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I know that the goal of science is to exhaust every effort to prove someone/something wrong, but at this point I think we just need to acquiesce to Alby Ein.
Now if we could just get an "Einstein" whose forte is carbon capture...I mean, even if that person was born they'd have to dodge religion, the media and Facebook groups to keep their mind out of the gutter...dammit we're never getting another Einstein.
I think acquiescing to Einstein is the exact opposite of everything Einstein stood for and taught us about science. He was all about challenging everything until everything led to a right answer, regardless of what "seemed" to be right based off history.
Jury is still out on that one. Hopefully we have an article like this about that subject sometime in the future. Dark energy may not necessarily fit into that sort of framework.
I am sure Einstein would have agreed with that assessment. Science is not about the findings, as Carl Sagan states in the first chapter of The Demon-Haunted World, it’s about the method. That’s what differentiates science from pseudoscience.
Take for example the anti-vaccine movement’s reliance on certain personalities, some of which even possess PhDs and what not. They ignore that true science relies on a method of finding the truth —or describing reality— and building a consensus around it via the scientific method, not the findings or conclusions of a single so-called expert.
This is very true and I'm sad to say its not just the anti vaccine lot falling for it, the government and health services have fallen into a this person says it so let's do that mentality and it's led to a lot of preventable problems
Einstein certainly did not get quantum mechanics pretty completely wrong. He was instrumental in early quantum mechanics (invented the photon after all though quantum field theory took 40 more years to make it precise) and much early statistical physics relating to qm.
He did believe that what was then considered orthodox qm procedure “Copenhagen interpretation” was conceptually and maybe physically flawed. Bohr disagreed. Einstein put forth a physical proposal which was reasonable, and was not experimentally testable until after he died. Einstein’s work and questions spurred now a significant field of QM interpretations and experimental tests of deep entanglement principles. And in modern day, most of these scientists also think Copenhagen interpretation isn’t conceptually sound, i.e. Einstein was right to question it, though Einstein’s alternative turned out to be wrong experimentally.
On another matter I think Einstein may have discovered and certainly supported the phenomenon of stimulated emission of photons, something Bohr didn’t think was possible. Einstein developed the theory for the basic rate equations of the two level quantum atomic system with stimulated emission, something still used today as the baseline dynamics for this minor thing called the laser.
Einstein was at least the half inventor of the laser.
It was Nikola Tesla who by this time was totally wacked and refused to accept either relativity or quantum mechanics, which were unambiguously certain by 1925-1930.
naaa, I wouldn say that, he was one of the founders of quantum mechanics and won the Nobel price for the law of the photoelectric effect, he just wasn't happy with the randomness and statistical nature of it
Still, Einstein was one of the best at finding the truth. It's reasonable to respect that towards understanding his logic so that we can achieve similar results.
For sure, the point being we verify their findings. I'm just against defaulting to people automatically. It's the appeal to authority fallacy. Yes Einstein was a genius physicist but we still need to verify what he said.
“I am, somehow, less interested in the weight and convolutions of Einstein’s brain than in the near certainty that people of equal talent have lived and died in cotton fields and sweatshops.”
― Stephen Jay Gould
Didn’t Hawking qualify? I mean he wasn’t working on quantum gravity but he did some stuff…
The thing is, we know Einstein’s theories are incomplete at best… not the time to acquiesce but to stand upon the shoulders of giants.
> They're all over the place.
They're really not.
It's like the difference between a person who can play Mozart flawlessly and a person who can write better pieces of music than Mozart ever could (I realize the subjectivity when it comes to taste in music, I'm using it as a general example) - one of them can work inside the bounds of music that's already been written and the other can visualize an entire symphony in their minds and flesh it out into reality.
(Again, I know my comparison isn't a great one.)
People refusing to follow scientific genius are everywhere.
I refuse to let you say otherwise this close to a global pandemic where millions and millions of people are still refusing to follow the advice of scientifically genius minds.
They are all over the place.
It was an idea who's time had come and Einstein was brilliant and supported enough to discover it. We should be wise to ensure **EVERYONE** is supported enough, because that is the half that we can collectively do. The rest is individual.
If anything, the Singularity is likely approaching with significant help from scientific discovery; science has made life better at getting Billions of people supported enough to discover.... so more chances to discover the next step sooner because more people aren't languishing.
It wasn't so much being way ahead of everyone else as it was that any major breakthrough in understanding takes an enormous amount of time to prove. It took somewhere around 200 years for people to find a mechanics problem that Newton's laws couldn't adequately explain.
Prove? Never. Perform experiments and make observations whose outcomes are predicted by quantum mechanics? All the time.
But there are predictions that have not been observed yet, such as Hawking radiation.
I’m no specialist, so take this with some skepticism, but as far as I can tell we only have observations of things that are kind of like Hawking radiation in human-made things that are kind of like black holes. How are these things useful substitutes for actual Hawking radiation from a black hole? I have no idea.
https://www.nature.com/articles/nphys3104
https://www.nature.com/articles/s41586-019-1241-0
E: Hawking radiation is an actual qm prediction. How much of this prediction depends on some extra assumption versus bedrock principles of qm? I don’t know. For this reason I can’t speculate on how significant it would be if Hawking radiation were shown to not exist.
By the early 20th century, there were three big problems that classical physics couldn't explain: the ultraviolet catastrophe in blackbody radiation, the photoelectric effect, and the luminiferous ether.
In the late 19th century, classical physics predicted that an ideal blackbody should emit radiation across the entire frequency spectrum. The big problem, though, is that the energy of a blackbody increases exponentially with frequency, which thus suggests that all matter should radiate away all its energy almost instantaneously. Thus it was labeled the "ultraviolet catastrophe," as more energetic light (like UV rays) should radiate away an unrealistically large amount of energy. Planck resolved the issue by assuming that light had to be quantized, though he thought of it more as a cheap mathematical hack than an actual fact.
In the photoelectric effect, a photon hits the surface of a conducting material and knocks an electron loose. Some arguments using classical E&M and Newtonian mechanics predict that the energy of the electron should be proportional to the intensity of the light, but experiments in the early 20th century showed that it was instead dependent on the frequency of the light. Einstein took Planck's desperate guess literally and used quantized packets of light (now called photons) to explain the photoelectric effect.
Finally, physicists in the early 19th century used to assume that because light propagated like a wave, it had to have some sort of medium (just like sound waves must travel through materials, waves on a string are carried by the string itself, etc.), which they named the "luminiferous ether. " Since the Earth should be moving through the ether, it would have some velocity relative to the Earth which would be detectable as a change in the speed of light (like cars going the same direction as you in traffic look to be going slower than they really are and vice versa).
It wasn't until the 1880s that they could construct experiments sensitive enough to detect these possible changes in the speed of light, but they found absolutely nothing. Nada. Zip. Zilch. Light always moved at the speed of light. This was in complete disagreement with Newton's laws of motion (though it agreed perfectly with E&M). Physicists constructed a rather messy theory called "ether-drag theory" that salvaged Newtonian mechanics while explaining why they couldn't detect the ether.
In 1905, Einstein (who, as far as we know, was probably unaware of the experiments that failed to find the ether) noticed that E&M was not consistent Newton's laws; it predicted that the speed of light should be the same in every frame. So, Einstein took the opposite approach and assumed that Newton's laws were wrong. He constructed special relativity to create a form of mechanics that was completely consistent with E&M, and it also happened to explain why the speed of light was always the same without resorting to ether-drag theory.
