For the first time, scientists have witnessed the cataclysmic crash of two ultra-dense neutron stars in a galaxy far away and concluded that such impacts forged at least half the gold in the universe.
Shock waves and light flashes from the collision traveled about 130 million light-years to be captured by detectors on Earth on Aug. 17, excited teams revealed at news conferences held around the globe on Monday as a dozen related science papers were published in top academic journals.
“We witnessed history unfolding in front of our eyes: two neutron stars drawing closer, closer ... turning faster and faster around each other, then colliding and scattering debris all over the place,” joint discoverer Benoit Mours of France’s CNRS research institute said.
The groundbreaking observation solved a number of physics riddles and sent ripples of excitement through the scientific community.
Most jaw-dropping for many, the data finally revealed where much of the gold, platinum, uranium, mercury and other heavy elements in the universe come from.
Telescopes saw evidence of newly-forged material in the fallout, the teams said — a source long suspected, now confirmed.
“It makes it quite clear that a significant fraction, maybe half, maybe more, of the heavy elements in the universe are actually produced by this kind of collision,” said physicist Patrick Sutton, a member of the US-based Laser Interferometer Gravitational-Wave Observatory (LIGO), which contributed to the find.
Neutron stars are the condensed, burnt-out cores that remain when massive stars run out of fuel, blow up and die. Typically about 20km in diameter, but with more mass than the sun, they are highly radioactive and ultra-dense — a handful of material from one weighs as much as Mount Everest.
It had been theorized that mergers of two such exotic bodies would create ripples in the fabric of space-time known as gravitational waves, as well as flashes of high-energy radiation called gamma ray bursts.
On Aug. 17, detectors witnessed both phenomena, 1.7 seconds apart, coming from the same spot in the constellation of Hydra.
“It was clear to us within minutes that we had a binary neutron star detection,” said David Shoemaker, another member of LIGO, which has detectors in Livingston, Louisiana, and Hanford, Washington. “The signals were much too beautiful to be anything but that.”
The observation was the fruit of years of labor by thousands of scientists.
Along with LIGO, they include teams from Europe’s Virgo gravitational wave detector in Italy, and a number of ground and space-based telescopes, including NASA’s Hubble.
“This event marks a turning point in observational astronomy and will lead to a treasure trove of scientific results,” said Bangalore Sathyaprakash from Cardiff University’s School of Physics and Astronomy, recalling “the most exciting [discovery] of my scientific life.”
“It is tremendously exciting to experience a rare event that transforms our understanding of the workings of the universe,” added France Cordova, director of the National Science Foundation, which funds LIGO.
The detection is another feather in the cap for physicist Albert Einstein, who predicted gravitational waves more than 100 years ago.
Three LIGO pioneers — Barry Barish, Kip Thorne and Rainer Weiss — were awarded the Nobel Prize in Physics this month for the observation of gravitational waves, without which the latest discovery would not have been possible.
The ripples have been observed four times before now — the first time by LIGO in September 2015. All four were from mergers of black holes, which are even more violent than neutron star collisions, but emit no light.
The fifth and latest detection was accompanied by a gamma ray burst which scientists said came from nearer in the universe and was less bright than expected.
“What this event is telling us is that there may be many more of these short gamma ray bursts going off nearby in the universe than we expected,” Sutton said — an exciting prospect for scientists hoping to uncover further secrets of the universe.
Among other things, it is hoped that data from neutron star collisions will allow the definitive calculation of the rate at which the cosmos is expanding, which in turn will tell us how old it is and how much matter it contains.
“With these observations we are not just learning what happens when neutron stars collide, we’re also learning something fundamental about the nature of the universe,” said Julie McEnery of the Fermi gamma ray space telescope project.
‘WOULD NOT COMPLY’: The company’s user data are kept in Singapore and it would not turn the data over to Beijing even if asked, TikTok chief executive Kevin Mayer said Social media app TikTok has distanced itself from Beijing after India banned 59 Chinese apps in the country, according to a correspondence seen by Reuters. In a letter to the Indian government dated on Sunday last week and seen by Reuters on Friday, TikTok chief executive Kevin Mayer said the Chinese government has never requested user data, nor would the company turn it over if asked. TikTok, which is not available in China, is owned by China’s ByteDance, but has sought to distance itself from its Chinese roots to appeal to a global audience. Along with 58 other Chinese apps, including Tencent
FOX HUNT: To suppress dissent, Chinese living abroad that Xi Jinping sees as threats are told to either return to China or commit suicide, Christopher Wray said Chinese agents have been pursuing hundreds of Chinese nationals living in the US in an effort to force their return, as part of a global campaign against the country’s diaspora, known as Operation Fox Hunt, FBI Director Christopher Wray said on Tuesday. In a speech about the security threat posed by China, during which he said Beijing’s counterintelligence work was the “greatest long-term threat to our nation’s information and intellectual property, and to our economic vitality,” Wray gave the example of one Fox Hunt target who was given a choice of going back to China or killing themselves. Fox Hunt was launched
‘FIGHT FOR FREEDOM’: Hong Kongers will never bow to Beijing, the advocate said, while the US’ envoy to the territory called China’s new security law a ‘tragedy’ The world must stand in solidarity with Hong Kongers after Beijing imposed sweeping national security legislation on the semi-autonomous territory, advocate Joshua Wong (黃之鋒) said yesterday, vowing to continue campaigning for democracy. Wong, one of the territory’s most prominent young advocates and a figure loathed by Beijing, was speaking outside a court where he and fellow advocates are being prosecuted for involvement in last year’s pro-democracy protests. China last week enacted sweeping security legislation for the restless territory, banning acts of subversion, secession, terrorism and collusion with foreign forces. The legislation has sent a wave of fear through the territory, and criminalized dissenting
A squad of gun-toting police officers patrolled Myanmar’s sacred site of Bagan under the cover of night, taking on plunderers snatching relics from temples forsaken by tourists due to COVID-19 restrictions. Each evening as dusk falls, about 100 officers fan out across the plain of Bagan covering 50km2, sweeping flashlights over the crumbling monuments to scour for intruders. “Our security forces are patrolling day and night,” Police Lieutenant Colonel Sein Win told reporters. “We have it under control for the moment, but it’s a challenge.” The central Burmese city is strewn with more than 3,500 ancient monuments — stupas, temples, murals and sculptures