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Black holes warp the universe into a grotesque hall of mirrors

By Paul Sutter
livescience.com
22 July, 2021


Imagine a galaxy reflected in a fun house hall of mirrors. You'd see the galaxy, repeated again and again, with each image becoming more grotesque and distorted. That's how the universe looks near the event horizon of a black hole, one of the most warped places in the cosmos.

While physicists had some previous ideas about what such regions looked like, a new calculation has shown exactly what you would see around black holes, opening up potential new ways to test Einstein's theory of general relativity.

The area near a black hole is very strange indeed. Looking directly at the heavy object wouldn't give your eyes much to focus on; light rays get swallowed by the black hole's event horizon, the point at which nothing can ever escape its massive gravitational influence.

But if you were to place a galaxy behind the black hole and then look off to the side, you'd see a distorted image of the galaxy. That's because some light from the galaxy would barely graze the edges of the black hole, without falling in.

Because of the black hole's extreme gravity, such light would get bent toward your line of sight. Strangely, the galaxy would appear to be far away from the black hole, not directly behind it.

The gravity around black holes is so intense, and space-time is so incredibly warped, that at a certain distance, light itself can orbit the black holes. Some of the light from a background galaxy even gets trapped, looping forever.

However, the light would need to come the exact right distance from the black hole to get trapped in an orbit. It can also hit the black hole at an angle that allows it to make one (or many) loops before eventually escaping.

(...)

https://www.livescience.com/amp/black-hole-mirror-copies.html
 
Black holes warp the universe into a grotesque hall of mirrors

By Paul Sutter
livescience.com
22 July, 2021


Imagine a galaxy reflected in a fun house hall of mirrors. You'd see the galaxy, repeated again and again, with each image becoming more grotesque and distorted. That's how the universe looks near the event horizon of a black hole, one of the most warped places in the cosmos.

While physicists had some previous ideas about what such regions looked like, a new calculation has shown exactly what you would see around black holes, opening up potential new ways to test Einstein's theory of general relativity.

The area near a black hole is very strange indeed. Looking directly at the heavy object wouldn't give your eyes much to focus on; light rays get swallowed by the black hole's event horizon, the point at which nothing can ever escape its massive gravitational influence.

But if you were to place a galaxy behind the black hole and then look off to the side, you'd see a distorted image of the galaxy. That's because some light from the galaxy would barely graze the edges of the black hole, without falling in.

Because of the black hole's extreme gravity, such light would get bent toward your line of sight. Strangely, the galaxy would appear to be far away from the black hole, not directly behind it.

The gravity around black holes is so intense, and space-time is so incredibly warped, that at a certain distance, light itself can orbit the black holes. Some of the light from a background galaxy even gets trapped, looping forever.

However, the light would need to come the exact right distance from the black hole to get trapped in an orbit. It can also hit the black hole at an angle that allows it to make one (or many) loops before eventually escaping.

(...)

https://www.livescience.com/amp/black-hole-mirror-copies.html
Mind blown!!
 
Latest episode of Brian Cox’s Universe is about black holes

As usual you have to put up with him in various unnecessary locations but worth a watch.
 
After an hour of explaining black-holes Prof Cox concluded the programme with saying nobody can explain black-holes, because in a larger reality there is no such thing as time and space. Thanks Brian.
 
As usual you have to put up with him in various unnecessary locations ...

that's because black holes are really like waterfalls where stuff moves faster than the speed of light.
Not one of Brian's clearer expositions, IMO
 
After an hour of explaining black-holes Prof Cox concluded the programme with saying nobody can explain black-holes, because in a larger reality there is no such thing as time and space. Thanks Brian.
What did you expect? since nobody knows what goes on inside a black hole. It was just about what’s known so far. The space time weirdness & ‘deeper underlying structure’ implication is just too far out to grasp & hasn’t been generally accepted but [I think] is more theory based on maths, & maths doesn’t lie, but the history of our black hole was interesting, at least to me.
 
What did you expect? since nobody knows what goes on inside a black hole. It was just about what’s known so far. The space time weirdness & ‘deeper underlying structure’ implication is just too far out to grasp & hasn’t been generally accepted but [I think] is more theory based on maths, & maths doesn’t lie, but the history of our black hole was interesting, at least to me.
I found it fascinating, even though me and Physics parted company when I was 12. I was just waiting for an idiot's guide to Hawkings Radiation so I could concile the notion of nothing escaping a black-hole with something escaping a black-hole.
 
I found it fascinating, even though me and Physics parted company when I was 12. I was just waiting for an idiot's guide to Hawkings Radiation so I could concile the notion of nothing escaping a black-hole with something escaping a black-hole.
Emissions from black holes are one of the newer findings/theories. Before that it was thought nothing could escape a black hole. Don’t ask me anything about Hawkings Radiation though.

