Prof. Kristian Zarb Adami

Last week, scientists ‘listened’ as two massive black holes, each 100 kilometres across, circled each other in the void some 1.3 billion years ago.

As the black holes drew closer, they finally combined, smashing together in a violent merger that sent vast amounts of energy hurtling out in the form of gravitational waves.

These waves, tiny distortions in the fabric of space and time, a bit like the ripples on the surface of a pond, had been predicted by Albert Einstein in his theory of general relativity 100 years ago – but until now, they had never been directly detected.

“It heralds a new paradigm in the observation of the universe. In the same way as MRI and X-ray imaging opened up new ways of looking at the human body, this detection of gravitational waves opens up a new observational window on the universe,” said Kristian Zarb Adami, director of the Institute of Space Sciences and Astronomy at the University of Malta.

“Whereas before, most measurements were made by waves travelling through space and time – like light and radio waves – we can now see these infinitesimally small ripples in the fabric of spacetime, locate them and even more impressively work out what caused them,” Prof. Zarb Adami said.

In making the discovery, which is widely expected to win a Nobel Prize, scientists at the Laser Interferometer Gravitational-Wave Observatory (Ligo) used equipment precise enough to pick up a distortion comparable to the width of a human hair in the distance between our solar system and the next.

It heralds a new paradigm in the observation of the universe

Successfully detecting gravitational waves means scientists can eventually peer back at the earliest moments of the universe. Moreover, as light cannot escape from a black hole, the discovery opens huge doors in the way we explore these mysterious bodies.

“One prediction by Stephen Hawking describes exactly what the surviving black hole should look like (after the merger we observed); we can now do this and confirm his prediction,” Prof. Zarb Adami, who is also a lecturer at Oxford University’s Astrophysics Department, said.

“Also, having observed one of these mergers, we can now begin to make predictions of how many there are and where they are within our galaxy.”

As always, however, this discovery is just the beginning.

Jackson Levi Said, an astrophysicist at ISSA who focuses on the study of gravity, points out that while gravitational waves were until now the last missing piece of Einstein’s predictions, actually detecting them will allow scientists to go further and hammer down the edges of Einstein’s theory.

Tiny distortions in space and time. Photo: Laser Interferometer Gravitational-Wave Observatory.

“The whole point is to see more of space in different ways, to refine our theories and ultimately to understand even more of the cosmos,” according to Dr Said.

“Right now, we can only see very exotic things like this black hole merger, but if more attention and funding now come towards it, this could be a ‘Hubble space telescope moment’, creating a whole new generation of astronomy.”

Speaking to The Sunday Times of Malta together with fellow physicist Andre Xuereb, Dr Said explained that any investment into research in the field could pay off not only in scientific advancement but in a host of practical side aspects.

Malta, for example, is currently very interested in work on new ‘quantum technologies’, where the principles of quantum mechanics - which is the branch of physics dealing with subatomic particles - are applied to practical fields from computing to cryptology.

Scientists like Prof. Zarb Adami and Dr Said are also currently working on an international project called the Square Kilometre Array, a large multi-radio telescope project, which will explore huge portions of the sky at up to 10,000 times the speed of current survey telescopes.

“One of the key goals of the project is exploring gravitational waves,” Dr Said said. “A discovery like this raises the profile of the work and allows the scientists involved to spend more time on the actual science rather than arguing for funding.”