If light can’t escape from black holes, how can we observe them at all? Find out from astrophysicist Janna Levin, co-host Matt Kirshen, and Shep Doeleman, the MIT astrophysicist leading the Event Horizon Telescope project to study black hole Sgr A* at the center of our galaxy.NOTE: StarTalk All-Access subscribers can watch or listen to this entire episode commercial-free. Find out more at https://www.startalkradio.net/startalk-all-access/
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This is an unofficial transcript meant for reference. Accuracy is not guaranteed.
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Welcome to start off all stars, I'm Jana Levin and I'm your all star host today, I'm an astrophysicist, an author, but nowhere near is interesting as my co host the incredibly talented, I'm an astrophysicist, an author, but nowhere near as interesting as my co host the incredibly talented MAC caution. Matt welcome to the Ark a thank you for welcoming both on the show and for pointing out that I more interesting than lustre fas. Let's ride and we're gonna hold you to that for the rest of our interest. Also, in the studio we have special gas shepherd dull men who has a long list through general relativity ship is an astrophysicist at the Harvard Smithsonian Centre for Astrophysics and the director of the event HORIZON Telescope project event HORIZON telescope is a
I stick project not yet complete. Still under development. It is telescope, essentially the size of the entire earth that is going to try to take the first real picture of a black hole very exciting stuff. So this is what we have to talk about today. Reduce worker weaken, pulls off it's a good days work so, where work, where we're gonna be talking about black holes, how we observe them so far, why we think they're real and what it would mean. A real picture of them for the first time so shut thanks. So much for coming making the trip from MIT for Harvard breakthrough. Having moved to pleasure today, we're going to delve into one of the weirdest and short of most exciting topics in astrophysics. Everyone wants to talk about black hole and in particularly how we observe them. But first, let's just start with what is a black hole. Shap
every recently out for a strange. If I get it, I see how things are. Some was already putting favorites. I didn't go to school with you, you didn't, you know any is years go to ship to immediately ask about the by calls get you didn't do it from MIT world? Have you are always that look what they have a beaver on them? your ring. Is the MIT class ringing industrious and white appalling that I know her face. Is it because a building things are damning central telescopes vehemence black holes at all languages, so black holes blacklist? What are the writhing everyone as some idea of what a black hole?
but essentially it's when gravities run amok. It's when mass collapses in on itself to the point where gravitational runaway is inevitable and nothing can keep matter from in falling to singularity to appoint and the interesting in defining thing about a black hole. Is that what we all know probably know about it? There's dismembering call the event horizon around the black hole and ass. The point outside The singularity we're gravity is so strongly even light can escape northern hangs after the movie. The other way around actually about its envisages, what most people think about when they think about the event horizon the movie and the speech of the went into hell and then came back out haunted. So the event by some means. No events that happen on the other side of that line will ever be known to you, so it it separates causally ripe to parts of space at present even arise, and I can assure you that arose so. Is it an actual membrane? Isn't it
actual membrane, just a region of space time. That d marks were gravity is so strong that the escape. Lastly, from that mass is the speed of light once you pass through it. You really can't get back out again if you can actually stick a light pulse right at the event horizon and racing outwards. At the speed of light, it wouldn't go anywhere. We just sit there be frozen. It would be yet just hovering there. It's as though, almost space from falling, unlike a waterfall. So what would you see if you were actually right out of her ass? You would pass the light pulse and think it's travelling at the speed of light. So, but this is a good question that, because you say matter as a dense crushes under its own way, a big enough: star will crush under its own weight eventually, so is there stuff thoroughly people think of a black holes is incredibly dense, object but when I crossed the event horizon, like man asked, is there anything there are usually there? I think there has, for its awareness, is the wonderingly.
