|Manu||Date: Thursday, 28-May-2020, 5:10 PM | Message # 1|
|Astronomers find 'missing matter', solving decades-long mystery of outer space|
After an intergalactic search lasting more than two decades, an Australian-led team of scientists say they have finally found the universe's "missing matter", solving a mystery that has long stumped astronomers.
Since the mid-90s, scientists have been trying to locate half of the universe's ordinary matter. They believed it was out there because of clues left over from the Big Bang, but it had never been seen.
"What we're talking about here is what scientists call baryonic matter, which is the normal stuff that you and I are made of," said Associate Professor Jean-Pierre Macquart, from the Curtin University node of the International Centre for Radio Astronomy Research.
Astronomy is full of missing stuff. Most of the universe is understood to be "dark matter" and "dark energy", which nobody has ever directly seen. But even more of a mystery for astronomers was that they couldn't find about half the ordinary matter in the universe.
"It's been a true embarrassment that we haven't been able to find it," said Professor Xavier Prochaska, an astronomer from the University of California, Santa Cruz.
'Putting to bed a cosmic mystery'
Astronomers had been looking at the universe using all sorts of different forms of light — from radio waves through to x-rays and visible light. None revealed the missing matter.
That was until they started to measure fast radio bursts — brief flashes of intense energy found racing across the universe — and discovered the missing matter hiding in the cold dispersed gas between galaxies.
"Intergalactic space is very sparse. The missing matter was equivalent to only one or two atoms in a room the size of an average office," Dr Macquart said.
Fast radio bursts (FRBs) were first detected in 2007, but are not fully understood.
As FRBs travel across the universe, they are dispersed and slowed by the matter they pass through. Each frequency of radio energy is slowed down differently by that matter.
Read more/full article/source - https://www.abc.net.au/news....2291788