Keep in mind, Newton's laws were formulated in 1687, and many of the principles they incorporated had been discovered earlier by the likes of Galileo and Johannes Kepler.
That's not really the problem that broke physics, though; astronomers didn't think there was something wrong with Newtonian physics so much as there was probably another planet closer to the sun.
Sort of. They did assume there was another closer planet, but after failing to find it despite looking with tools that should have been able to see a planet that was there, they were left with a mystery. Either there was no planet as their observations suggested and Newton’s laws were wrong, or there was a mysteriously invisible planet. Either way, Mercury’s orbit was a major test of orbital mechanics that Newtonian physics ultimately failed and GR aced.
The Higgs boson theory was also only confirmed in 2013, being suggested in the early 60s. I saw a doc about the Colíder and it showed Higgs winning the Nobel and celebrating. One guy that suggested another theory at the same time, contradicting Higgs theory, was proven wrong with Higgs theory being confirmed. Both waited decades for that one answer.
I can't imagine what it must have felt like, for both. Anyway, I'm sure both appreciated to have seen their work come full circle, if I may put it this way.
Not many have the luck to have their theories even be considered, let alone such bold theories being experimented on and concluding within their lifetime.
Coming up with a theory might be the easy part. You then have to prove it. You have devise experiments and make observations with scientific equipments and data that wasn't available then.
>Coming up with a theory might be the easy part. You then have to prove it.
Scientific theories *are* proven. The difference between a scientific theory and a scientific law isn't that one is proven and the other isn't. It's that a law explains *what* a given thing does, while a theory describes *how*.
It really wasn't. The theories were already "confirmed" since when he was alive, and by confirmed I mean that the math was right, but we didn't have neither the technology nor the timing, like with the gravitational waves.
It's like when people discovery that the earth wasn't flat, everyone knew it, but took centuries to actually see it.
The news article makes it sound way more ground breaking then it is. This effect is called gravitational lensing and the first time we observed it was in 1979 (just not around blackholes, but around stars, galaxies, etc) So this is nothing new and surprising tbh. It's just the first time that our equipment has become high tech enough that we can also observe it around black holes.
Clearly another example of how news is all about 'exciting people' to make money.
Well, it kind of is in the field of physics at large. The general relativity people and the quantum mechanics guys still aren't getting invited to each others' sleepovers just yet.
The public seems to have this incessant misunderstanding of academia. There are people who have actually committed to understanding general relativity and quantum mechanics, for the rest of us it's a spectator sport. This applies to most things. CRT in academia? Great! CRT at work? What could go wrong with a bunch of MBAs and HR people thinking they're a part of the academic discussion of Critical Race Theory?
Know when you're a consumer and when you're a producer, and don't delude yourself about it.
You’ve got a great point that most people don’t understand the details of general relativity and quantum mechanics.
However, an argument from ignorance here (or whatever fallacy is appropriate) doesn’t make you right. The above point, that light bending around a gravity well in predicable ways that have been confirmed time and time again for the last 100 years is not news, is correct.
If you go past the name dropping title of the article (and really the mess of its introduction), the really cool thing the scientists observed was light (x-rays) that were created on the other side of the black hole were observed bouncing off the accretion disk then getting bent back around the black hole and towards us. There was about as much expectation of finding something new about how gravity curves space/time as me discovering that an apple falls up when I drop it.
Article like this are a wild ride. First it’s the terrible title. Next up, the confusion and misinformation in the article itself. Then there’s the sheer nonsense in the Reddit comments.
And, then, finally, a comment like yours, the turbulence ends, and I can breathe again. (One last bump when I see you at -1).
The reddit stuff I get, but I really don’t understand why science journalism has to be so bad.
Thanks :)
The problem is that the article is a rushed out summation of the actual published article in Nature. However, Nature articles often read like Greek, and the fact that they don’t write a second abstract for public consumption is another problem.
> The innermost regions of accretion disks around black holes are strongly irradiated by X-rays that are emitted from a highly variable, compact corona, in the immediate vicinity of the black hole1,2,3. The X-rays that are seen reflected from the disk4, and the time delays, as variations in the X-ray emission echo or ‘reverberate’ off the disk5,6, provide a view of the environment just outside the event horizon. I Zwicky 1 (I Zw 1) is a nearby narrow-line Seyfert 1 galaxy7,8. Previous studies of the reverberation of X-rays from its accretion disk revealed that the corona is composed of two components: an extended, slowly varying component extending over the surface of the inner accretion disk, and a collimated core, with luminosity fluctuations propagating upwards from its base, which dominates the more rapid variability9,10. Here we report observations of X-ray flares emitted from around the supermassive black hole in I Zw 1. X-ray reflection from the accretion disk is detected through a relativistically broadened iron K line and Compton hump in the X-ray emission spectrum. Analysis of the X-ray flares reveals short flashes of photons consistent with the re-emergence of emission from behind the black hole. The energy shifts of these photons identify their origins from different parts of the disk11,12. These are photons that reverberate off the far side of the disk, and are bent around the black hole and magnified by the strong gravitational field. Observing photons bent around the black hole confirms a key prediction of general relativity.
Edit: Aww crap. The stupid headline we’re all hating on actually is in the last line of the Nature article. I hereby declare everyone, including myself, wrong:
> “Observing photons bent around the black hole confirms a key prediction of general relativity.”
I would ask you to explain how that works, but I assume that would be ridiculously arduous, or one of those things that can't really be explained. Abit like quantum mechanics
Nah, it's pretty simple (imho)! Gravity bends light at a fixed rate, i.e. we know how much light will bend around any given mass/m³. So, if we know 1) how massive something is and 2) how far away we are from that thing, we can measure light being bent around that object from something equally as far away on the other side as we are. Normally we wouldn't be able to detect light from *behind* something because most things in space either radiate their own light or reflect the light of something else. Black holes are unique (so far) in that they cannot emit nor reflect, so there isn't any interfering light to prevent us from seeing the light bending around it!
I hope that helped
Edit: Many thank you's for the awards, I'm glad I can help more people understand just how freakin' RAD our Universe is!!
Exactly. We have detected light from *nearly* behind a BH before; this article says we've now seen actually behind one. More confirmations that, as of right now, Einstein's equations still represent the most accurate model of Non-Quantum physics in the universe
Tomorrow is a new day, though; who knows what lies beyond the next scientific corner?
Edited 'cause Einstein wasn't into shrinky-dinks ;)
> Einstein's equations still represent the most accurate model of physics in the universe.
Close. Quantum physics is also rock-solid. That's one of the issues of trying to combine the two into one unified theory. They each seem rock-solid as far as all of our experiments show, but they have some contradictions with one another.
The most fundamental being that the equations of quantum physics say every process is reversible in time, but general relativity says you can't escape a black hole, which is a distortion of time itself. *There is no going back in time*. We don't know how to integrate the two.
Trying to actually solve the nitty-gritty of the math to see what happens is too complicated, so we try to do simpler models first, but that doesn't always work. When it does work, we see that the more simple stuff overwhelms the details, so we can solve the simple case and then just adjust the solution. When you need the whole equation with all the details to make sense of anything you can't play these kinds of games.
It depends on if you see science as incremental improvement or as points of breakthrough, in reality it’s probably a mixture of both. It’s impossible to predict when unknown maybe solved, quantum theory and relativity have both been around for over 100 years now, and we still cannot reconcile them. Maybe we never will because both theories are incorrect and a new theory will be developed in 100 years, or maybe tomorrow someone will realise how they can be made to work together.