Of our galaxy or another galaxies. You just pass right through the event horizon like ass, not there, but you can get back out again. It's one of these strange things. That's why philosophers get region give me when you talk to them about black holes in a way that you don't when you talk to them about stars, because world lines can go through the event horizon and you don't know what happens either as well. I know what a world is where you the following space and time on your own trajectory- and I go from this point to that point from point a to point B. But if point B is inside the event horizon, you can get back out against. You can't tell your friends where you are or have you got there? You know how Google maps plots year, spatial path, they should use space, time diagram, and so the world lines your path through space and through time, but sometimes I get it wrong, picks like the wrong Massachusetts or whatever, and then it says you need to take a boat and then you need to take a left, turn right and then vote, and then you ll never escape. I gotta tell you that, but the thing about the GPS units is
do actually have to correct fur relativity to get your location rate on the map. So our clocks run a little bit lower here on earth than they do say at the satellites, and so they have to career for that time. Difference. The fact that our clocks, running slower, there were aging slightly more slowly in order to locate you properly on the earth? So that's usually interesting right, because I am going to do this theory of general relativity nineteen fifteen over two hundred and one years ago, an assignment I'm going back and talking Einstein saying here, Professor Einstein, you know a hundred years from now and have to put on the voice. I have the voice and the voices of sound good right, so you go back in time. You say to Einstein to taxi and everyone in the accents they haven't. You gonna started speaking british and don't give me die, but you you, you talk to Einstein. You would say a hundred years from now corrections that you discovered will enable me, with my phone to take down links from a constellation
later on the earth and pin point my location anywhere on the earth and, of course, he'd be very excited. You would say: what's a phone, because we ve our technology has gone so far beyond what Einstein had that before you ve been really is. The phone he wouldn't you refuse to. Memorize is phone number because he said why would I memorized anything I could look up clever your mind. Is browser answering you who are still here while he also say when I was a student, I was no Einstein so How do we know that these organs and life Sciences does that make us kind of on a path that right works in both directions? Also, I don't know why size phone number, so I have exactly the first idea. Reforms will actually clearly very similar. Wouldn't you ve had a phone number? Maybe so maybe this is one of those people, stories that I'm propagating without having properly looked at the Vienna. This is true of all so black holes, Einstein understood the mathematical solution
but he wasn't sure that they were real. In fact, he sort of thought nature would protect us from their formation. I mean, after all, I can't crush this desk very easily, it's very very hard to do. I mean it's hard to fold piece of paper more What's the number eleven times or something it starts to really fight, so he believed quite sensibly. Nature would not allow something to class all the way to a black hole and there were decades between that time. One thousand nine hundred- and sixteen is this guy in the trenches that infantry soldier on the russian front. You know it's calculating. Ballistic trajectory is in standby, the Einstein naturally, and he wrote down the first solution for black hold. You know where we're going. It got its name, the black hole, You gave it its names people's gave as well. We are also Princeton Guy yeah, it was sixty seven and eight
I am not tell you, I know I have written to the euro is a year. Shop was worn, and he was tired of seeing and state of complete gravitational apparently so someone from the audience shouted how about black hole and the name stuck that's fifty years right. Fifty years it took four people to really start to believe the black holes We are so. Why do we believe that we are now well, it was so well, but with where I think about it is that for a long time, people didn't think that anything could be much danger than water right. So, if you take our son that the average and see the sun is not too much more than water given its volume, but you fill the whole volume of the sun with water, we would weigh about with the Sun ways and it wasn't until people found white dwarves which are very dense in states system
