Black hole merger 63 times sun’s mass validates Einstein and Hawking theories

 The Laser Interferometer Gravitational-Wave Observatory (LIGO) has detected new gravitational waves from a merger that resulted in a black hole 63 times the mass of our sun.

Interestingly, it was found spinning at 100 revolutions per second. 

The new data provide the “clearest evidence yet” for long-held fundamental predictions by Albert Einstein and Stephen Hawking.

The development comes ten years after the initial discovery of gravitational waves, which are the ripples in space-time. 

Over the years, LIGO’s improved equipment and techniques have enabled a clearer look at black hole mergers and their gravitational waves.

“The new pair of black holes are almost twins to the historic first detection in 2015. But the instruments are much better, so we’re able to analyze the signal in ways that just weren’t possible 10 years ago,” said Maximiliano Isi, an astrophysicist at Columbia University, who led the measurements.  

“We’ve found some of the strongest evidence yet that astrophysical black holes are the black holes predicted from Albert Einstein’s theory of general relativity,” Isi added.

Black hole’s faint ringing

Massive stars can turn into black holes when they die. Black holes are so dense that nothing, not even light, can escape their gravity. 

The explosive collision of two black holes creates gravitational waves. These ripples are unique to the black holes that created them, allowing scientists to learn about the properties of the colliding objects.

Interestingly, this time, the researchers were able to capture the complete “ringing” of the newly merged black hole.

This was a major improvement over past observations, where the final reverberations were too weak to be separated from the initial collision.

A new method, developed by Isi and his colleagues, was used to isolate the specific “tones” of a black hole’s final, faint ringing after a merger. 

The accurate measurements allowed the team to isolate the milliseconds-long signal confidently. 

“Ten milliseconds sounds really short, but our instruments are so much better now that this is enough time for us to really analyze the ringing of the final black hole,” Isi said 

“With this new detection, we have an exquisitely detailed view of the signal both before and after the black hole merger,” Isi noted in the press release.

Hawking’s theorem

Using higher-quality data, scientists have confirmed a decades-old conjecture that black holes are surprisingly “simple objects.” 

They found that a merged black hole, as described by a 1963 equation from physicist Roy Kerr, can be fully characterized by just two properties: its mass and spin.

The observations also provided solid proof for a foundational idea from Stephen Hawking called Hawking’s area theorem. It states that the size of a black hole’s event horizon — the point of no return — can only ever grow.

Thanks to data with four times better resolution, scientists are now much more confident that Hawking’s theorem is correct.

The confirmation of Hawking’s theorem hints at a link to the second law of thermodynamics, the principle that a system’s entropy must either increase or stay constant.

“It’s really profound that the size of a black hole’s event horizon behaves like entropy. It has very deep theoretical implications and means that some aspects of black holes can be used to mathematically probe the true nature of space and time,” Isi said.

Scientists anticipate that future gravitational wave detections will reveal even more about black holes, as detectors are expected to become 10 times more sensitive.