Trio win Nobel for research on black holes

Roger Penrose of Britain, Reinhard Genzel of Germany and Andrea Ghez of the US won the Nobel Physics Prize on Tuesday for their research into black holes. The physicists were selected "for their discoveries about one of the most exotic phenomena in the universe, the black hole," the Nobel Committee said.

Penrose, 89, was honoured for showing "that the general theory of relativity leads to the formation of black holes", while Genzel, 68, and Ghez, 55, were jointly awarded for discovering "that an invisible and extremely heavy object governs the orbits of stars at the centre of our galaxy," the jury said.

Ghez is just the fourth woman to receive the physics prize since 1901 when the first Nobel prizes were handed out.

"I hope I can inspire other young women into the field," Ghez told a press conference after the award was announced. The term "black hole" refers to a point in space where matter is so compressed as to create a gravity field from which even light cannot escape.

Penrose, who is based at the University of Oxford, used mathematical modelling to prove back in 1965 that black holes can form, becoming an entity from which nothing, not even light, may escape.

His calculations proved that black holes -- super dense objects formed when a heavy star collapses under the weight of its own gravity -are a direct consequence of Einstein's general theory of relativity.

Genzel and Ghez have led research since the early 1990s focusing on a region called Sagittarius A* at the centre of the Milky Way.

Using the world's largest telescopes, they discovered an extremely heavy, invisible object -- around 4 million times greater than the mass of our Sun -- that pulls on surrounding stars, giving our galaxy its characteristic swirl. The pair in particular developed methods to see through the huge clouds of interstellar gas and dust to the centre of the Milky Way, creating new techniques to compensate for the image distortion caused by Earth's atmosphere. In April 2019, astronomers unveiled the first photo of a black hole.