Stephen Hawking’s and Einstein’s theories confirmed as scientists ‘hear’ two black holes merging

An illustration of GW250114 shows two black holes colliding, producing gravitational waves detected by LIGO, viewed from the perspective of one of the merging black holes. (Image: Aurore Simonnet (SSU/EdEon)/LVK/URI)

Space has always inspired wonder and mystery, but sometimes science helps us “hear” the cosmos in new ways. On January 14, something historic happened. Two black holes merged, creating a larger black hole. The Laser Interferometer Gravitational-Wave Observatory, or LIGO, sensed the tiny ripples in space-time. These gravitational waves contained distinctive clues. Now, scientists have confirmed a key theory by Stephen Hawking.

What Did LIGO Detect During Black Hole Merger?

The event, labelled GW250114, revealed two black holes merging. Before the collision, their combined surface area was about 93,700 square miles. After merging, the new black hole measured roughly 154,500 square miles. That is bigger than California. This confirmed Hawking’s prediction from 1971. He theorised black hole surfaces can never shrink. The observation confirms the event horizon always expands. This finding allows scientists to better know black holes.

Infographic highlighting advancements in gravitational wave observatories, some of the most precise instruments ever built, capturing black hole collisions with recorded signals displayed in the bottom panel. (Image: Dr. Derek Davis/Caltech, LIGO Laboratory)

Scientists employed sophisticated instruments to record the event. LIGO’s twin detectors in Washington and Louisiana monitored the collision. Their precision has improved since the first gravitational wave detection in 2015. Now, black hole mergers are detected about every three days. This latest event marked a decade of progress. Gravitational waves act like cosmic sound. The pitch and duration reveal black hole properties.

How Does This Support Hawking’s Theory?

Hawking proposed black holes follow a second law. Their surface area cannot decrease, much like entropy always increases. Study co-author Maximiliano Isi explained this is a simple but profound rule. The data analysed showed “ringing” in space-time as the new black hole stabilised. The pattern is similar to a bell’s sound after being struck. This ringdown confirmed the black hole’s larger surface area.

When black holes merge, they create ripples in space-time that LIGO detects on Earth. A newly observed merger could finally confirm a 50-year-old Stephen Hawking theory. (Image: Maggie Chiang for Simons Foundation)

The minerals surrounding the event carry information. They mimic the spin and mass of the black hole. The results also confirm the 1960s Kerr metric theory. It explains how rotating black holes move under general relativity. Scientists now treat black holes as thermodynamic objects. The results suggest the quantum nature of black holes is linked to their size.

What’s Next for Gravitational Wave Research?

Future improvements in detection are planned. LIGO-India is slated to go online around 2030. It will improve accuracy in finding gravitational-wave sources. Other proposals, such as Cosmic Explorer and the Einstein Telescope, envision longer arms on detectors. These will enable scientists to analyse more ancient black hole mergers.

The research, which appeared in Physical Review Letters, is conducted by Adrian G. Abac. It releases the data for further research. Researchers now look to learn more about how the universe functions. Every finding assists in answering the ultimate question: Are we alone in the universe?