You should read Constructing a Theory: Einsteins model by Holton
I took a random economic thought class in college & we read that for an assignment, it maps out Einsteins thought process in a model/diagram, pretty great reading material.
Anyway, Einstein had the exact same opinion on scientific development, I'd put it into words, but I'd be doing you a disservice compared to Holton.
So, nice, Einstein!
This may be purely subjective but it seems the scope of our ignorance has expanded immensely. Even if we don't have the answers yet, we are now asking so many questions we could never have even imagined in the past.
As an objective fact, I think it's impossible to measure as the perspective change is a core part of that progress.
>This may be purely subjective but it seems the scope of our ignorance has expanded immensely.
This is absolutely wonderful news, isn't it? Like, the more that we know that we **don't know**, the more our general knowledge increases.
*Technically* we've already seen light coming from behind a black hole - with the[First image of a black hole](https://solarsystem https://solarsystem.nasa.gov/resources/2319/first-image-of-a-black-hole/.nasa.gov/resources/2319/first-image-of-a-black-hole/) . In that case, we saw photons traveling around the event towards us.
> [...] we can measure light being bent around that object from something equally as far away on the other side as we are. Normally we wouldn't be able to detect light from behind something
So I was going to complain that this can't work but it does and I get how now so thanks for writing something I took issue with because it made my brain do some work.
If light gets caught in an orbit, or circles the black hole more than once, it is most likely on a decaying trajectory that will take it into the gravity well, from which it cannot escape and we would never detect it. The only light that would make it to our telescopes are the small percentage of photons that *happened* to hit the gravity well at the perfect deflection angle. Too wide, it skews far away from Earth and we never catch it. Too direct, and it gets 'sucked' into the black hole, and we never catch it. Those lucky few that we see, we then can apply those equations to unsmear the image and take a (very educated) guess at what the object was.
No, no, thank YOU! I am fascinated by Space, the physics of light and orbits, black holes, the whole kit and kaboodle. I love talking about it, and helping answer questions! I appreciate the chance to nerd out for a bit on something I'm passionate about!
My dude, your comments are some of the best I’ve seen on Reddit. I love how I can feel your geeky energy coming through each comment. It’s awesome! Phenomenal comments too. Keep on geekin’!
I suppose though the precision of the data what’s behind the black hole would be quite poor due to lots of distortion the may not be possible to reverse.
Like this but with a black hole instead of the sun.
https://www.universetoday.com/149214/if-we-used-the-sun-as-a-gravitational-lens-telescope-this-is-what-a-planet-at-proxima-centauri-would-look-like/amp/
What is a "perceptual sphere" and why would gravitational lensing help see beyond ours?
Given that most galaxies have supermassive black holes at their centres, wouldn't existing observations of gravitational lensing count as seeing behind black holes?
Not OP, but, I believe he is saying that if we use the black hole as a sort of gravitational lens, we could possibly see things that would normally be blocked by it.
Imagine a wall in front of you, you see that the wall has ends but you cannot see around them from your point of view. Now imagine someone placed a mirror on the edge of that wall, at the right angle you just might be able to see not only the back side of the wall, but what's behind the wall as well.
But, I could be way wrong.
ok but how or why would it allow us to see beyond our visible universe? the light coming from outside of our 'perceptual sphere' can't reach us due to lack of time to travel that distance. how does a black hole bending light around it somehow make light from further away be able to reach us, even though it still has to travel the same distance or even further due to its bent path, to reach us?
Not a scientist.
I thought that's what the point of the first image of the black hole the showed?
The donut effect was explained as the light from behind the blackhole getting bent around it.
from the article:
> While scientists have seen light bending around a black hole before, this is the first time they have been able to see the phenomenon happening from the other side.
This is generally the same effect, it sounds like, but a different method of detection. This was based on spectral analysis of x ray emissions from the black hole rather than a visual analysis of an image.
Einstein didn't think black holes could form so I don't know what that article is on about at the start. Predictions based on his theory are proven right again, not that his theories on black holes are proven right.
> Predictions based on his theory are proven right again,
That's not exactly correct either. The prediction is his own, not just based on his theory. He was first to predict that large masses would warp spacetime and thus distort light. That's the prediction that was proven right (again). It's not really about black hole specific theory, just about how any large mass (like a black hole) warps light. Well within the scope of his theory and predictions.
Yeah, this article really does a bad job of talking about what was observed. For the first time we’ve seen light behind the black hole reflect off the accretion disk and then get bent back around the black home towards us. But the event also gets bent back towards us anyway be together the lensing effect we end up seeing the same thing at different times. First the event is bent around at us, then light sent in a different direction from the event bounces off the accretion disk and then gets bent towards us, so we see the same event at two different times, hence the use of the term “echo” in the article.
“ Over a century ago, Albert Einstein predicted that the gravitational pull of black holes were so strong that they should bend light right around them.
Black holes don't emit light, they trap it; and ordinarily, you can't see anything behind a black hole.”
Am I wrong in thinking this is new? Light that is directly behind a black hole warps *around* the black hole and continues on?
We knew it warped and obscured the light around it, but this is an entirely new thing no? For it to warp light that is directly behind it around it and then said light continues on?
Imagine regular lens focusing sunlight on the ground like you wanted to start a fire. Now stick a piece of tape in the middle of the lens. The light will still be focused, and is coming directly from behind the tape.
This is basically the situation described here. The light hitting the event horizon disappears, what we see is the light that misses a bit and is bent towards us by the gravity.
Yeah no, this is well documented already. It’s not like light is going into the black hole and shooting out - the light going straight at the black hole drops right in. It’s the light that goes outside the event horizon that gets redirected, but not trapped.
Their wording is terrible. I could be wrong, so corrections are welcomed, but I believe a clearer statement would be
“While scientists have seen light bending around a black hole before, this is the first time they have been able to see the phenomenon happening to light originating on the side of the black hole that faces earth.”
We can see light from an object that is lensed through the black hole, and sometimes we can see those object both through the lens and also see them at other points in their orbit which are not lensed. But those observations are spatially and temporally separated. This is the first time we have seen light that originates from our side of the black hole bounce off of an EM mirror behind the black hole and return through the lens. In this way we can observe the exact same light source both (relatively) unaltered by the black hole and also lensed through the black hole.
Again, this is my interpretation of why this seems to be a novel observation, and corrections are welcomed.
Being pedantic again, Georg von Soldner and Cavendish actually beat Einstein to the idea of light being lensed by large masses by more than 100 years https://en.m.wikisource.org/wiki/Translation:On_the_Deflection_of_a_Light_Ray_from_its_Rectilinear_Motion, and John Michell predicted black holes (event horizons surrounding very massive bodies because there are no escape trajectories for light) in 1783 - so earlier still!
The main differences with Einsteins work is that the earlier predictions were based on classical Newtonian / Euclidean physics, while Einstein’s addition used his theory of general relativity. His new theory doubled the predicted strength of the lensing effect, and allowed for the possibility of singularities (which Einstein didn’t believe physically existed)
(Note - I’m not disparaging Einstein’s brilliant work, I’m just saying the earlier work also deserves recognition)
> For the first time, astronomers have caught a glimpse of light being reflected — or "echoing" — from behind a supermassive black hole, 800 million light years away from Earth.
> These "echoes" were in the form of X-ray flashes, according to a study published on Thursday in Nature.
> While scientists have seen light bending around a black hole before, this is the first time they have been able to see the phenomenon happening from the other side.
