Nobel physics prize awarded to 3 scientists for discoveries relating to black holes

Three scientists won this year's Nobel Prize in Physics Tuesday for advancing our understanding of black holes, the all-consuming monsters that lurk in the darkest parts of the universe and that still confound astronomers.

Briton Roger Penrose, German Reinhard Genzel and American Andrea Ghez explained to the world these dead ends of the cosmos, where light and even time doesn't escape. These staples of both science fact and fiction are still not completely understood, but they are deeply connected, somehow, to the creation of galaxies, where the stars and life exist.

Penrose, of the University of Oxford, received half of this year's prize "for the discovery that black hole formation is a robust prediction of" Albert Einstein's general theory of relativity, the Nobel Committee said.

Genzel, who is at both the Max Planck Institute in Germany and the University of California at Berkeley, and Ghez, of UCLA, received the second half of the prize "for the discovery of a supermassive compact object at the centre of our galaxy." That object was also a black hole, albeit a giant one.

The prize celebrates what the Nobel Committee called "one of the most exotic objects in the universe" and ones that "still pose many questions that beg for answers and motivate future research."

Black holes are at the centre of every galaxy, and smaller ones are dotted around the universe. Nothing, not even light, can escape their incredible gravity. Time comes to a standstill as it gets closer.

Just their existence is mind-bending, taking what people experience every day on Earth — light and time — and warping them in such a way that seems unreal.

"Black holes, because they are so hard to understand, is what makes them so appealing," Ghez told The Associated Press Tuesday morning. "I really think of science as a big, giant puzzle."

Ghez, 55, went to college as a math major because the concept of infinity fascinated her. Because time slows and even stops in these black holes, Ghez said she is still studying infinity in a way.

"You get this mixing of space and time," Ghez said, adding that's what makes black holes so hard to understand.

Einstein laid foundation

Penrose, 89, proved with mathematics that the formation of black holes was possible, based heavily on Albert Einstein's general theory of relativity.

"Einstein did not himself believe that black holes really exist, these super-heavyweight monsters that capture everything that enters them," the committee said. "Nothing can escape, not even light."

Martin Rees, the British astronomer royal, noted that Penrose triggered a "renaissance" in the study of relativity in the 1960s, and that, together with a young Stephen Hawking, he helped firm up evidence for the Big Bang and black holes.

"Penrose and Hawking are the two individuals who have done more than anyone else since Einstein to deepen our knowledge of gravity," Rees said. "Sadly, this award was too much delayed to allow Hawking to share the credit."

Hawking died in 2018, and Nobel prizes are only awarded to living scientists.

It wasn't until the 1990s that Genzel, 68, and Ghez, each leading a group of astronomers, trained their sights on the dust-covered centre of our Milky Way galaxy, a region called Sagittarius A*, where something strange was going on.

They both found that there was "an extremely heavy, invisible object that pulls on the jumble of stars, causing them to rush around at dizzying speeds," according to the committee.

It was a black hole. Not just an ordinary black hole, but a supermassive black hole, four million times the mass of our sun.

The first image Ghez got was in 1995, using the Keck Telescope, which had just gone online. A year later, another image seemed to indicate that the stars near the centre of the Milky Way were circling something. A third image led Ghez and Genzel to think they were really on to something.

Now scientists know that all galaxies have supermassive black holes.

4th woman to win Nobel for physics 

In 2019, scientists got the first optical image of a black hole, and Ghez, who was not involved, praised the discovery.

"Today we accept these objects are critical to the building blocks of the universe," Ghez told an audience at the Royal Swedish Academy of Sciences by phone shortly after the announcement.

Ghez, who spoke from her home in Los Angeles, was woken by the call from the Nobel Committee at 2 a.m.

"For the first few minutes, I thought I was dreaming," Ghez said in the AP interview.

Ghez is the fourth woman to be awarded the Nobel Prize in Physics, after Marie Curie in 1903, Maria Goeppert-Mayer in 1963 and Donna Strickland in 2018.

"I hope I can inspire other young women into the field. It's a field that has so many pleasures. And if you're passionate about the science, there's so much that can be done," Ghez said.

Canadian-born scientist won in 2019

It is common for several scientists who worked in related fields to share the prize. Last year's prize went to Canadian-born cosmologist James Peebles for theoretical work about the early moments after the Big Bang, and Swiss astronomers Michel Mayor and Didier Queloz for discovering a planet outside our solar system.

The prestigious award comes with a gold medal and prize money of 10 million Swedish kronor ($1.5 million Cdn), courtesy of a bequest left 124 years ago by the prize's creator, Swedish inventor Alfred Nobel. The amount was increased recently to adjust for inflation.

On Monday, the Nobel Committee awarded the prize for physiology and medicine to Americans Harvey J. Alter and Charles M. Rice and British-born scientist Michael Houghton for discovering the liver-ravaging hepatitis C virus.

The other prizes, to be announced in the coming days, are for outstanding work in the fields of chemistry, literature, peace and economics.