Dark matter and exoplanet discoveries win Nobel Prize in Physics

Canadian-American cosmologist James Peebles and Swiss astronomers Michel Mayor and Didier Queloz won the Nobel Prize in Physics for research that increases the understanding of our place in the universe.

Peebles won one-half of the prize "for theoretical discoveries that have contributed to our understanding of how the universe evolved after the Big Bang," professor Goran Hansson, secretary-general of the Royal Swedish Academy of Sciences, told a press conference.

Mayor and Queloz shared the other half for the first discovery, in October 1995, of a planet outside our solar system — an exoplanet — orbiting a solar-type star in the Milky Way.

"Their discoveries have forever changed our conceptions of the world," the jury said.

Developed over two decades since the mid-1960s, Peebles' theoretical framework is "the basis of our contemporary ideas about the universe."

Peebles built upon Albert Einstein's work on the origins of the universe by looking back to the millennia immediately after the Big Bang, when light rays started to shoot outwards into space.

'Dark energy'

Using theoretical tools and calculations, he drew a link between the temperature of the radiation emitted after the Big Bang and the amount of matter it created.

His work showed that the matter known to us — such as stars, planets, and ourselves — only make up five percent, while the other 95 are made up of "unknown dark matter and dark energy."

Peebles is Albert Einstein Professor of Science at Princeton University in the US, while Mayor and Queloz are both professors at the University of Geneva. Queloz also works at the University of Cambridge in Britain.

Using custom-made instruments at their observatory in southern France in October 1995, Mayor and Queloz were able to detect a gaseous ball similar in size to Jupiter, orbiting a star around 50 light-years from our own Sun.

Harnessing a phenomenon known as the Doppler effect, which changes the colour of light depending on whether an object is approaching or retreating from Earth, the pair proved the planet, known as 51 Pegasus b, was orbiting its star.

Ceremony in Stockholm

The Nobel jury noted that the discovery "started a revolution in astronomy" and since then over 4,000 exoplanets have been found in our home galaxy.

The prize consists of a gold medal, a diploma and the sum of nine million Swedish kronor (about $914,000)

The trio will receive the prize from King Carl XVI Gustaf at a formal ceremony in Stockholm on December 10, the anniversary of the 1896 death of scientist Alfred Nobel who created the prizes in his last will and testament.