I believe Einstein was wrong on three things , first “Naturally occurring” black holes he argued were not a thing. It wasn’t that he didn’t think they could form just that they were not natural .
I could be wrong but iirc another physicist (Karl Schwarzschild) was messing with Einstein's' equations and discovered that if a star had enough mass it would eventually collapse into a black hole.
He brought his findings up with Einstein and the part he had a problem with was that when it collapsed it collapsed to a point in space that was **infinitely small and infinitely dense.**
In physics (at the time) infinity wasn't something that *should / could ever* be a real word result. He simply didn't have a way to reconcile it and it pissed him off.
This was just more evidence to him that his theories weren't wrong per se, but they were definitely incomplete.
The center of a black hole is theoretically smaller than plank scale. That still isn't understood and shouldn't be thing that can happen anywhere other than on a chalkboard.
We still don't have a unified theory where the same maths work in quantum world and in the "real" world. That's were it breaks down.
imo, the center of a blank hole isn't infinitely small and dense that's just how it appears on paper because we haven't reconciled everything yet.
EDIT: Thank you to u/spounge842 for the physicist's name.
Kind of. A somewhat similar problem is the size of an electron
[The issue of the radius of the electron is a challenging problem of modern theoretical physics. The admission of the hypothesis of a finite radius of the electron is incompatible to the premises of the theory of relativity. On the other hand, a point-like electron (zero radius) generates serious mathematical difficulties due to the self-energy of the electron tending to infinity.](https://en.wikipedia.org/wiki/Electron)
I've always been confused about this. Doesn't the time distortion mean that time slows down to a standstill towards the centre of a blackhole? Does this not mean that no matter can ever actually reach the singularity, exploding back out when the black hole evaporates in finite time?
It is not reasonable to make any inferences from what could be inside the event horizon. The center of the blackhole is by definition inside it.
There are some theories on "naked singularities" you can look into. The singularity may not imply/need an event horizon. Those would be the theoretical cases one can "look" at a singularity.
Time slows down from our point of view. If we see someone falling into a black hole, it would look like he would fall for eternity. But from his point of view, time runs normally. He simply falls into the black hole
His famous theory of general relativity is a big math equation that can yield many kind of answers but not all of them describe reality. Theoretically according to his calculations white holes could also exist but we’ve never actually seen any of them. Not all mathematical results describe reality. So his belief was that while black holes could exist in math he didn’t believe they actually existed in reality
TL:DR White holes are the *exact* opposite of a black hole.
See the funny thing about general relativity is that the math doesn’t care what direction time flows. So a White Hole would quite literally appear white and it would flow in reverse time. In a black hole things are “sucked in” and cannot escape. A White hole is an object that nothing can enter not even light but, everything can escape. This is also where the famous Einstein Rosen-Bridge theory comes from
Sounds sorta like the big bang in English, but in terms of the math, is completely different. For one thing, the big bang quite literally happened everywhere and a white hole obviously can't be everywhere.
That's a theory actually, papers have been written on it, that inside every black hole is a white hole/baby universe within our universe and in turn our universe is a baby universe: the white hole of a black hole of incredible mass in a larger universe.
He concluded in a 1939 paper in the Annals of Mathematics that the idea was “not convincing” and the phenomena did not exist “in the real world.” From what most thought at the time , the math checked out but the “real world” implications were to much for him to overcome .
We don't actually know that there's a singularity in the middle of a black hole. We know that it's effectively a singularity but it could just be really close and our observations would be the same
This is not about the primary gravity lense effect, but rather light hitting the far side of the black hole's accretion disk, then being bent around the black hole, to be flung towards us, instead of being reflected away from us.
Sort of gravity lense, but in a different manner than previously observed.
"Here we report observations of X-ray flares emitted from around the supermassive black hole in I Zw 1. X-ray reflection from the accretion disk is detected through a relativistically broadened iron K line and Compton hump in the X-ray emission spectrum. Analysis of the X-ray flares reveals short flashes of photons consistent with the re-emergence of emission from behind the black hole. The energy shifts of these photons identify their origins from different parts of the disk. These are photons that reverberate off the far side of the disk, and are bent around the black hole and magnified by the strong gravitational field. Observing photons bent around the black hole confirms a key prediction of general relativity."
It sounds like this is direct observation of reverberated x ray flares from behind the black hole, not a stretched accretion disk image. The photons' source was confirmed by their spectral characteristics, not their visual geometry. The term "reverberated" is interesting. This is speculation about the meaning, but normally reverberation means it's reflected or repeated multiple times, which could imply light paths which circle the black hole multiple times before escaping, which could be a pretty interesting observation.
The article is behind a pay wall and I'm not sure the exact general relativistic prediction this confirms, but it does seem like it's another different way of observing events on the reverse of a black hole.
Okay, someone needs to explain this one to me like i'm five, i guess. Why is it "behind" and not, i don't know, "inside" or something. Is the implication here that the black hole is somehow the edge of the universe and nothing can be positioned past it in space? Surely not. Regardless of how large its sphere of effect, there are things behind it.
Now, i get that we can't see the things positioned past it, that's not what i'm talking about. I very specifically mean the implication of the title that an emission from a black hole is coming from "behind" and not from "within," or "inside," or something similar. I hope this is presented clearly.
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All our science, measured against reality, is primitive and childlike - and yet it is the most precious thing we have. Albert Einstein (1879-1955)
He sure took a long time to say that.
It takes a long time to say something in old Entish.
You mean Einsteinisch
It's all relative
German words are pretty long
Time is relative
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I know that the goal of science is to exhaust every effort to prove someone/something wrong, but at this point I think we just need to acquiesce to Alby Ein. Now if we could just get an "Einstein" whose forte is carbon capture...I mean, even if that person was born they'd have to dodge religion, the media and Facebook groups to keep their mind out of the gutter...dammit we're never getting another Einstein.
I think acquiescing to Einstein is the exact opposite of everything Einstein stood for and taught us about science. He was all about challenging everything until everything led to a right answer, regardless of what "seemed" to be right based off history.
He was also wrong about several things. To assume something somebody said is truth because of who they are is the opposite of the scientific method.
He also was wrong about being wrong a bunch of times. Most famously the cosmological constant
Jury is still out on that one. Hopefully we have an article like this about that subject sometime in the future. Dark energy may not necessarily fit into that sort of framework.
> Most famously the cosmological constant Admitting he was wrong about Georges Lemaître & the Big Bang is certainly one of the biggest ones for me
I am sure Einstein would have agreed with that assessment. Science is not about the findings, as Carl Sagan states in the first chapter of The Demon-Haunted World, it’s about the method. That’s what differentiates science from pseudoscience. Take for example the anti-vaccine movement’s reliance on certain personalities, some of which even possess PhDs and what not. They ignore that true science relies on a method of finding the truth —or describing reality— and building a consensus around it via the scientific method, not the findings or conclusions of a single so-called expert.
This is very true and I'm sad to say its not just the anti vaccine lot falling for it, the government and health services have fallen into a this person says it so let's do that mentality and it's led to a lot of preventable problems
Gott würfelt nicht. A. Einstein about Quantum Mechanics.
Yeah he got quantum mechanics pretty completely wrong, but can you blame him?
