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okay so have you seen any of the headlines yet no Stanford astrophysicist report first detection of light from behind a black hole for the first time light has been directly observed from behind a supermassive black hole so you haven't seen this are you intrigued yes me or Earth black hole behind also it's not like showing it's weird interesting for a couple reasons one why would the light from behind the black hole make it around second reason is that the fact that we can distinguish the light coming from in front of and coming from behind the black hole how would they possibly know that the light is coming from behind the black hole and not in front of it any guesses as to how we do that can we see the shape of the
black hole no so imagine taking a car headlight into the distance would you be able to see the shape of the headlight no you wouldn't be able to tell like a square a Ford headlight from like around I don't know old 1930s headlight you wouldn't be able to tell all you'd be seeing is a little point right so how could you possibly see the shape or structure of anything in this black hole when it's not in the distance of a few miles away when it's 800 million light years away there's a like no x-rays oh it's only extra it's only x-rays so another really cool thing about this is that we would not have been able to do this kind of astronomy until a few decades ago because we didn't have x-ray
telescopes what astronomers saw was they're like okay so we see these x-ray bursts coming from the black hole they're like cool like we want to study those and then they saw there are these other bursts coming a little bit later that are a little bit fainter and a little bit different color so some of the light is coming from in front of and some is coming from behind so it's going to take longer for the light that's coming from behind the black hole to get to us so there's going to be actually a time delay that's one clue another thing is and this is really weird so if you look at the color of the light coming from the front and the back they're different colors any idea why
that's kind of a tricky one to explain actually I should explain the structure of the black hole so this is uh called the accretion disc have you ever heard of that accreting in astronomy just means like Gathering pulling stuff in toward you so an accretion disc is this thing that forms when the black hole is just like sucking in stuff from all around tends to form this disc around the black hole it's spinning the actual light that we're seeing is coming from somewhere else so before we talk about why the X-ray is coming from in front of and behind the black hole are different colors we have to talk about where the x-rays originally came from the source of the x-rays in this black hole are
essentially these flashes of x-rays that happen and the reason that they happen is kind of crazy it's this weird phenomenon that happens have you ever seen the solar flares when you get those like weird shaped curves so you get very similar things around a black hole when you get so much stuff and it's getting accelerated so fast around such a strong or such a big object like a black hole you get like electrons ripping off of the protons and atoms all this stuff just creates this spinning soup of crazy charged stuff and that produces really strong magnetic fields so super strong magnetic fields then you get these magnetic field lines that end up arcing and bending just like they do in
solar flares and eventually sometimes they'll snap and break and that process releases a bunch of x-rays so that's the source of your X-ray bursts almost like the light bulb and then the light's shining Down the Lights coming down to the back of the black hole and reflecting out and then it's coming down to the front of the black hole and reflecting out the light is you know interacting with like bumping into they call it reverberating like different parts of this black hole accretion disk and you're getting some light that comes out at a different color than the light in the back the reason why it changes the color of the light is like in light and like light collisions you change the color so if you've got like light coming
down onto one part of the disc that's moving in a different direction or different speed than behind then you're gonna get different we call it red shifting and blue shifting so that was the piece that I didn't fully understand when I first read these articles but I still think it's super interesting how light that came from outside the black hole came down here to behind it how could that get to us it can't go through the black hole because black holes don't allow any light to escape so any guesses well it's not light bending around it is yeah genius um a lot of the articles describing what's going on are like we've confirmed Einstein's theory of general relativity which is true because what the theory
says is that large objects actually warp space-time that's what gravity is and what that does is it allows light to bend around objects light is the thing that we use to draw a straight line you know like we use a laser beam to draw a straight line it's pretty groundbreaking that large objects can actually warp space-time okay so a lot of these articles are talking about how we're seeing for the first time like we're confirming Einstein's theory of general relativity we've already confirmed this before we've seen something called gravitational lensing many times and if you never heard of it lucky you because it's amazing this right here is a blue Galaxy behind this galaxy it's not a
circular shaped Galaxy instead of going off and you never see it's actually bending around the Galaxy and bending toward you so we've seen this before for decades we've seen gravitational lensing and that's the same phenomenon that confirms Einstein's theory of general relativity we're just seeing a really extreme version of it here the only way we're able to see light from behind a black hole is because of general relativity that's nuts Einstein you were right the coolest part to me is how creative these astronomers were in figuring out how to distinguish whether light was coming from in front of and behind this is the first time we've ever seen anything like this that's cool well
people are like what are you going to do with it was it an x-ray telescope like what are you gonna see what's gonna tell us that something was different you're seeing things like this an x-ray source that bounces off reverberate around the accretion Disco black hole and then tells you from a freaking point source 800 million light years away what the black hole looks like it's amazing all right that's your astronomy for the day I'm so happy so the reason I wanted to do this video is because my friend Ian from Smosh texted me an article about this he's like check this out because it's trending on Twitter and then jabril also tweeted out he's like I'm learning an explanation on this so if you guys have any random
things that are trending on Twitter or maybe if there are any scientists out there that maybe want to tell me before the news hits Twitter and I can teach Levi about it please send it my way yeah we thank you for watching thank you yeah and Happy physicsing
