Gravitational wave detection confirms Einstein and Hawking's 'prophecy' about black holes

Scientists have just recorded the most detailed gravitational wave signal from a black hole collision, thereby confirming for the first time two important predictions by Einstein and Hawking about black holes are correct.

When two black holes merge, they create ripples in space called gravitational waves. Detectors on Earth can “catch” these signals, helping scientists better understand the universe - Photo: Maggie Chiang/Simons Foundation

Black holes, "cosmic monsters" with gravitational forces so strong that even light cannot escape, have long been a fascinating topic for scientists.

Despite appearing in the theoretical works of Albert Einstein more than a century ago and being studied extensively by Stephen Hawking in the 20th century, black holes remain the most inaccessible subject in the universe because of their "invisible" nature.

Gravitational waves: the key to unlocking the door to black hole research

In 2015, the LIGO Gravitational Wave Observatory (USA) recorded for the first time gravitational waves, ripples in space and time caused by two black holes colliding far away in the universe. This discovery was likened to "opening a new sense" to observe the universe, and also provided the opportunity to directly verify theories about black holes.

However, the initial data are not detailed enough to confirm two important predictions.

One is Einstein's Kerr Theory . According to general relativity, black holes can be described by only two basic properties: mass and spin. All other properties "disappear" when falling into a black hole, known as the "no hair theorem".

Second is Hawking's Area Theorem . Stephen Hawking predicted in 1971 that the area of ​​a black hole's event horizon, the boundary from which nothing can escape, can only remain the same or increase over time, never decreasing.

This is considered a principle similar to the second law of thermodynamics, which states that the entropy (degree of disorder) of the universe is always increasing.

Breakthrough after a decade

According to Sciencedaily , the international LIGO-Virgo-KAGRA collaboration recently published new research results in the journal Physical Review Letters . They recorded the most detailed gravitational wave signal ever, originating from the collision of two black holes (event GW250114), forming a giant black hole with a mass 63 times that of the Sun and rotating up to 100 times per second.

Thanks to cutting-edge technology, scientists have for the first time obtained a “full picture” of both before and after the merger of two black holes. From this data, they have confirmed two hypotheses at the same time:

Black holes are indeed described precisely by mass and spin, just as predicted by Einstein's general theory of relativity.

The area of ​​the event horizon only increases after the merger, in accordance with Hawking's area theorem.

Einstein (right) and Hawking (left) had accurate assessments of the nature of black holes - Photo: MashableIndia

From black holes to the nature of the universe

The proof of Hawking's theorem reveals an uncanny resemblance between black holes and thermodynamics. In other words, the growth of a black hole's area is like an increase in entropy, implying that black holes may be a "mathematical window" into our understanding of the nature of space, time, and the greatest endeavor of modern physics: the unification of general relativity and quantum mechanics into a theory of quantum gravity.

"This is the clearest evidence yet that black holes in the universe really do conform to Einstein's theory," said Maximiliano Isi, a member of the research team. "The fact that the area of ​​a black hole obeys the same law as entropy has profound implications for the nature of the universe."

In the next decade, gravitational wave detectors will be 10 times more sensitive than they are today. A successor to the Laser Interferometer Space Antenna telescope is under construction, promising to pick up vibrations from supermassive black holes at the center of our galaxies.

More than 100 years after Einstein predicted black holes with mathematical equations, and more than half a century after Hawking proved them theoretically, humanity has now begun to directly "hear" and "see" the signals that prove them right.

Black holes, which once existed only in science books, are gradually becoming "real" entities before the eyes of astronomers, and each recorded gravitational wave signal is a step forward in helping humans better understand the mysterious universe we live in.

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MINH HAI

Source: https://tuoitre.vn/phat-hien-song-hap-dan-xac-nhan-tien-tri-cua-einstein-va-hawking-ve-ho-den-20250913075131812.htm