like cinders of stars and it'll, be reinstated. Our son, for example, and neutron stars people began to really think that matter could be compressed to extreme density, just to be clear as the scientists who didn't think things to be done to them. So not just like people in the pub have varies. Like our my friend Jordan, telling me when we were eight that the way we could travel faster than light is refused. She saw the end of jaws, but like the way the canister like exploded in the shocks mouth so powerful and, like that's a big, an explosion, she can get and that'll get us like fasten the speed of light and it turns Wrong Jordan's. One of those people, apparently who write me, those you know their theories, everything the others I bet you do both sides is gonna. Look, I'm a search for the name, Jordan, my crazy for always give these letters. Einstein got it wrong by a minus sign of years. Why? Do you have a minus sign air in some of his first papers here,
but not in relatively me. He made mistakes. He wasn't really afraid of that and we need to stuff. Is you know it's not written on a tablet somewhere? It takes some trial and error. Sorry was more to Jordan theory. No, that was Firstly, I have had occasion to college organs theories. Basically, anything that can exploit a shock is gonna, be pretty powerful will. Actually it's quite amazing. They really needed to understand the nuclear physics that goes into the bomb technology before they were sophisticated enough in their understanding of small scale matter, forces to to realise that the black hole would form so so all these guys really did work on the bomb, but on that happy note where switching to cosmic queries, not what you got. Ok. So I'm a note. He is a question from a victor certain back on Facebook who says often stock or Sweden as well. Is it possible to kill,
Troy a black hole alive, a black hole hunt. It really like their words, putting a compressed air canister in the black holes mouth and they shoot here from a boat short, could easily like how our have to be to eat a black. How has it depends on what you mean by destroy it would like holes will evaporate by themselves. It is left to their own devices, but that's because of something called hawking radiation. The boundary the black. All this event horizon is a turbulent place and you can get particle pair production written one particle will go into the black hole and one will go out of the black or from a distance. It looks like the black holes, giving off particles slowly evaporating over billions of years, stellar mass black hole. And just vanish. I just one way to get rid of a black hole, just leave it alone, waiting for a very long time, ignored airline timing or right now. The light left over from the big bang is hotter than all the astrophysical black holes. We we think we know up so that the,
calls rain our absorbing the light right from the big bang they're, not admitting it yet a long time, though, everything will fall into black holes and then all those black holes will adapt. This is like a long like if this black hole is currently terrorizing. Seaside. Town like this is not the approach that you one yeah. That would not be a good yeah protective mother measure. Yeah that wouldn't work, but also a shark sized black hole would be short mast. Black hole, be really tiny. Can you make that? Can you have a black hole, those that size, oh sure, if you had a black hole. That was the mass of an asteroid. For example, that's a hundred trillion kilograms is a good sized asteroid. It would be smaller than an atom, so wouldn't terrorize the town. It would just drop right to the center of the Earth should be no support for well. You know we don't actually know how to force an asteroid to become a black hole, but there why direct pressure right jar, more bite in the large
John collider people were afraid that by smashing particles together, one of the by products was going to be subatomic sized black holes, and so people did, I think an injunction against turning on the large hadron collider. Now remember that being a thing did any many like micro, black holes, I should get created and if so, what happens? Awesome oh, like is worth utterly. Thank God reserves! Ok, you know someone were to happen. It would actually do bad things like you, even if it is delayed and actually so physicists, just never willing to say never through only willing to say it's very, very improbable, so the argument was black horse could be made. It depend on whether there were extra spatial dimensions and what gravity is really like higher energies. They were made. They actually evaporate through the process. Ships describing much faster than big, call. The smaller the buy call the faster the evaporate. So the idea is, they would just be gone in a flash. There would be like advertising? Member and broadly, I at least that's the theory.
