The incredible snap was taken by the Event Horizon Telescope (EHT)– the same instrument that captured the first-ever image of a black hole in 2019. The telescope has been probing Sagittarius A* – a supermassive black hole located at the centre of our galaxy – the Milky Way – since 2015. Now, the European Southern Observatory (ESO) has shared its “groundbreaking” discovery.
Sagittarius A*, roughly 27,000 light-years away, has been under the scope of astronomers for the last five decades.
Its event horizon – the boundary around a black hole where nothing can escape once crossed – has a radius of around six million kilometres.
But it is buried by all the gas and dust of the Milky Way, making it harder to spot than the black hole previously observed at the centre of Messier 87 (M87).
The holy grail for astronomers is to directly observe the immediate environment of a black hole at an angular resolution comparable to the dimensions of the event horizon.
Such observations offer the best way to probe directly the strong gravitational effects that are experienced near the regions of spacetime.
This, experts at ESO say “opens a new avenue for testing general relativity”.
Black holes are the product of the famous theory developed by Einstein between 1907 and 1915 on how gravity warps the fabric of spacetime.
Now, Dr Mark Norris, from the University of Central Lancashire, tells Express.co.uk, a huge breakthrough could be on the cards.
He said: “Physics has done this amazing job of describing the entire universe in terms of four forces of nature – gravity, electromagnetism, the strong and weak nuclear forces.
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“The problem is, three of those forces – the electromagnetic, and the strong and weak nuclear forces – can all be described by one law of nature – quantum mechanics.
“Gravity cannot. We can describe perfectly what it does, but we cannot describe how it does it.
“So there must be gravitational law that fits quantum mechanics and the problem is, on Earth, we don’t have access to the extreme gravity needed to probe the limits of Einstein’s gravity, it works perfectly as far as we can tell”
“If you go to the most extreme gravity you can get – a black hole – the laws of physics start to break down and the clues start to be seen.
“The great hope is that those clues, signs that Einstein’s gravity doesn’t quite fit, will lead us to this new improved theory of gravity that is compatible with quantum mechanics.”
Dr Norris, a senior lecturer in astrophysics, says such a breakthrough “would be revolutionary”.
He added: “It would be the final theory of everything – a single law of physics that describes all the forces of nature.
“[With that discovery,] Einstein’s law will need to be edited.
“Newton’s law works perfectly well in the Solar System up to the point that you get to Mercury, then gravity gets too strong and you have to switch to Einstein’s description.
“It’s just a more complicated, more accurate description.
“Whatever law of gravity we come up with still has to reduce to being just like Einstein’s law and just like Newtons in the way they have been tested.
“It won’t be revolutionary in that sense, but it will allow us to make gravity to work in extreme conditions.”