La collision d'étoiles neutroniques justifie la théorie autrefois ridiculisée des scientifiques israéliens

An artist's impression from the European Southern Observatory showing two tiny but very dense neutron stars at the point at which they merge and explode as a kilonova

HO (European Southern Observatory/AFP) 


Prof. Piran of Hebrew University said he was treated with 'utter contempt' after making the prediction in 1989


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.

But the observation is both exciting and perhaps almost bittersweet for a group of Israeli scientists who predicted the idea which was dismissed by the scientific community at the time. 

“I am exhilarated by this confirmation of a prediction we made nearly 30 years ago,” said Hebrew University’s Professor Tsvi Piran who led a team which published an article in 1989 in the Nature scientific journal, putting forward a theory on the creation of heavy metals. 

“I also remember how difficult it was to convince the scientific community of our idea — at the time it was against the standard model that was published even in freshman textbooks on astronomy,” Piran said, according to the Times of Israel. 

“When we made this prediction in 1989, we did not expect it to be confirmed within our lifetimes. But with continued curiosity and the development of new technologies, we are able learn ever deeper truths about the nature of our Universe.” 

Professor Piran told the Ynet news site that: "It amuses me to remember the early years after this prediction when no one wanted to listen to me and treated me with utter contempt."

HO (European Southern Observatory/AFP)
An image from the Paranal Observatory in Chile shows the galaxy NGC 4993, about 130 million light-years from Earth, where a collision of two neutron stars has just been detected by scientists
HO (European Southern Observatory/AFP)

Shockwaves and light flashes from the collision traveled some 130 million light-years to be captured by Earthly detectors on August 17, excited teams revealed at press 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," co-discoverer Benoit Mours of France's CNRS research institute told AFP.

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 came 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 20 kilometers (12 miles) 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.

(Staff with AFP)


Source : I24