Gravitational waves: making a ripple around the world

The first direct detection of gravitational waves by the two Advanced Ligo interferometers in the US, from the merger of two massive black holes more than a billion light years from Earth, has been a global media phenomenon, with blanket coverage on newspaper front pages, news bulletins and websites worldwide.

As perhaps befits a discovery so important for Einstein’s general theory of relativity, the human story of how we discovered gravitational waves also stretches far across both space and time.

It reaches back 100 years to Einstein’s pioneering prediction of these tiny ripples in the fabric of the cosmos – which he believed were too elusive ever to be detected – and since then across many decades of perseverance, ingenuity and determination as the huge technological barriers to making such an insanely difficult measurement were overcome one by one.

And the discovery – and the research that made it possible – spans the globe: the result of a worldwide collaboration featuring thousands of scientists in hundreds of laboratories and institutions based in dozens of countries. 

In this sense our discovery feels like a triumph for Big Science: for the vision and commitment of the National Science Foundation and the UK’s Science and Technology Facilities Council (among several other national agencies) to invest long term in a project so challenging that many were sure it would never succeed; and for the perseverance of the hundreds of scientists involved who have devoted their entire careers to a quest that many had regarded as an academic dead end.

For an individual UK academic, however, the day-to-day experience of being part of a Big Science collaboration such as Ligo can be strange and disorienting at first. To begin with, there’s the problem of managing your diary, and balancing teaching and administrative commitments across the regular working week when so much of your research time involves teleconferences that stretch well into the night. Then there’s adjusting to the deluge of emails that awaits you each morning, from colleagues across the world who keep the balls rolling – and the questions coming – while Glasgow sleeps.   

Increasingly, with the research excellence framework and impact agendas ever more important in the UK, there’s also the need to strike a balance between the short-term quest for 4* papers, and the collaboration’s long timelines for carrying out thorough and painstaking analyses; with the resulting publications authored by many hundreds of scientists. All of this seems in stark contrast to the widely held (albeit somewhat mythological!) perception of Albert Einstein himself, working in quiet isolation as the “lone genius” in his Swiss patent office.

It doesn’t take long for the Big Science experience to grow on you, however. Sharing the excitement of discovery with a global scientific “family” – all of whom are passionate, idealistic and supremely dedicated – is endlessly rejuvenating.

The past five months since “detection day” in September 2015 have surely been the most intense of my scientific career, and the past few weeks have taken that intensity to an even higher level as we frantically prepared for our 11 February press conference and the tidal wave of media and public attention that followed it. And yet throughout these months I have constantly marvelled at the energy and commitment of the Ligo team across the world. No stone was left unturned as the collaboration strove to make our discovery announcement (and the suite of scientific papers that underpin it) as rigorous, comprehensive and clearly communicated as we could possibly make it.

That the global impact of our discovery has been so far-reaching has surprised and delighted us all. And perhaps even more exciting is the fact that this is not the end of the story – it’s just the beginning, with many more discoveries ahead as we open an entirely new window on the universe.

But first up, in just three weeks’ time, I’ll join the Ligo collaboration for our spring meeting in Pasadena. It’s going to be quite a family reunion!

Martin Hendry is professor of gravitational astrophysics and cosmology at the University of Glasgow, and a member of the Ligo Scientific Collaboration.