Key to evolution of universe found, says space probe
‘Dark Matter Detected For First Time’
Jonathan Leake
Scientists may have detected dark matter — the mysterious substance thought to make up 85% of the universe — for the first time.
They have discovered a surge of high-energy particles from the heart of the Milky Way, Earth’s home galaxy, which closely matches the radiation signature predicted for dark matter. Details of the particles, detected by a European space probe, emerged at a cosmology conference in Stockholm.
“This is very exciting research,” said professor Carlos Frenk, a leading theoretical physicist and director of the institute for computational cosmology at Durham University, who attended the conference. “Dark matter holds the key to the evolution of the universe but it has never been detected before.”
The idea that visible matter, such as galaxies, stars and planets, is just a fraction of the universe’s mass was first put forward in 1933.
Astronomers had realised that many galaxies — the clusters of stars that dominate the visible universe — were moving so fast they should fly apart. Their survival over billions of years implied that each galaxy contained far more matter than astronomers could see and that this “dark matter” generated the extra gravity needed to hold galaxies together.
The theory has been strengthened by the observation that light from distant galaxies often appears to have followed a curved trajectory on its way to Earth as if it had been bent by the gravity from some invisible source.
Such calculations suggest that 85% of the universe’s mass is dark matter, with only 15% being visible. However, despite 75 years of theorising and hundreds of millions of pounds spent on satellites and experiments, astronomers have never detected dark matter directly.
Scientists believe that dark matter is made of particles called neutralinos which do not interact with ordinary matter. Billions pass through the Earth, and our bodies, every second. They are also transparent, which is why the clouds of dark matter pervading space do not block our view of other stars and galaxies.
In Stockholm, Mirko Boezio, who worked on the discovery, said that the probe, called Pamela, had detected a surge of positrons — a form of antimatter. The observation fitted predictions that dark matter would be concentrated in galactic cores becoming so dense that particles collide and smash each other apart, emitting positrons. SUNDAY TIMES
They have discovered a surge of high-energy particles from the heart of the Milky Way, Earth’s home galaxy, which closely matches the radiation signature predicted for dark matter. Details of the particles, detected by a European space probe, emerged at a cosmology conference in Stockholm.
“This is very exciting research,” said professor Carlos Frenk, a leading theoretical physicist and director of the institute for computational cosmology at Durham University, who attended the conference. “Dark matter holds the key to the evolution of the universe but it has never been detected before.”
The idea that visible matter, such as galaxies, stars and planets, is just a fraction of the universe’s mass was first put forward in 1933.
Astronomers had realised that many galaxies — the clusters of stars that dominate the visible universe — were moving so fast they should fly apart. Their survival over billions of years implied that each galaxy contained far more matter than astronomers could see and that this “dark matter” generated the extra gravity needed to hold galaxies together.
The theory has been strengthened by the observation that light from distant galaxies often appears to have followed a curved trajectory on its way to Earth as if it had been bent by the gravity from some invisible source.
Such calculations suggest that 85% of the universe’s mass is dark matter, with only 15% being visible. However, despite 75 years of theorising and hundreds of millions of pounds spent on satellites and experiments, astronomers have never detected dark matter directly.
Scientists believe that dark matter is made of particles called neutralinos which do not interact with ordinary matter. Billions pass through the Earth, and our bodies, every second. They are also transparent, which is why the clouds of dark matter pervading space do not block our view of other stars and galaxies.
In Stockholm, Mirko Boezio, who worked on the discovery, said that the probe, called Pamela, had detected a surge of positrons — a form of antimatter. The observation fitted predictions that dark matter would be concentrated in galactic cores becoming so dense that particles collide and smash each other apart, emitting positrons. SUNDAY TIMES
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