THAT Black Hole picture ⚫ - Sixty Symbols

it is quite amazing I mean usually so this is a very big collaboration of people and usually word leaks out somewhere the sort of analogous thing that have not that long ago were the first results about gravitational waves and they're the were kind of nods and winks going on and if you knew the right people then you could probably get a little bit of an inside track this there has been absolutely nothing they've really kept it completely under wraps the data they're going to be presenting today was actually taken in 2017 so they've been analyzing for the last couple of years it's kind of the nature of this data it's incredibly complex or actually getting it to a point where you go from the raw data to something that looks like an impressive in image he's a lot of work and then so that would have taken most of the last couple of years but at this point they must know that they've got something good so this thing called the event horizon is kind of that point of no return it's the point where you can don't even light can no longer escape from from the region around a black hole the region we would hope to see today is a bit bigger than that it's probably about two or three times that event horizon size really because well it's because the distorting effects are so strong because what we're actually going to see is sort of light from a round of the black hole radio wave light and that radio wave light is originating a little bit further away and also this you've got this massive object in the case of the one in the middle of Milky Way it's about four million times the mass of the Sun which really means that the pause of light you think about light traveling in straight lines but because the gravitational field is so intense and the space-time is so curved the light actually travels in varied bent paths technique they're using as a thing called very long baseline interferometry so the object that they're trying to resolve the the size of the event horizon is about 30 times the radius of the Sun so it's absolutely tiny at the distance of the galactic center and the region that they're trying to see is a bit bigger than that but it's still absolutely tiny the analogy that's been drawn is it's like trying to take a picture of a golf ball on the moon okay so the technically and and the technique they're using really involves making the diameter of the telescope bigger and bigger and so one thing you can do is instead of having a single telescope you have multiple telescopes and then as you move them further and further apart the sharpness of the image increases because of the the ultimate sharpness is limited by the distance between your two most distant parts of your telescope in the technique they're using there actually recording the data on different radio telescopes all around the world Saudis enormous it's the diameter of the earth is the diameter of the telescope they're using but then the tricky part is then having collected all that data you then have to combine it all together and that's this the the technique that they're using this thing called very long baseline interferometry involves taking all that signal and actually it's soaked they collect so much data it's not something you can just transfer over the internet they actually end up recording the data on hard drives shipping the hard drives to a place where you can kind of correlate all that data together and combining the information from the telescopes to extract an image from it so the trouble is everyone has in their mind the movie interstellar right because they had the most amazing graphics of what one of these supermassive black holes would look like and they were actually you know they had real physicists involved in it there was actually lots of serious general relativistic calculations went into making those those graphics for the movie of course the trouble is they could do that at whatever resolution they wanted we're limited by the resolution that we can achieve with the wavelengths that we have with the diameter of the earth that we have which really means that you're not gonna see those incredibly pin-sharp images the whole thing is gonna be a bit blurry but hopefully it's going to be a blurry image of something really exciting and a blurry image of something really exciting is probably pretty exciting itself there is one other thing to mention which is that there's another candidate that there actually observed two objects so they observe the object in the middle of the of the Milky Way which is this black hole of about four million times the mass of the Sun they also were looking at the black hole in the middle of a much bigger galaxy Messier 87 in the middle of the Virgo cluster which is several thousand times further away so actually the the quality of the images will be several thousand times poorer because you're trying to look at something further away so everything's much smaller but the black hole in the middle of Messier 87 is several thousand times bigger than the black hole in the middle of the Milky Way and it turns out that two event horizon size scales with the mass of the black hole so if you've got a black hole which is a couple of thousand times bigger in mass then it's its event horizon will be a couple of thousand times bigger as well so the whole thing scales up in size so it turns out the ultimate sharpness of the image that they'll get from the black hole in the middle of Messier 87 is about the it's from the Milky Way and it's a bit of a toss-up which one's going to make the nicer pictures I think my betting still on the Milky Way because it's actually works that when you do the calculations it works out you end up with slightly sharper images for the Milky Way but there's not much in it [Music] [Music] these are not sufficient if you want to know what so for my chatting before their press conference I was wrong and I was right