Posted: Mar 21, 2014 2:44 am
by Calilasseia
Pulsar wrote:
Calilasseia wrote:
Reeve wrote:I wonder if this will make Roger Penrose's cosmological model more testable. I seem to remember that his cyclic one was crucially dependent on gravitational waves with the predictions it made.

Ditto for Steinhardt & Turok's model.

Stephen Hawking claims victory in gravitational wave bet

Stephen Hawking has claimed victory in a bet with a fellow scientist over the discovery of primordial gravitational waves, ripples in the structure of space-time from the birth of the universe.

The Cambridge cosmologist bet Neil Turok, director of the Perimeter Institute in Canada, that gravitational waves from the first fleeting moments after the big bang would be detected.

Speaking on BBC Radio 4's Today programme, Hawking said the discovery of gravitational waves, announced on Monday by researchers at the Harvard-Smithsonian Centre for Astrophysics, disproves Turok's theory that the universe cycles endlessly from one big bang to another.

If confirmed by other groups, the discovery would count as the strongest evidence yet for cosmic inflation, a theory which says that the universe went through a period of extremely rapid expansion soon after the big bang. The theory explains why the universe looks almost the same in every direction.

"It is another confirmation of inflation," Hawking told the Today programme. "It also means I win a bet with Neil Turok, director of the Perimeter Institute in Canada, for cyclic universe theory predicts no gravitational waves from the early universe."

But Turok was not ready to concede just yet. He told the programme that the bet rested on results from the European Space Agency's Planck space telescope, which last year failed to spot any signs of gravitational waves.


Er, according to the two papers by Steinhardt & Turok I presented in multiple places here, observations of gravity waves are actually a crucial test in a different manner. According to those papers, what matters is the spectrum of observed gravity waves. My understanding from those papers, is that if gravity waves were never detected, this would be a far bigger blow to the ekpyrotic model. The detection of gravity waves, according to those papers, is actually necessary in order to test the theory.