Hawking’s Black Hole Theorem Confirmed by New Merger
▼ Summary
– Stephen Hawking predicted in 1971 that a black hole’s surface area cannot decrease, only increase or remain stable, known as Hawking’s area theorem.
– Analysis of a January black hole merger’s gravitational signal provides the best observational evidence to date supporting this theorem.
– The LIGO/Virgo/KAGRA collaboration detects gravitational waves from black hole and neutron star mergers using laser interferometry across multiple global detectors.
– LIGO’s instruments are highly sensitive to ambient vibrations, requiring extensive shielding and noise reduction to detect gravitational wave signals.
– The first simultaneous detection of gravitational waves by LIGO in September 2015, from a black hole merger, led to the 2017 Nobel Prize in Physics.
A new analysis of gravitational wave data has provided the strongest observational confirmation yet of Stephen Hawking’s black hole area theorem, a foundational idea in theoretical physics first proposed in 1971. The study, published in Physical Review Letters, centers on a black hole merger detected in January, offering compelling evidence that the surface area of a black hole can never decrease, only grow or stay the same.
This landmark finding coincides with the tenth anniversary of the LIGO collaboration’s Nobel Prize-winning first detection of gravitational waves from a black hole merger. A related paper, currently under review, explores theoretical limits on a predicted higher-pitch tone that may be hidden within the gravitational wave signal of the same event.
The international LIGO/Virgo/KAGRA (LVK) collaboration continues to scan the cosmos for ripples in spacetime caused by cataclysmic events like black hole and neutron star mergers. Using laser interferometry, LIGO’s facilities measure infinitesimal changes in distance between mirrors placed kilometers apart. The project operates twin detectors in Hanford, Washington and Livingston, Louisiana, joined in 2016 by Advanced Virgo in Italy. Asia’s first gravitational-wave observatory, KAGRA, was built underground in Japan, while construction is underway on LIGO-India, expected to become operational after 2025.
These instruments are extraordinarily sensitive, capable of registering even minor ambient disturbances, from distant trains to thermal vibrations within the equipment itself. To ensure data integrity, the collaboration employs extensive shielding and noise-reduction strategies. On September 14, 2015, both LIGO detectors recorded nearly simultaneous signals for the first time, milliseconds apart. The distinctive waveform served as an audible signature of two black holes spiraling toward collision, merging in an event that sent shockwaves across the fabric of spacetime. That historic detection earned the 2017 Nobel Prize in Physics, cementing gravitational wave astronomy as a transformative field of scientific inquiry.
(Source: Ars Technica)