I was wrong because I picked the wrong black hole I said they looking at to the one at the middle of the Milky Way and the one in Messier 87 and I thought they'd be more like who did it find something about how one but it turns out that this is the one they got the result from today's announcement was pretty special actually because I've been working on black hold myself for twenty years I did my PhD in black holes and been working on it ever since in one form or another so today feels like quite profound day and to make it even more special I was watching the press release downstairs with my six-year-old son and he had this toy black hole with him and he was sitting there comparing it with a finger on the screen and it does look more or less as we were talking about before that there is is kind of ring a fire effect that or more particularly you're kind of not seeing any light from the middle there and it really is just down to this effect that the light is being so bent by this black hole somewhere in the middle there that the light you're seeing kind of coming out around the size is actually it being emitted around the back of the black hole and being bent right rounds have been bent by 90 degrees and more to head towards us into our line of sight and that really is sort of the definition of strong gravity right I'm coming late to the party here is currently 240 Nottingham time and it's been half an hour since the results were released in that time I've been interviewing prospective undergraduates and I actually made them sit down and watch the press release up until the point where we saw the image of the black hole and then I I thought we better get on with the business of the the interviews he said yes it looks it looks like our toy black hole but the real black hole doesn't have eyes and the real black hole isn't this cute cuddly as this one and he said my toy black hole doesn't have the ring of fire around it we know that light gets bent by gravity's has been known for actually almost exactly a hundred years the first measurements of this effect were made almost exactly a hundred years ago when they were looking at the what happens during a total eclipse of the Sun where stars in the year the Sun the position of the stars shifts a little bit just because the light from those stars is being bent tiny bit by the by the gravity of the Sun so we've known about this effect in kind of that weak gravity limit that things light can get bent a tiny bit by something as masses of the Sun now we're talking about light getting bent through ninety degrees and more and now you're talking about really really strong gravitational field so that gets us very much into that Einstein end of general relativity if you were just presented with a picture like that and say what's going on you could come up with many explanations as to what it was that there's a there was a cosmic doughnut out there in space or there's a sphere and you're seeing the edges of a sphere or whatever you know there are lots of ways you could explain there are many things in space that look like rings but the thing is here they said okay so we think that general relativity is right and we think there's a massive black hole in the middle of these galaxies and we think that it's got a lot of this sort of radio emitting material around it what would we expect to see if those things were the truth and then they predicted this is what you ought to see you pretty much and then you go out and take the picture and there it is and then so in some sense that's the best proof there ever is when you actually predict something before you go and see it and so I think this in that sense this probably used the best evidence there has ever been for a supermassive black hole in the middle of a galaxy again there are lots of ways that you can get those kind of a symmetries the most likely I think is that what's actually happening is that the material is rotating it's not it's not just sort of uniformly spread around there it's actually spinning around because we know further out there's a disk of material which is spinning around so the stuff we're staying close to the black hole it's probably in a rather turbulent messy way still rotating around and what happens is the bit that's coming towards you gets a big boost in energy there's this thing called the Doppler effect and in light the way one of the ways that manifests itself is that the light gets a lot brighter there's a lot more energy in it whereas the stuff is going away from you you see it a lower energy and so you basically see it as fainter and so I think that asymmetry we're seeing there is just to do with the rotation or material around the black hole I mean there was a lot of structure there as well that it looks like there's something that points out this way as well which I'm kind of intrigued by and again one of the things that might be expected is you might expect jets and material to be flying out of the black hole and the material would probably be rotating around those Jets of material so it sort of fits together but again that's kind of down near the the limits of what you can actually see on an image like that but this I really this is just my very first reaction to it so I am really looking forward to reading about the science that it's come out of this about whether the structures that I'm seeing in the background here are real and what they mean and just how these predictions match up not just on a qualitative level but on a quantitative level to the data that's actually been gathered I mean the other thing that you sort of have to take your hats off to the people involved in this experiment because you have to bear in mind the technique they're using VLBI it's not just like taking a picture with the camera you've got to take all these data from all these different radio telescopes combine them all together and from that so basically you take sort of