Three U.S. scientists won the 2017 Nobel prize for physics on Tuesday for opening up a new era of astronomy by detecting gravitational waves, ripples in space and time foreseen by Albert Einstein a century ago.
The work of Rainer Weiss, Barry Barish and Kip Thorne crowned half a century of experimental efforts by scientists and engineers.
Measuring gravitational waves offers a new way to observe the cosmos, helping scientists explore the nature of mysterious objects including black holes and neutron stars. It may also provide insight into the universe's very earliest moments.
The first detection of the waves created a scientific sensation when it was announced early last year and the teams involved in the discovery had been widely seen as favourites for Tuesday's prize.
"We now witness the dawn of a new field: gravitational-wave astronomy," Nils Martensson, acting chairman of the Nobel Committee for Physics, told reporters.
Because gravitational waves are radically different from electromagnetic ones such as radio waves, visible light, infrared light and X-rays, they are expected to reveal previously inaccessible features.
"This will teach us about the most violent processes in the universe and it will lead to new insights into the nature of extreme gravity."
Dr. Weiss said the award of the nine million Swedish kroner ($1.4-million) prize was really a recognition of around 1,000 people working on wave detection, including some Canadian researchers.
University of Toronto astrophysics professor Harald Pfeiffer led a research group that contributed by providing calculations of the expected waveform shapes.
"It's a great feeling, for my research field to have received the Nobel Prize, a dream come true that capped so many decades of work by so many researchers," Prof. Pfeiffer said. "Despite the spectacular successes that were recognized by the Nobel Prize, gravitational wave astronomy is still an infant research area, and I am looking forward to many more decades of new insights from gravitational waves into the cosmos and gravity."
Two U.S.-based instruments working in unison, called the Laser Interferometer Gravitational-Wave Observatory (LIGO), detected the first waves caused by colliding black holes. A European sister facility, known as VIRGO, based in Italy, has also detected waves more recently.
Those spotted so far have come from very distant black holes – extraordinarily dense objects whose existence was also predicted by Einstein – that smashed together to form a single, larger black hole.
The signals from gravitational waves are extremely weak when they reach Earth and therefore require exquisitely accurate measurement.
"These represent some of the most precise measurements that are made by physicists," Nobel committee member David Haviland told Reuters.
Designed to pick up tiny vibrations as they pass through the Earth, the laser detectors spot changes thousands of times smaller than an atomic nucleus.
The scientists then convert the wave signal into sound waves and can listen to the "chirps" of the black holes merging.
Luis Lehner, a faculty member with the Perimeter Institute for Theoretical Physics in Waterloo, Ont., was not involved in the discovery but was delighted by the news.
"This is wonderful news and greatly deserved recognition to Rainer, Kip and Barry," he said. "Major discoveries await thanks to this new lens on the universe. What's more, we will soon be able to detect both gravitational and electromagnetic waves, providing humankind with information about our universe from multiple cosmic messengers."
Physics is the second of this year's crop of Nobel Prizes and comes after Americans Jeffrey Hall, Michael Rosbash and Michael Young were awarded the Nobel Prize for physiology or medicine on Monday.
The prizes for achievements in science, literature and peace were first awarded in 1901 in accordance with the will of Swedish business tycoon Alfred Nobel, who bequeathed much of the fortune he generated from his discovery of dynamite.
Among the science prizes, physics has often taken centre stage with laureates including superstars such as Einstein, Niels Bohr and Marie Curie, one of only two women to win a Nobel prize in physics.
Dr. Weiss won half of this year's prize, with Dr. Barish and Dr. Thorne sharing the other half.
With files from Ivan Semeniuk