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UofT contributes to work of Nobel Prize team

U of T contributes to work of team
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U of T contributes to work of team

TORONTO — Ontario researchers were part of the large team that contributed to the work done by three U.S.-based professors who were awarded the Nobel Physics Prize for their detection of gravitational waves, a theory first put forward by Albert Einstein more than 100 years ago.

The three scientists won the prize on Tuesday for detecting the faint ripples flying through the universe.

University of Toronto astrophysics professor Harald Pfeiffer and several students helped the team discover that the collision of two black holes caused the waves.

“It’s great to be part of a team doing such good research,” Pfeiffer said in a telephone interview from his family home in Germany.

Pfeiffer and his team were among about 1,000 scientists in more than 20 countries who collaborated on the project that was about 50 years in the making.

The Royal Swedish Academy of Sciences that awards Nobel Prizes said the detection of the waves promises a revolution in astrophysics.

Rainer Weiss of the Massachusetts Institute of Technology and Barry Barish and Kip Thorne of the California Institute of Technology won the 2017 prize for a combination of highly advanced theory and ingenious equipment design, the academy announced.

Gravitational waves are “perturbations in space and time itself that travel at the speed of light,” Pfeiffer explained.

These waves can be created by a variety of ways, Pfeiffer said, although the collision of two black holes or two neutron stars are “the best sources for gravitational waves.”

The waves were predicted by Einstein a century ago as part of his theory of general relativity, which states that gravity is caused by heavy objects bending space-time, which itself is the four-dimensional way that astronomers see the universe.

Weiss in the 1970s designed a laser-based device that would detect gravitational waves. He, Thorne and Barish “ensured that four decades of effort led to gravitational waves finally being observed,” the Nobel announcement said.

The laser device, called an interferometer, must be both exquisitely precise and extremely stable.

The first detection of gravitational waves involved two of the devices about 3,000 kilometres apart — in Hanford, Wash., and Livingston, La. The wave first passed the Livingston facility and 7 milliseconds later at Hanford, consistent with the speed of light.

Pfeiffer said when one of these gravitational waves passes through Earth, the diameter of Earth changes by roughly the size of a proton.

“It’s incredible that the detectors are actually able to measure these ridiculously small changes in length space,” he said.

Pfeiffer’s contribution to the project involved computer calculations of colliding black holes. His work helped predict the waveforms the detector should be looking for, he said.

Thus far, he said, the team has detected four gravitational waves, all from black holes colliding with each other.

Pfeiffer says he is celebrating with his family tonight in Germany, but will get back to work tomorrow as the team hunts for more gravitational waves.