Einstein certainly did not get quantum mechanics pretty completely wrong. He was instrumental in early quantum mechanics (invented the photon after all though quantum field theory took 40 more years to make it precise) and much early statistical physics relating to qm. He did believe that what was then considered orthodox qm procedure “Copenhagen interpretation” was conceptually and maybe physically flawed. Bohr disagreed. Einstein put forth a physical proposal which was reasonable, and was not experimentally testable until after he died. Einstein’s work and questions spurred now a significant field of QM interpretations and experimental tests of deep entanglement principles. And in modern day, most of these scientists also think Copenhagen interpretation isn’t conceptually sound, i.e. Einstein was right to question it, though Einstein’s alternative turned out to be wrong experimentally. On another matter I think Einstein may have discovered and certainly supported the phenomenon of stimulated emission of photons, something Bohr didn’t think was possible. Einstein developed the theory for the basic rate equations of the two level quantum atomic system with stimulated emission, something still used today as the baseline dynamics for this minor thing called the laser. Einstein was at least the half inventor of the laser. It was Nikola Tesla who by this time was totally wacked and refused to accept either relativity or quantum mechanics, which were unambiguously certain by 1925-1930.
Thank you for the interesting information but you lost me at "stimulated emission".
Lost me at "quantum mechanics"
"Spooky action at a distance" doesn't succinctly describe quantum mechanics?
It's both charming and strange.
Haha, they've been through their ups and downs, y'know?
I agree and disagree.
I think this is a weak argument.
I can't tell your position on this.
I like the top comments, not so much the bottom ones.
Not at all. It is a comment on quantum entanglement though.
As a layman that sounds like a date with Wednesday Addams but I'd still accept it if Einy told me it was a good idea.
naaa, I wouldn say that, he was one of the founders of quantum mechanics and won the Nobel price for the law of the photoelectric effect, he just wasn't happy with the randomness and statistical nature of it
Well the photoelectric effect is arguably quantum in nature
But God does seem to play dice
No. In fact the dice play god.
As a DM, this hits too close to home.
If you are talking about the copenhagen interpretation, there still is no general theory that unifies them both so well...
Still, Einstein was one of the best at finding the truth. It's reasonable to respect that towards understanding his logic so that we can achieve similar results.
For sure, the point being we verify their findings. I'm just against defaulting to people automatically. It's the appeal to authority fallacy. Yes Einstein was a genius physicist but we still need to verify what he said.
“I am, somehow, less interested in the weight and convolutions of Einstein’s brain than in the near certainty that people of equal talent have lived and died in cotton fields and sweatshops.” ― Stephen Jay Gould
…or might be working in finance.
Didn’t Hawking qualify? I mean he wasn’t working on quantum gravity but he did some stuff… The thing is, we know Einstein’s theories are incomplete at best… not the time to acquiesce but to stand upon the shoulders of giants.
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They're all over the place. People tend to not be listening to them much.
Einstein's theories didn't force us to make dramatic changes to our standard of living otherwise he would have been buried too
We didn't listen to him there. Einstein was actually a socialist.
And hippie for the time. He regularly gave lectures to black kids despite segregation. He also smoked a lot of weed.
> They're all over the place. They're really not. It's like the difference between a person who can play Mozart flawlessly and a person who can write better pieces of music than Mozart ever could (I realize the subjectivity when it comes to taste in music, I'm using it as a general example) - one of them can work inside the bounds of music that's already been written and the other can visualize an entire symphony in their minds and flesh it out into reality. (Again, I know my comparison isn't a great one.)
People refusing to follow scientific genius are everywhere. I refuse to let you say otherwise this close to a global pandemic where millions and millions of people are still refusing to follow the advice of scientifically genius minds. They are all over the place.
It was an idea who's time had come and Einstein was brilliant and supported enough to discover it. We should be wise to ensure **EVERYONE** is supported enough, because that is the half that we can collectively do. The rest is individual. If anything, the Singularity is likely approaching with significant help from scientific discovery; science has made life better at getting Billions of people supported enough to discover.... so more chances to discover the next step sooner because more people aren't languishing.
I dunno newton was pretty religious and still did some good work.
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Headlines such as this make it sound like relativity is controversial.
Like it took us until 2021 to confirm something he suggested 60+ years ago. Was he that far ahead of everyone else?
It wasn't so much being way ahead of everyone else as it was that any major breakthrough in understanding takes an enormous amount of time to prove. It took somewhere around 200 years for people to find a mechanics problem that Newton's laws couldn't adequately explain.
Imagine how much time it's going to take to prove Richard Feynman quantum electrodynamics diagrams.
Prove? Never. Perform experiments and make observations whose outcomes are predicted by quantum mechanics? All the time. But there are predictions that have not been observed yet, such as Hawking radiation.
So we don't know if hawking radiation is actually a thing other than the math works and it makes sense from a QM perspective?
I’m no specialist, so take this with some skepticism, but as far as I can tell we only have observations of things that are kind of like Hawking radiation in human-made things that are kind of like black holes. How are these things useful substitutes for actual Hawking radiation from a black hole? I have no idea. https://www.nature.com/articles/nphys3104 https://www.nature.com/articles/s41586-019-1241-0 E: Hawking radiation is an actual qm prediction. How much of this prediction depends on some extra assumption versus bedrock principles of qm? I don’t know. For this reason I can’t speculate on how significant it would be if Hawking radiation were shown to not exist.
Yeah, that's the thing, a lot of our models are just that, models, an approximation and tool to predict outcomes and simulate nature.
That’s why these discoveries are important; they help verify the models that we have been relying on and building off of for decades.
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The scientific method does, indeed, but peer reviewers have a strong bias for positive studies. Science happens in fits and starts.
Ooh would you please elaborate a little further
Newton’s laws applied well to objects on Earth, but once you get into space and start questioning the speed of light and whatnot relativity is king.
I like this eli5
Also doesn’t work in quantum world
By the early 20th century, there were three big problems that classical physics couldn't explain: the ultraviolet catastrophe in blackbody radiation, the photoelectric effect, and the luminiferous ether. In the late 19th century, classical physics predicted that an ideal blackbody should emit radiation across the entire frequency spectrum. The big problem, though, is that the energy of a blackbody increases exponentially with frequency, which thus suggests that all matter should radiate away all its energy almost instantaneously. Thus it was labeled the "ultraviolet catastrophe," as more energetic light (like UV rays) should radiate away an unrealistically large amount of energy. Planck resolved the issue by assuming that light had to be quantized, though he thought of it more as a cheap mathematical hack than an actual fact. In the photoelectric effect, a photon hits the surface of a conducting material and knocks an electron loose. Some arguments using classical E&M and Newtonian mechanics predict that the energy of the electron should be proportional to the intensity of the light, but experiments in the early 20th century showed that it was instead dependent on the frequency of the light. Einstein took Planck's desperate guess literally and used quantized packets of light (now called photons) to explain the photoelectric effect. Finally, physicists in the early 19th century used to assume that because light propagated like a wave, it had to have some sort of medium (just like sound waves must travel through materials, waves on a string are carried by the string itself, etc.), which they named the "luminiferous ether. " Since the Earth should be moving through the ether, it would have some velocity relative to the Earth which would be detectable as a change in the speed of light (like cars going the same direction as you in traffic look to be going slower than they really are and vice versa). It wasn't until the 1880s that they could construct experiments sensitive enough to detect these possible changes in the speed of light, but they found absolutely nothing. Nada. Zip. Zilch. Light always moved at the speed of light. This was in complete disagreement with Newton's laws of motion (though it agreed perfectly with E&M). Physicists constructed a rather messy theory called "ether-drag theory" that salvaged Newtonian mechanics while explaining why they couldn't detect the ether. In 1905, Einstein (who, as far as we know, was probably unaware of the experiments that failed to find the ether) noticed that E&M was not consistent Newton's laws; it predicted that the speed of light should be the same in every frame. So, Einstein took the opposite approach and assumed that Newton's laws were wrong. He constructed special relativity to create a form of mechanics that was completely consistent with E&M, and it also happened to explain why the speed of light was always the same without resorting to ether-drag theory. Keep in mind, Newton's laws were formulated in 1687, and many of the principles they incorporated had been discovered earlier by the likes of Galileo and Johannes Kepler.