Living your nose, so the thing that that people should feel safe about is that nature already done this experiment for us, so people worry about CERN and the large hadron collider, slamming particles together to make little black home, but cosmic rays hit the earth all the time in their hugely high energy, their higher energy. You can make in the elite, see so there's slamming into the earth all they haven't made a black hole, yet the devoured, the earth it made a black hole but and were black holes? Have these tiny little mouths right like huge animals will be attainable mouth riding? It was very difficult, leaving everything to shoulder? I really pretty humming bird exotic object world so doing. As more cosmic queries do so again, and I think this question might turn out to be slightly off in terms of waste phrase, but HANS one, five on Instagram! I don't know how you ask a question on this diagram. I dont know if this is just done by posing for picture conveys. This
what about a holding up a cardboard right? Oh maybe no answer from the United States says how close with a black hole have to be in order to see it with the unaided I the south high you'd have to see the shadow cask. That's all there is to see one of the mysteries of black holes are. We will get this later, but this is the perfect time. Is that by definition, you can't see them by in all. The action happens within the event horizon ones. Things fall through even light. You can't see it. So why are black holes actually some the brightest things we see in the sky? That's because all the gas and dust is being attracted to the black hole is trying to fit into this impossibly small volume, and, just as when you read your hands together, they get hot the friction of all that gas and dust madly. Trying to get to this team little volume heats everything up to hundreds of billions of degrees, see what you're, seeing as everything
clamouring to get into the black hole Robin the actual black hole assault. Yes, I it's like you know, like the line outside a nightclub rug. Something's happening inside therein is pretty special, but are you can see is like this be exciting line outside and the bouncers from like the heat, keeping people, everybody right where it, but then you think you know It may be its all hype, so it Shap wants to do is take an actual picture of the shadow, so that something amazing, but to see the shadow means there has to be something bright behind it. So if the black hole is just against a dark sky, there is no hope of seeing it in unaided, but if it was headed milky way galaxy shining behind it? You would see a sort of lens image of the milky way and that's how you would see the shadow so its initial question. How close would have to be its initial question, how close would have to be so a black hole size? The sun is about six column, so how close with six kilometres have to be shaped, you think to be able to see it
with the case of my eyes like right here. That would do within the solar system, based on your out. If Europe is, if you're out and at the orbit of PLUTO, for example, when you look back to the sun it you can see that right, o the EU have to be well within the orbit of mercury. I would imagine even see this kind of thing was Sebastian dubious on Facebook says: where is the closest black hole and could we send something to orbit around it? Well, that's great question: we often joke that, waiter study a black hole, descended undergraduate with a laser point or yours black hole and throw them in right as they go in the laser, of course, would be Doppler shifted and getting the right. They totally pass the course ok you're asking really getting there. Is there a black hole at the centre? The milky way is absolutely a black hole, this matter further away than the nearest black on earth, but twenty five thousand light years, where our case of the nearest black hole. Is that also part of the milky way ahead of this? Ok. So hundred billion stars in the milky way and about a million of them would say a hundred billion
But a billion of them actually will one day become black holes. Does it mean that they all are now so there's a lot of black holes, just speckled around the galaxy a lot, but we may talk about this later, but the black hole? The sort of Argo, too, is one of the only ones that we can hope to resolve with any kind of astronomical instrument through the kind of telescope. The agenda was referring to referring to before the event HORIZON telescope, can just make out the four million solar mass black hole in the centre of our galaxy? This is a perfect place to bank is going to come back to talk telescope and how it's going to resolve that shadow and the excitement of that projects are going to take a short break, but stick around so we can talk more, was shut and about event rising telescope Einstein HAWK Asgard. I have got no secret for you.
