Tag Archives: Albert Einstein

Black hole discoveries win 2020 Nobel Prize in Physics

By Niklas Pollard and Douglas Busvine

STOCKHOLM/BERLIN (Reuters) – Britain’s Roger Penrose, Reinhard Genzel of Germany and American Andrea Ghez won the 2020 Nobel Prize for Physics on Tuesday for their discoveries about one of the most exotic phenomena in the universe, the black hole.

Penrose, professor at the University of Oxford, won half the prize of 10 million Swedish crowns ($1.1 million) for his work using mathematics to prove that black holes are a direct consequence of Albert Einstein’s general theory of relativity.

Genzel, of the Max Planck Institute and University of California, Berkeley, and Ghez, at the University of California, Los Angeles, shared the other half for discovering that an invisible and extremely heavy object governs the orbits of stars at the center of our galaxy.

Ghez – only the fourth woman to be awarded the Physics prize after Marie Curie in 1903, Maria Goeppert-Mayer in 1963 and Donna Strickland in 2018 – said she hoped it would inspire others.

Asked about the discovery of a massive yet invisible object at the heart of the Milky Way, Ghez said “the first thing is doubt”.

“You have to prove to yourself that what you are really seeing is what you think you are seeing. So, both doubt and excitement,” the 55-year-old astronomer said in a call with the committee after receiving the award.

“It’s that feeling of being at the frontier of research when you have to always question what you are seeing.”

Genzel, 68, told Reuters Television soon after hearing he had shared the prize that had been on a Zoom call with colleagues when the phone rang.

“Just like in the movies, a voice said: ‘This is Stockholm’,” he said. He admitted to being flabbergasted by the news: “I cried a little bit.”

WHERE TIME ENDS

Scientists have wondered since the 18th century whether any object existed in the universe that would exert a gravitational pull so strong that light may not be able to escape.

Einstein predicted in 1915, in his general theory of relativity, that space and time could be warped by the force of gravity. Yet he did not actually believe in black holes, and finding a way to prove their existence baffled scientists for another 50 years.

“It was a theory – there was nothing to make black holes visible,” said Genzel.

It was not until a seminal paper in 1965 that Penrose, now 89, proved that black holes can really form – describing them in detail and stating that, at their center, time and space cease to exist.

Illustrating Penrose’s insight at the awards presentation in Stockholm, Ulf Danielsson of the Nobel Committee held a black ball the size of a grapefruit in one hand and pointed at it with the finger of his other hand.

At the ball’s edge, time stands still, Danielsson said, and as his finger pushed into it, its tip moves into the future.

It would be impossible to withdraw one’s finger without tearing it apart. Instead it would be “carried all the way into the center of the black hole, where time ends and the known laws of physics cease to apply”.

‘AWE-INSPIRING’ MYSTERY

Subsequent efforts to find a black hole focused on the clouds of dust in a region of the Milky Way called Sagittarius A*. By observing movements of stars, teams of astronomers led by Genzel and Ghez concluded that around 4 million solar masses are packed into a region the size of our solar system.

“Penrose, Genzel and Ghez together showed us that black holes are awe-inspiring, mathematically sublime, and actually exist,” said Tom McLeish, professor of natural philosophy at Britain’s University of York.

While black holes are now accepted science, much about them remains a mystery.

“What is the black hole? We don’t know, we have no idea what is inside a black hole and that is what makes these things such exotic objects,” said Ghez.

Physics is the second of this year’s crop of Nobels to be awarded, after three scientists won the medicine prize for their discovery of Hepatitis C on Monday.

The Nobel prizes were created in the will of Swedish dynamite inventor and businessman Alfred Nobel and have been awarded since 1901.

This year’s awards are taking place under the long shadow of the COVID-19 pandemic that has curtailed much of the usual festivities surrounding the prizes. ($1 = 8.9108 Swedish crowns)

(Reporting by Niklas Pollard and Douglas Busvine; Additional reporting by Johannes Hellstrom, Supantha Mukherjee, Simon Johnson, Colm Fulton and Anna Ringstrom; Editing by Alex Richardson)

‘Seeing the unseeable’: Scientists reveal first photo of black hole

The first ever photo a black hole, taken using a global network of telescopes, conducted by the Event Horizon Telescope (EHT) project, to gain insight into celestial objects with gravitational fields so strong no matter or light can escape, is shown in this handout photo released April 10, 2019. Event Horizon Telescope (EHT)/National Science Foundation/Handout via REUTERS

By Will Dunham

WASHINGTON (Reuters) – Using a global network of telescopes to see “the unseeable,” an international scientific team on Wednesday announced a milestone in astrophysics – the first-ever photo of a black hole – in an achievement that validated a pillar of science put forward by Albert Einstein more than a century ago.

Black holes are monstrous celestial entities exerting gravitational fields so vicious that no matter or light can escape. The photo of the black hole at the center of Messier 87, or M87, a massive galaxy in the relatively nearby Virgo galaxy cluster, shows a glowing ring of red, yellow and white surrounding a dark center.