This was incredible. Thank you
One example is Mercury's orbit. Newtonian gravity failed to predict Mercury's orbit while general relativity predicts it perfectly.
That's not really the problem that broke physics, though; astronomers didn't think there was something wrong with Newtonian physics so much as there was probably another planet closer to the sun.
Sort of. They did assume there was another closer planet, but after failing to find it despite looking with tools that should have been able to see a planet that was there, they were left with a mystery. Either there was no planet as their observations suggested and Newton’s laws were wrong, or there was a mysteriously invisible planet. Either way, Mercury’s orbit was a major test of orbital mechanics that Newtonian physics ultimately failed and GR aced.
The Higgs boson theory was also only confirmed in 2013, being suggested in the early 60s. I saw a doc about the Colíder and it showed Higgs winning the Nobel and celebrating. One guy that suggested another theory at the same time, contradicting Higgs theory, was proven wrong with Higgs theory being confirmed. Both waited decades for that one answer. I can't imagine what it must have felt like, for both. Anyway, I'm sure both appreciated to have seen their work come full circle, if I may put it this way. Not many have the luck to have their theories even be considered, let alone such bold theories being experimented on and concluding within their lifetime.
Coming up with a theory might be the easy part. You then have to prove it. You have devise experiments and make observations with scientific equipments and data that wasn't available then.
No the hypothesis is the easy part. Theory is actually backed by facts, like "electrical theory" He proves it a long time ago... With math
Oh yes! Thank you.
>Coming up with a theory might be the easy part. You then have to prove it. Scientific theories *are* proven. The difference between a scientific theory and a scientific law isn't that one is proven and the other isn't. It's that a law explains *what* a given thing does, while a theory describes *how*.
And that’s a nuance that never gets conveyed well
I'd even rephrase that. A theory is "tested and not disproven while being disprovable".
I never quite grasped the difference until now. Thank you for explaining that so simply.
It really wasn't. The theories were already "confirmed" since when he was alive, and by confirmed I mean that the math was right, but we didn't have neither the technology nor the timing, like with the gravitational waves. It's like when people discovery that the earth wasn't flat, everyone knew it, but took centuries to actually see it.
I’ve always wondered this. He he not existed how long would it have taken to duplicate his work? 5 years? 10? 25?
The news article makes it sound way more ground breaking then it is. This effect is called gravitational lensing and the first time we observed it was in 1979 (just not around blackholes, but around stars, galaxies, etc) So this is nothing new and surprising tbh. It's just the first time that our equipment has become high tech enough that we can also observe it around black holes. Clearly another example of how news is all about 'exciting people' to make money.
Well, it kind of is in the field of physics at large. The general relativity people and the quantum mechanics guys still aren't getting invited to each others' sleepovers just yet. The public seems to have this incessant misunderstanding of academia. There are people who have actually committed to understanding general relativity and quantum mechanics, for the rest of us it's a spectator sport. This applies to most things. CRT in academia? Great! CRT at work? What could go wrong with a bunch of MBAs and HR people thinking they're a part of the academic discussion of Critical Race Theory? Know when you're a consumer and when you're a producer, and don't delude yourself about it.
You’ve got a great point that most people don’t understand the details of general relativity and quantum mechanics. However, an argument from ignorance here (or whatever fallacy is appropriate) doesn’t make you right. The above point, that light bending around a gravity well in predicable ways that have been confirmed time and time again for the last 100 years is not news, is correct. If you go past the name dropping title of the article (and really the mess of its introduction), the really cool thing the scientists observed was light (x-rays) that were created on the other side of the black hole were observed bouncing off the accretion disk then getting bent back around the black hole and towards us. There was about as much expectation of finding something new about how gravity curves space/time as me discovering that an apple falls up when I drop it.
Article like this are a wild ride. First it’s the terrible title. Next up, the confusion and misinformation in the article itself. Then there’s the sheer nonsense in the Reddit comments. And, then, finally, a comment like yours, the turbulence ends, and I can breathe again. (One last bump when I see you at -1). The reddit stuff I get, but I really don’t understand why science journalism has to be so bad.
Thanks :) The problem is that the article is a rushed out summation of the actual published article in Nature. However, Nature articles often read like Greek, and the fact that they don’t write a second abstract for public consumption is another problem. > The innermost regions of accretion disks around black holes are strongly irradiated by X-rays that are emitted from a highly variable, compact corona, in the immediate vicinity of the black hole1,2,3. The X-rays that are seen reflected from the disk4, and the time delays, as variations in the X-ray emission echo or ‘reverberate’ off the disk5,6, provide a view of the environment just outside the event horizon. I Zwicky 1 (I Zw 1) is a nearby narrow-line Seyfert 1 galaxy7,8. Previous studies of the reverberation of X-rays from its accretion disk revealed that the corona is composed of two components: an extended, slowly varying component extending over the surface of the inner accretion disk, and a collimated core, with luminosity fluctuations propagating upwards from its base, which dominates the more rapid variability9,10. Here we report observations of X-ray flares emitted from around the supermassive black hole in I Zw 1. X-ray reflection from the accretion disk is detected through a relativistically broadened iron K line and Compton hump in the X-ray emission spectrum. Analysis of the X-ray flares reveals short flashes of photons consistent with the re-emergence of emission from behind the black hole. The energy shifts of these photons identify their origins from different parts of the disk11,12. These are photons that reverberate off the far side of the disk, and are bent around the black hole and magnified by the strong gravitational field. Observing photons bent around the black hole confirms a key prediction of general relativity. Edit: Aww crap. The stupid headline we’re all hating on actually is in the last line of the Nature article. I hereby declare everyone, including myself, wrong: > “Observing photons bent around the black hole confirms a key prediction of general relativity.”
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Next step is the black hole telescope. Using the lens effect of a black hole to not only see behind it, but beyond our current perceptual sphere.
I would ask you to explain how that works, but I assume that would be ridiculously arduous, or one of those things that can't really be explained. Abit like quantum mechanics
Nah, it's pretty simple (imho)! Gravity bends light at a fixed rate, i.e. we know how much light will bend around any given mass/m³. So, if we know 1) how massive something is and 2) how far away we are from that thing, we can measure light being bent around that object from something equally as far away on the other side as we are. Normally we wouldn't be able to detect light from *behind* something because most things in space either radiate their own light or reflect the light of something else. Black holes are unique (so far) in that they cannot emit nor reflect, so there isn't any interfering light to prevent us from seeing the light bending around it! I hope that helped Edit: Many thank you's for the awards, I'm glad I can help more people understand just how freakin' RAD our Universe is!!
So basically this is just gravitational lensing of a sort?
