Black hole discoveries win Nobel physics prize

This year’s Nobel Prize in physics has been shared between three scientists for discoveries about black holes — astronomical objects where matter is compressed to its ultimate limits and the known laws of nature break down.

Half of the SKr10m ($1.1m) award goes to Roger Penrose, the veteran Oxford university cosmologist, for his theoretical discovery in 1965 that black holes really can exist.

The other half is shared by two astronomers, Reinhard Genzel of the Max Planck Institute for Extraterrestrial Physics in Germany and Andrea Ghez of the University of California Los Angeles.

Professors Genzel and Ghez discovered in the 1990s that our Milky Way galaxy has an invisible and extremely heavy object at its centre. This cannot be observed directly but a supermassive black hole, with a mass 4m times greater than the sun, is the only possible explanation.

“The discoveries of this year’s laureates have broken new ground in the study of compact and supermassive objects,” said David Haviland, chair of the Nobel Committee for Physics.

Prof Ghez, 55, is only the fourth woman to win the physics prize since its inauguration in 1901. Speaking by phone to the Nobel announcement press conference in Stockholm she said: “I hope I can inspire other young women into the field.”

Asked what it might be like inside a black hole, she replied: “We have no idea. They represent the breakdown of our understanding of the laws of physics.”

Prof Penrose, who is 89, used mathematics to prove that black holes are a direct consequence of Albert Einstein’s general theory of relativity.

Although Einstein did not himself believe that black holes existed, Prof Penrose showed in 1965 that he was wrong, in what the Nobel committee called “a groundbreaking article . . . still regarded as the most important contribution to the general theory of relativity since Einstein.”

Speaking to journalists from his Oxford home on Tuesday, Prof Penrose said he was happy to receive the “great honour” of a Nobel in his 90th year: “It's a bad thing to get a Nobel Prize too early in your career. It’s good to get it when you're old but not too old.”

Of his seminal 1965 paper, he said, “there was a lot scepticism. It took a long time but it was gratifying to see how people were taking black holes seriously”.

Profs Genzel and Ghez each led teams of astronomers observing stars closest to the middle of the Milky Way. Both found that an extremely heavy object — an invisible black hole — was pulling on the stellar orbits.

More direct observations have followed their work, first of gravitational waves emitted by colliding black holes and then last year the first image of a black hole taken by a global network of radio telescopes.

Other scientists reacted enthusiastically to the awards. Tom McLeish, professor of natural philosophy at the University of York, said: “Penrose, Genzel and Ghez together showed us that black holes are awe inspiring, mathematically sublime, and actually exist. ”

Jim Al-Khalili, professor of physics at the University of Surrey, said: “I can’t tell you how delighted I am that Roger Penrose has been recognised with a Nobel Prize. For many outside of physics he has been seen as being in the shadow of his longtime collaborator, the late Stephen Hawking.”

Martin Rees, the UK’s Astronomer Royal, added: “Penrose is amazingly original and inventive, and has contributed creative insights for more than 60 years. 

“There would, I think, be a consensus that Penrose and Hawking are the two individuals who have done more than anyone else since Einstein to deepen our knowledge of gravity.

Sadly, this award was too much delayed to allow Hawking to share the credit with Penrose.”

Physics is the second of this year’s Nobel Prizes to be announced. On Monday Harvey Alter, Charles Rice and Michael Houghton won the Nobel Prize for medicine for their work discovering the hepatitis C virus. The chemistry award will be announced on Wednesday, followed by literature, peace and finally economics next Monday.