The research was conducted by the Event Horizon Telescope (EHT) project, an international collaboration begun in 2012 to try to directly observe the immediate environment of a black hole using a global network of Earth-based telescopes. The announcement was made in simultaneous news conferences in Washington, Brussels, Santiago, Shanghai, Taipei and Tokyo.

The team’s observations strongly validated the theory of general relativity proposed in 1915 by Einstein, the famed theoretical physicist, to explain the laws of gravity and their relation to other natural forces.

“We have achieved something presumed to be impossible just a generation ago,” said astrophysicist Sheperd Doeleman, director of the Event Horizon Telescope at the Center for Astrophysics, Harvard & Smithsonian.

Doeleman said the research “verifies Einstein’s theory of gravity in this most extreme laboratory.”

Black holes, phenomenally dense celestial entities, are extraordinarily difficult to observe by their very nature despite their great mass. A black hole’s event horizon is the point of no return beyond which anything – stars, planets, gas, dust and all forms of electromagnetic radiation – gets swallowed into oblivion.

The black hole observed by the scientific team resides about 54 million light-years from Earth. A light year is the distance light travels in a year, 5.9 trillion miles (9.5 trillion km). This black hole is an almost-unimaginable 6.5 billion times the mass of the Sun.

“This is a huge day in astrophysics,” said U.S. National Science Foundation Director France Córdova. “We’re seeing the unseeable.”

“It did bring tears to my eyes, Córdova added.

RING OF LIGHT

The fact that black holes do not allow light to escape makes viewing them difficult. The scientists look for a ring of light – hot disrupted matter and radiation circling at tremendous speed at the edge of the event horizon – around a region of darkness representing the actual black hole. This is known as the black hole’s shadow or silhouette.

The scientists said Einstein’s theory predicted the shape of the shadow would be almost a perfect circle – as it turned out to be.

Astrophysicist Dimitrios Psaltis of the University of Arizona, the EHT project scientist, said, “The size and shape of the shadow matches the precise predictions of Einstein’s general theory of relativity, increasing our confidence in this century-old theory.”

“Imaging a black hole is just the beginning of our effort to develop new tools that will enable us to interpret the massively complex data that nature gives us,” Psaltis added.

“Science fiction has become science fact,” University of Arizona astronomy professor Daniel Marrone said.

The project’s researchers obtained the first data in April 2017 using radio telescopes in the U.S. states of Arizona and Hawaii as well as in Mexico, Chile, Spain and Antarctica. Since then, telescopes in France and Greenland have been added to the global network. The global network has essentially created a planet-sized observational dish.

The project also targeted another black hole – Sagittarius A* is situated at the center of our own Milky Way galaxy – but did not announce any pictures of that one, though scientists expressed optimism about getting such an image. Sagittarius A* possesses 4 million times the mass of our sun and is located 26,000 light-years from Earth.

(Reporting by Will Dunham; Editing by Sandra Maler and Paul Simao)

In first, scientists detect gravitational waves and light from star collision

An artist’s illustration of two merging neutron stars. The rippling space-time grid represents gravitational waves that travel out from the collision, while the narrow beams show the bursts of gamma rays that are shot out just seconds after the gravitational waves.

By Scott Malone

CAMBRIDGE, Mass. (Reuters) – Scientists in the United States and Europe have for the first time detected gravitational waves, the ripples in space and time predicted by Albert Einstein, at the same time as light from the same cosmic event, according to research published on Monday.

The waves, caused by the collision of two neutron stars some 130 million years ago, were first detected in August in the Laser Interferometer Gravitational-Wave Observatories, known as LIGO, in Washington state and Louisiana as well as at a third detector, named Virgo in Italy.

Two seconds later, observatories on earth and in space detected a burst of light in the form of gamma rays from the same path of the southern sky, which analysis showed likely to be from the same source.

Less than two years have passed since scientists working at the Massachusetts Institute of Technology and the California Institute of Technology first detected gravitational waves coming off two black holes.

The gravitational waves had been predicted by Einstein in 1916, as an outgrowth of his groundbreaking general theory of relativity, which depicted gravity as a distortion of space and time triggered by the presence of matter.

Three U.S. scientists who made that discovery were awarded the Nobel prize in physics earlier this month.

The findings published on Monday help confirm Einstein’s theory, said the researchers, whose work was published in Physical Review Letters.

“From informing detailed models of the inner workings of neutron stars and the emissions they produce, to more fundamental physics such as general relativity, this event is just so rich,” said MIT senior research scientist David Shoemaker. “It is a gift that will keep on giving.”

The LIGO instruments work in unison and use lasers to detect remarkably small vibrations from gravitational waves as they pass through the earth.

Previously, scientists could only study space by observing electromagnetic waves such as radio waves, visible light, infrared light, X-rays and gamma rays. Those waves encounter interference as they travel across the universe, but gravitational waves do not, meaning they offer a wealth of additional information.

The colliding neutron stars were smaller than the black holes that LIGO previously detected.

Black holes are so dense that not even photons of light can escape their gravity. Neutron stars are relatively small, about the size of a city, the compact remains of a larger star that died.

The National Science Foundation, an independent agency of the U.S. government, provided about $1.1 billion in funding for the LIGO research over 40 years.

 

(Reporting by Scott Malone; Editing by Peter Cooney)