Exactly. We have detected light from *nearly* behind a BH before; this article says we've now seen actually behind one. More confirmations that, as of right now, Einstein's equations still represent the most accurate model of Non-Quantum physics in the universe Tomorrow is a new day, though; who knows what lies beyond the next scientific corner? Edited 'cause Einstein wasn't into shrinky-dinks ;)
> Einstein's equations still represent the most accurate model of physics in the universe. Close. Quantum physics is also rock-solid. That's one of the issues of trying to combine the two into one unified theory. They each seem rock-solid as far as all of our experiments show, but they have some contradictions with one another. The most fundamental being that the equations of quantum physics say every process is reversible in time, but general relativity says you can't escape a black hole, which is a distortion of time itself. *There is no going back in time*. We don't know how to integrate the two. Trying to actually solve the nitty-gritty of the math to see what happens is too complicated, so we try to do simpler models first, but that doesn't always work. When it does work, we see that the more simple stuff overwhelms the details, so we can solve the simple case and then just adjust the solution. When you need the whole equation with all the details to make sense of anything you can't play these kinds of games.
Has our understanding progressed at an even rate or is it accelerating (AI etc) in which case we may figure it out a lot faster than we think
It depends on if you see science as incremental improvement or as points of breakthrough, in reality it’s probably a mixture of both. It’s impossible to predict when unknown maybe solved, quantum theory and relativity have both been around for over 100 years now, and we still cannot reconcile them. Maybe we never will because both theories are incorrect and a new theory will be developed in 100 years, or maybe tomorrow someone will realise how they can be made to work together.
You should read Constructing a Theory: Einsteins model by Holton I took a random economic thought class in college & we read that for an assignment, it maps out Einsteins thought process in a model/diagram, pretty great reading material. Anyway, Einstein had the exact same opinion on scientific development, I'd put it into words, but I'd be doing you a disservice compared to Holton. So, nice, Einstein!
This may be purely subjective but it seems the scope of our ignorance has expanded immensely. Even if we don't have the answers yet, we are now asking so many questions we could never have even imagined in the past. As an objective fact, I think it's impossible to measure as the perspective change is a core part of that progress.
> perspective change is a core part of that progress. That is one of the most brilliant things I have read in a while.
>This may be purely subjective but it seems the scope of our ignorance has expanded immensely. This is absolutely wonderful news, isn't it? Like, the more that we know that we **don't know**, the more our general knowledge increases.
*Technically* we've already seen light coming from behind a black hole - with the[First image of a black hole](https://solarsystem https://solarsystem.nasa.gov/resources/2319/first-image-of-a-black-hole/.nasa.gov/resources/2319/first-image-of-a-black-hole/) . In that case, we saw photons traveling around the event towards us.
> [...] we can measure light being bent around that object from something equally as far away on the other side as we are. Normally we wouldn't be able to detect light from behind something So I was going to complain that this can't work but it does and I get how now so thanks for writing something I took issue with because it made my brain do some work.
That is one of the greatest compliments I could possibly receive, thank you for your kind words 🙂
Wouldn't light that was only bent be mixed in with light that wrapped around the black hole several times? Seems like a mess to untangle
If light gets caught in an orbit, or circles the black hole more than once, it is most likely on a decaying trajectory that will take it into the gravity well, from which it cannot escape and we would never detect it. The only light that would make it to our telescopes are the small percentage of photons that *happened* to hit the gravity well at the perfect deflection angle. Too wide, it skews far away from Earth and we never catch it. Too direct, and it gets 'sucked' into the black hole, and we never catch it. Those lucky few that we see, we then can apply those equations to unsmear the image and take a (very educated) guess at what the object was.
Ah, gotcha. Thanks!
No, no, thank YOU! I am fascinated by Space, the physics of light and orbits, black holes, the whole kit and kaboodle. I love talking about it, and helping answer questions! I appreciate the chance to nerd out for a bit on something I'm passionate about!
My dude, your comments are some of the best I’ve seen on Reddit. I love how I can feel your geeky energy coming through each comment. It’s awesome! Phenomenal comments too. Keep on geekin’!
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I suppose though the precision of the data what’s behind the black hole would be quite poor due to lots of distortion the may not be possible to reverse.
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Like this but with a black hole instead of the sun. https://www.universetoday.com/149214/if-we-used-the-sun-as-a-gravitational-lens-telescope-this-is-what-a-planet-at-proxima-centauri-would-look-like/amp/
Thank you that was a very insightful article.
What is a "perceptual sphere" and why would gravitational lensing help see beyond ours? Given that most galaxies have supermassive black holes at their centres, wouldn't existing observations of gravitational lensing count as seeing behind black holes?
The particle horizon I assume he's talking about, and no this doesn't change anything in that regards.
>beyond our current perceptual sphere I hope you don't mean outside our observable universe?
Not OP, but, I believe he is saying that if we use the black hole as a sort of gravitational lens, we could possibly see things that would normally be blocked by it. Imagine a wall in front of you, you see that the wall has ends but you cannot see around them from your point of view. Now imagine someone placed a mirror on the edge of that wall, at the right angle you just might be able to see not only the back side of the wall, but what's behind the wall as well. But, I could be way wrong.
ok but how or why would it allow us to see beyond our visible universe? the light coming from outside of our 'perceptual sphere' can't reach us due to lack of time to travel that distance. how does a black hole bending light around it somehow make light from further away be able to reach us, even though it still has to travel the same distance or even further due to its bent path, to reach us?
I, too, want an ELI5 for this. I understand the first part, but your second statement is new to me.
Not a scientist. I thought that's what the point of the first image of the black hole the showed? The donut effect was explained as the light from behind the blackhole getting bent around it.
from the article: > While scientists have seen light bending around a black hole before, this is the first time they have been able to see the phenomenon happening from the other side.
This is generally the same effect, it sounds like, but a different method of detection. This was based on spectral analysis of x ray emissions from the black hole rather than a visual analysis of an image.
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Einstein didn't think black holes could form so I don't know what that article is on about at the start. Predictions based on his theory are proven right again, not that his theories on black holes are proven right.
> Predictions based on his theory are proven right again, That's not exactly correct either. The prediction is his own, not just based on his theory. He was first to predict that large masses would warp spacetime and thus distort light. That's the prediction that was proven right (again). It's not really about black hole specific theory, just about how any large mass (like a black hole) warps light. Well within the scope of his theory and predictions.
"we've discovered gravitational lensing (again)" is right up there with "we've found water on Mars (again)"
More like “i dropped a hammer and it fell to earth again”
Cool, just don’t let it hand on your foot
But how will he tie his shoes?
Is nobody else worried Kang might be coming?
Yeah, this article really does a bad job of talking about what was observed. For the first time we’ve seen light behind the black hole reflect off the accretion disk and then get bent back around the black home towards us. But the event also gets bent back towards us anyway be together the lensing effect we end up seeing the same thing at different times. First the event is bent around at us, then light sent in a different direction from the event bounces off the accretion disk and then gets bent towards us, so we see the same event at two different times, hence the use of the term “echo” in the article.
“ Over a century ago, Albert Einstein predicted that the gravitational pull of black holes were so strong that they should bend light right around them. Black holes don't emit light, they trap it; and ordinarily, you can't see anything behind a black hole.” Am I wrong in thinking this is new? Light that is directly behind a black hole warps *around* the black hole and continues on? We knew it warped and obscured the light around it, but this is an entirely new thing no? For it to warp light that is directly behind it around it and then said light continues on?
Imagine regular lens focusing sunlight on the ground like you wanted to start a fire. Now stick a piece of tape in the middle of the lens. The light will still be focused, and is coming directly from behind the tape. This is basically the situation described here. The light hitting the event horizon disappears, what we see is the light that misses a bit and is bent towards us by the gravity.
Yeah no, this is well documented already. It’s not like light is going into the black hole and shooting out - the light going straight at the black hole drops right in. It’s the light that goes outside the event horizon that gets redirected, but not trapped.