In the history part the theory is that a huge amount of matter was emitted from the black hole which spread to the outer reaches of the galaxy & slowed down star formation. So theory says it’s happened in the past, several billion years ago..
 
Emissions from black holes are one of the newer findings/theories. Before that it was thought nothing could escape a black hole. Don’t ask me anything about Hawkings Radiation though.

In the history part the theory is that a huge amount of matter was emitted from the black hole which spread to the outer reaches of the galaxy & slowed down star formation. So theory says it’s happened in the past, several billion years ago..

Hawking radiation is a quantum process: a particle pops into existence just outside the black hole's boundary and escapes: its a VERY slow process. The huge amounts of matter spread around the galaxy by the black hole comes from a halo of stuff orbiting the black hole at vast velocities: so not emitted from the black hole itself. I don't think Brian Cox made this clear.
 

Astronomers baffled by black hole burping out spaghettified star years after eating it

Astronomers have spotted a black hole mysteriously spewing up chunks of a devoured star several years after consuming it.

The event, which scientists have classified as AT2018hyz, began in 2018 when astronomers saw the black hole ensnare a hapless star in its strong gravitational pull before shredding it to pieces. Then, three years later, in 2021, a New Mexico radio telescope picked up a signal indicating unusual activity — the black hole had begun burping the star out at half the speed of light.

Black holes have previously been spotted gobbling down stars before vomiting them out, but until now, the ejection has only ever taken place at the same time as the meal. The researchers used four Earth-based observatories located around the globe and two observatories in space to spot the event
"This caught us completely by surprise — no one has ever seen anything like this before," lead author Yvette Cendes(opens in new tab), an
astrophysicist at the Harvard and Smithsonian Center for Astrophysics, said in a statement.

Black holes are messy eaters that like to play with their food. A black hole’s consumption of a star is called a tidal disruption event (TDE) because of the powerful tidal forces that act upon the star from the black hole's gravity. As the star is reeled ever closer to the black hole's maw, the black hole's tidal forces strip and stretch the star layer by layer; transforming it into a long, noodle-like string that gets tightly wound around the black hole like spaghetti around a fork to form a ball of hot plasma. This is known as spaghettification. This plasma quickly accelerates around the black hole and spins out into an enormous jet of energy and matter, which produces a distinctive bright flash that optical, X-ray and radio-wave telescopes can detect.

But AT2018hyz is unusual: Not only did it wait for three years after snacking on the star to emit a flash, but the speed of the material sent flying from its mouth is staggering. Most TDE outflows travel at 10% the speed of light, but the ejected star matter of AT2018hyz is traveling as fast as 50% the speed of light.

"We have been studying TDEs with radio telescopes for more than a decade, and we sometimes find they shine in radio waves as they spew out material while the star is first being consumed by the black hole," study coauthor Edo Berger(opens in new tab), a professor of astronomy at Harvard University, said in the statement. "But in AT2018hyz there was radio silence for the first three years, and now it's dramatically lit up to become one of the most radio luminous TDEs ever observed.”
Full report at the Astrophysical Journal
 
Dead and alive at the same time: Black holes have quantum properties

By Tereza Pultarova
1 November, 2022
.
Black holes have properties characteristic of quantum particles, a new study reveals, suggesting that the puzzling cosmic objects can be at the same time small and big, heavy and light, or dead and alive, just like the legendary Schrödinger's cat.
(End of extract)

This further extract, is arguably the only thing therein which makes sense!

"But whatever that is, it is probably even more fantastic than we could imagine".

https://www.space.com/black-holes-have-quantum-properties-study
 
Biggest Black Hole found.

Astronomers say they have found one of the universe's largest black holes to date using a new technique.

Scientists at Durham University discovered the "ultramassive" black hole by observing its pull on passing light, called gravitational lensing.

Dr James Nightingale who led the study said even he struggled to "comprehend how big this thing is".

Their findings have been published in the journal Monthly Notices of the Royal Astronomical Society.

The academics said the black hole was 30 billion times the size of our Sun and was the first to be measured using gravitational lensing.

Graphic showing light arcing around a black hole
IMAGE SOURCE, DURHAM UNIVERSITY Image caption, Scientists said the way the light arc showed it was being affected by a large black hole

Dr Nightingale told BBC Radio Newcastle: "Even as an astronomer, I find it hard to comprehend how big this thing is.

"If you look at the night sky and count up all the stars and planets you can see and put them in a single point, it would be a fraction of a percent the size of this black hole. This black hole is bigger than the majority of galaxies in the universe."

He said the discovery "pushes our understanding of astronomy to the limits", adding: "How do you form a black hole this big in just 13 billions years of the universe's existence?"

https://www.bbc.com/news/uk-england-tyne-65109663
 
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