every pair of radio telescopes and you get a bit of information from the sort of the phase delay the difference in the signal between each pair and each of those gives you a little bit of a picture but actually you don't have the whole picture and it is it's essentially because you know if you've got a regular camera you're kind of got your lens or your mirror if it's a telescope is sort of filling the entire aperture in this case you've just got a few dishes sort of scattered within your aperture that means there's a lot of missing information which means that you then have to kind of reconstruct that missing information and there actually there isn't generally a unique solution to this so there is a little bit of kind of prejudice that goes into this that says because you can you know there are many different images you could reconstruct from those data most of them look completely ridiculous and so you can sort of throw them out on the basis that they look unphysical but they're just very noisy or they just don't match what you'd expect from a real astronomical object and so there's sort of a lot of processing that has to go into turning this data into an image now what's going to happen over time is the more and more dishes get added to this network of telescopes so you have more and more pairs of telescopes which gives you more and more information so as time goes on they're going to be repeating these experiments with more and more information so the images will get better and better and there'll be less of that kind of interpolation of figuring out the missing data just because they'll be less missing data but for the moment there's a lot of work that has to go into turning the raw data into an image like this and so that's I think fundamentally the reason why it's taken all the time from when they took the data two years ago to now to actually produce an image like this from the data they collected so there's talk about putting radio telescopes into space because remember what dictates the sharpness of the image is how far apart you're most distant parts of your telescope are if you could put your telescopes into orbit if you could put one of them on the moon if you could put them all into orbit around the Sun then in principle you can make longer and longer baselines there's a lot a lot to this picture is there really it's likely you know it's a ring with a hole in the middle but actually I think that's absolutely astounding how amazing is that that the you know millions of light years away you can actually see a black hole in another galaxy down to the scale I mean the black hole remember the black region in the middle it's about three times the ultimate size of the black hole itself so the black hole itself is actually not much smaller than this we really are getting right down into that strong gravity regime right next to the event horizon of a black hole actually I'll say it exceeded my expectations with our simulations of what this might look like and they look more or less exactly like this but I thought all with scattering of light and instrumental effects and noise you know they'll be lucky to get it to get the prediction as accurately as that but it looks bang on so it's pretty pretty special so here we're seeing this radio synchrotron radiation from the immediate vicinity of a black hole you can see the black hole itself shadowing the light so you can see its influence it's pretty special yeah that people will be analyzing these data for years to come I think so it feels like I just feel like a real breakthrough yeah well I mean so remember you're looking at radio waves here so you can actually make these any color you want it to be fundamentally and they've clearly just picked something which look nice you know you could probably well have done it in black and white or you know because we're these are what you're really looking at here on millimeter waves not light at all so yes there are there is a certain matter of aesthetics as to what color you end up reproducing these images in and it makes a big difference that's the other interesting thing that you know NASA employees graphic designers who know what looks really nice because you do have that degree of freedom because it is all about how you present the data and you know it's not there's no dishonesty here in that the reason though right color cuz as I say these are radio waves radio waves I don't think the blue or green they're radio waves so actually you really can't pick whatever color looks nicest you know for galaxies the size of a football the supermassive black hole in the nucleus is the size of a hydrogen atom so that absolutely tiny but the energy they can produce is and they can more than enough to blow the galaxies the bits many times over so they understanding the link between these supermassive black holes like the one we found there else today and the broader galaxies that they're embedded in I think that's a really key issue for me personally it's an area work on how the galaxies form how do they switch off forming stars black holes may play a role and now we know that the really Oh black holes are there so of that we knew that before but we've got an actual image of one for the first time so there's been loads of evidence for black holes but no actual image to take a picture of one so it's P special we've made quite a few videos about black holes over the years I'm gonna put a link in the video description and here on screen also our astronomy channel deep sky videos we've got a video all about m87 already on there so if you want to find out more about m87 again links on the screen video description

Channel: Sixty Symbols

Views: 631,403

Rating: 4.9110222 out of 5

Keywords: black hole, m87, event horizon

Id: rflupY5Aa-Q

Length: 15min 10sec (910 seconds)

Published: Wed Apr 10 2019

Reddit Comments

[u/whatstheplandan33]

Dr. Merrifield is my favorite, great stuff Brady.