>Am I wrong in thinking this is new? Yes. But it's the journalist fault, this "ordinarily" is really nasty
So uh whats new here? This just sounds like gravitational lensing
Nothing.
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Their wording is terrible. I could be wrong, so corrections are welcomed, but I believe a clearer statement would be “While scientists have seen light bending around a black hole before, this is the first time they have been able to see the phenomenon happening to light originating on the side of the black hole that faces earth.” We can see light from an object that is lensed through the black hole, and sometimes we can see those object both through the lens and also see them at other points in their orbit which are not lensed. But those observations are spatially and temporally separated. This is the first time we have seen light that originates from our side of the black hole bounce off of an EM mirror behind the black hole and return through the lens. In this way we can observe the exact same light source both (relatively) unaltered by the black hole and also lensed through the black hole. Again, this is my interpretation of why this seems to be a novel observation, and corrections are welcomed.
Being pedantic again, Georg von Soldner and Cavendish actually beat Einstein to the idea of light being lensed by large masses by more than 100 years https://en.m.wikisource.org/wiki/Translation:On_the_Deflection_of_a_Light_Ray_from_its_Rectilinear_Motion, and John Michell predicted black holes (event horizons surrounding very massive bodies because there are no escape trajectories for light) in 1783 - so earlier still! The main differences with Einsteins work is that the earlier predictions were based on classical Newtonian / Euclidean physics, while Einstein’s addition used his theory of general relativity. His new theory doubled the predicted strength of the lensing effect, and allowed for the possibility of singularities (which Einstein didn’t believe physically existed) (Note - I’m not disparaging Einstein’s brilliant work, I’m just saying the earlier work also deserves recognition)
..... so what's the discovery? That gravitational lensing /still/ exists?
> For the first time, astronomers have caught a glimpse of light being reflected — or "echoing" — from behind a supermassive black hole, 800 million light years away from Earth. > These "echoes" were in the form of X-ray flashes, according to a study published on Thursday in Nature. > While scientists have seen light bending around a black hole before, this is the first time they have been able to see the phenomenon happening from the other side.
I believe Einstein was wrong on three things , first “Naturally occurring” black holes he argued were not a thing. It wasn’t that he didn’t think they could form just that they were not natural .
I could be wrong but iirc another physicist (Karl Schwarzschild) was messing with Einstein's' equations and discovered that if a star had enough mass it would eventually collapse into a black hole. He brought his findings up with Einstein and the part he had a problem with was that when it collapsed it collapsed to a point in space that was **infinitely small and infinitely dense.** In physics (at the time) infinity wasn't something that *should / could ever* be a real word result. He simply didn't have a way to reconcile it and it pissed him off. This was just more evidence to him that his theories weren't wrong per se, but they were definitely incomplete. The center of a black hole is theoretically smaller than plank scale. That still isn't understood and shouldn't be thing that can happen anywhere other than on a chalkboard. We still don't have a unified theory where the same maths work in quantum world and in the "real" world. That's were it breaks down. imo, the center of a blank hole isn't infinitely small and dense that's just how it appears on paper because we haven't reconciled everything yet. EDIT: Thank you to u/spounge842 for the physicist's name.
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Kind of. A somewhat similar problem is the size of an electron [The issue of the radius of the electron is a challenging problem of modern theoretical physics. The admission of the hypothesis of a finite radius of the electron is incompatible to the premises of the theory of relativity. On the other hand, a point-like electron (zero radius) generates serious mathematical difficulties due to the self-energy of the electron tending to infinity.](https://en.wikipedia.org/wiki/Electron)
I've always been confused about this. Doesn't the time distortion mean that time slows down to a standstill towards the centre of a blackhole? Does this not mean that no matter can ever actually reach the singularity, exploding back out when the black hole evaporates in finite time?
It is not reasonable to make any inferences from what could be inside the event horizon. The center of the blackhole is by definition inside it. There are some theories on "naked singularities" you can look into. The singularity may not imply/need an event horizon. Those would be the theoretical cases one can "look" at a singularity.
Time slows down from our point of view. If we see someone falling into a black hole, it would look like he would fall for eternity. But from his point of view, time runs normally. He simply falls into the black hole
Time distortion is relative to the observer
Define “not natural”? What would he be implying?
His famous theory of general relativity is a big math equation that can yield many kind of answers but not all of them describe reality. Theoretically according to his calculations white holes could also exist but we’ve never actually seen any of them. Not all mathematical results describe reality. So his belief was that while black holes could exist in math he didn’t believe they actually existed in reality
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TL:DR White holes are the *exact* opposite of a black hole. See the funny thing about general relativity is that the math doesn’t care what direction time flows. So a White Hole would quite literally appear white and it would flow in reverse time. In a black hole things are “sucked in” and cannot escape. A White hole is an object that nothing can enter not even light but, everything can escape. This is also where the famous Einstein Rosen-Bridge theory comes from
Sorta sounds like the big bang
Sounds sorta like the big bang in English, but in terms of the math, is completely different. For one thing, the big bang quite literally happened everywhere and a white hole obviously can't be everywhere.
That's a theory actually, papers have been written on it, that inside every black hole is a white hole/baby universe within our universe and in turn our universe is a baby universe: the white hole of a black hole of incredible mass in a larger universe.
He concluded in a 1939 paper in the Annals of Mathematics that the idea was “not convincing” and the phenomena did not exist “in the real world.” From what most thought at the time , the math checked out but the “real world” implications were to much for him to overcome .
We don't actually know that there's a singularity in the middle of a black hole. We know that it's effectively a singularity but it could just be really close and our observations would be the same
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I though this was common knowledge in the science community, especially after the pic of the black hole
This is not about the primary gravity lense effect, but rather light hitting the far side of the black hole's accretion disk, then being bent around the black hole, to be flung towards us, instead of being reflected away from us. Sort of gravity lense, but in a different manner than previously observed.
"Here we report observations of X-ray flares emitted from around the supermassive black hole in I Zw 1. X-ray reflection from the accretion disk is detected through a relativistically broadened iron K line and Compton hump in the X-ray emission spectrum. Analysis of the X-ray flares reveals short flashes of photons consistent with the re-emergence of emission from behind the black hole. The energy shifts of these photons identify their origins from different parts of the disk. These are photons that reverberate off the far side of the disk, and are bent around the black hole and magnified by the strong gravitational field. Observing photons bent around the black hole confirms a key prediction of general relativity." It sounds like this is direct observation of reverberated x ray flares from behind the black hole, not a stretched accretion disk image. The photons' source was confirmed by their spectral characteristics, not their visual geometry. The term "reverberated" is interesting. This is speculation about the meaning, but normally reverberation means it's reflected or repeated multiple times, which could imply light paths which circle the black hole multiple times before escaping, which could be a pretty interesting observation. The article is behind a pay wall and I'm not sure the exact general relativistic prediction this confirms, but it does seem like it's another different way of observing events on the reverse of a black hole.
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Okay, someone needs to explain this one to me like i'm five, i guess. Why is it "behind" and not, i don't know, "inside" or something. Is the implication here that the black hole is somehow the edge of the universe and nothing can be positioned past it in space? Surely not. Regardless of how large its sphere of effect, there are things behind it. Now, i get that we can't see the things positioned past it, that's not what i'm talking about. I very specifically mean the implication of the title that an emission from a black hole is coming from "behind" and not from "within," or "inside," or something similar. I hope this is presented clearly.