The surface of A is impossible Black hole Decreases over time. Developed in 1971 by the famous physicist Einstein’s theory of general relativity, this theory actually reflects a fundamental law of physics: the second law of thermodynamics, which states that only entropy (disorder) of a closed system can develop. Researchers are now confirming Hawking’s theory using gravitational waves.

Entropy cannot decrease over time. However, the entropy of a black hole is proportional to its area; So both dimensions must inevitably increase. According to Hawking’s interpretation of general relativity, the area of ​​a black hole does not decrease as its mass increases and no object is thrown out of it.

But the area of ​​the black hole decreases and it rotates by itself. The researchers wondered if a black hole could throw an object inside it to rotate fast enough to reduce its area. ” You can spin it more, but it’s not enough to balance the mass you just added. No matter what you do, the mass and rotation will ensure that you end up in a large area », Maximiliano IC summarizes, Astronomer at MIT and lead author of the study.

The law of surfaces confirmed by calculation

To confirm the famous theory, two giant researchers analyzed the space-time waves created 1.3 billion years ago. Black holes It quickly orbited each other and eventually merged into a large black hole. The surface of a black hole is limited by its event horizon – the boundary from which nothing escapes the gravitational field of a black hole. According to surface theory, the event horizon of the newly formed black hole must be at least as large as the event horizons of the two real black holes.

Gravitational waves were discovered in 2015 based on calculations Laser Interferometer Gravitational-Wave Observatory (LIGO). By dividing the gravitational wave data before and after the merger into two time fractions, they were able to determine the mass and rotational speed of the two black holes over a period of time, allowing them to rise to the surface.

As a result, the area of ​​the new black hole was found to be larger than the area of ​​the two original black holes, which Hawking’s area law confirmed with more than 95% confidence. This is the first time that scientists have been able to quantify this phenomenon. In other words, this team of physicists proves that the increase in area due to excess composite mass is always greater than the space lost during rotation.

The general theory of relativity, from which the law of surfaces derives, is effective in depicting black holes – or any other large-scale object. However, things get complicated when quantum mechanics, which are described infinitely small, get involved: strange things happen, and some are completely contrary to the law of the surface.

A law against quantum mechanics

Stephen Hawking has developed another theory, according to which a black hole must evaporate over a very long period of time (beyond the age of the universe). This theory, ” Hawking radiation The event of a black hole caused by strange quantum effects describes a small amount of radiation emitted near the horizon. Therefore, black holes cannot shrink according to general relativity, but they can shrink according to quantum mechanics.

Since this “evaporation” can occur on excessively long-term scales, it does not actually violate the law of short-term surfaces. But this contradiction still haunts physicists: ” Statistically, over a long period of time, the law is being violated », Emphasizes IC. The specialist makes an analogy of a pot of boiling water: “ If you limit yourself to seeing the water disappear inside, you may be tempted to say that the entropy of the pan decreases. If you consider the vapor, your overall entropy has increased. The same is true for black holes Neutrons .

Confirmation of the surface law suggests that the properties of black holes provide important clues about the hidden laws governing the universe. Researchers now plan to gather information from more gravitational waves to improve their understanding of these interesting and mysterious objects. ” I like them because of the paradox of these things. They are extremely mysterious and confusing, but at the same time we know they are the simplest things that exist. ”Said EC.

The goal is to understand the source of the contradiction between the two theories – surface law, general relativity in general, and quantum mechanics – perhaps leading to new physics.

Source: Physical Review Letters, m. EC et al.