see the part about quantum theory below).

General relativity also predicts other types of horizon models: in the expanding universe, observers may find that some areas in the past cannot be observed (so-called "particle horizon") and some areas in the future cannot be affected (event horizon). Even in the straight Minkowski space-time, when the observer is in the accelerated frame of reference, there will be horizons, and these horizons will be accompanied by Anglian radiation in semi-classical theory.

Question 4: What does this sentence mean? The map of the world is visible, known and limited intuitively, but the connection between what you see with your eyes and what you think is infinite.

Question 5: Is Visual Day the world significance of video? Haha, I think so. It is more likely to be a reward from Mi Gu video to the public!

Question 6: What does E-horizon mean? As an all-media news magazine program, E Vision will observe and interpret educational news from the perspective of education, and use the energy of education to drive and change the educational atmosphere.

Question 7: What is Nubian horizon? hi

Nubian Vision is a social application for picture sharing, which can pay attention to friends' dynamics, view popular pictures and interactions, and the shared pictures can directly reach the Nubian Vision section of Nubian Forum.

Real-time sharing records personal life attitude, sharing a beautiful and warm life.

Download link: app.nubia/app/5

Question 8: Vision determines vision. What do you mean, vision determines vision?

A person's vision will determine his or her insight.

Question 9: Microvision live broadcast, what does that light mean? How to light it? Light up to increase the popularity of the anchor. Double-click the screen to light it up. Order it once every live broadcast. For example, this anchor has a live broadcast today. You click in, double-click the screen to light up, and then exit, it won't light up, because you have already lit up. If this anchor is broadcast live the next day, you can still light it by clicking in.