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Welcome back to start talk all stars as we continue to talk about black holes and event horizon telescope, I'm your hosting eleven and I'm very excited to have my wonderful committee composed Matt caution: Aegina hey mad on tablets, while in a few seconds and our science guest, Shap dollar man, ship is the leader of the event HORIZON telescope project. So tell me a little bit more about event: HORIZON telescope the event horizon telescope. Is a project dedicated to the notion that we can see something that we have always been taught is unsuitable? Rights are re knows there. Black hole is something that absorbs light matter. Nothing come out from the event horizon once it's gone into the event horizon, but because all the gas and us
is heat it up, and you get this effective three dimensional flashlight all around the black hole, illuminating it from all angles. You can see a shadow or the silhouette to the cast against all that hot gas What about interstellar Gina interstellar? They share the desk around the black hole, but you can kind of seed above and below. Do you think it was a pretty accurate Porto? I has very accurate, very rights, because it turns out that just like water going down the bathtub drain, everything could have followed this pancake shape fooling around the black holes make second disk black holes spin, the other way round in Australia,
It is not true, actually toilets. Do also speaking the australian I was just in Australia should protect only real experiments of our time. Your toilet astronomers spent a lot of time. Looking you, they will also spend all kinds of time that anything that, but the point agendas talking about here is because quite true, there is no behind of a black hole right so that they cannot wronged me. The anything is behind the black hole by definition, gets bent up and around so light raised from either side the black hole get back up and around. So you have this pancake object in your seat the rear side of it slipped up. Yeah. I stole his line from your ship. You you, you won't say you can't hide behind a black hole, actually a great description, crouching down behind the black hole and they can see you one step to closer in the black hole has about game. In that regard, I shouldn't have done that. I should hate attention in astrophysics clause rose, you reads on
Instagram is asking what is the telescope made of oh? What a great question so so, first of all, black holes are extremely smaller. The smallest objects theorize by signs gravitational theory to see them. You need a large telescope, the larger the telescope, the small the object you can see on the screen so to do this, we take radio dishes all around the globe and we synchronize them with atomic clocks. We point them all at the same time, it's kind of incredible when you think about a police swivel at the same moment, look at the black hole, take radio wave data from the outside of the event horizon of a black hole, and they were
on hard destroys. We essentially fries freeze the light everywhere around the globe and we bring them all back to a specialised supercomputer that compares the mall. It operates exactly the same way that an optical mirror does from optical telescope for an optical telescope. The light raise hit this perfect, perfect trapezoidal shape, and they focus at all to a point where your camera, since all the latest because to appoint and even rising telescope. We replay all of these recordings that we ve made all around the earth and we adjust the timing of them to make. It seem as though there is this huge dish, the size of the earth- and we synthesize this focal point, and that's where we make the image so the hearth is a telescope will telescopes around the earth for night say makes rightly makes this like giant machine. So how big I mean. I remember this comparison if you resolve the shadow of the well call from the supermassive black hole, the centre of our galaxy with,
is how how big it again it weighs about four million times were Sunday, and about how big, across as it were, on the sky it measures about ten micro our seconds and the shadow would have about fifty MIKE work seconds. This is the same as trying to observe your favorite citrus fruit always Angelo Route, Apollos ways? I honestly have a favours interest for it does than we are, and I am disappointed I get. Why have you not for in the past as it comes up, a lot of people are always like you know. What is, if you re like, doesn't like them all the same, and then why have you changed mad? You have to choose Stanley, one of those parents like you, can't love all of your children. The same. Why? I just don't have a favorite amongst when you Let's go to the moon. I want you to put one that you chose on the surface of the moon and we will try to resolve it with event horizon telescope for gags
on the show was someone it doesnt have furs. From now on, I heard it's it's like resolving a quarter on the moon is at the same. Almost is so citrus fruit on hinges. Route is bigger than a quarter, or if you were in New York now your friend was in LOS Angeles? Holding a quarter would be equivalent to reading the date on that quarter. Nasa you guys are. We are trying to do so. Much of being a professional scientist is coming up with different size. Analogies following that, a lot of a job like be like give PLUTO were a baseball and your words alpha sensory and your dad was throwing PLUTO from using light. As a lot of that, like it, we are, as I already ill. I fear that it doesn't really. They actually put this in terms of Poles and Wales
fruits. That's how I need, as I was hamsters, to have a trail of keeping this black all, which is four million times and ass. The sun probably fits in about three son wets, Does that sound like about right? I'm not. I don't know it's about player, but the little even rise. We both third, the orbit of mercury, so that data, because it four million times area, kilometer figure that you gave before, and I was quite large. Yes, it's quite like by its twenty five twenty six thousand light years away. Exactly so, as I said, black holes, they toss you stars round like planets. You know these supermassive once the hugely dynamically important, but though the largest one that we know that Most of us is twenty five thousand light years away. So it's not gonna hurt us without any danger. We are falling into it. Just really slow, very, very, like a much worse things. You're gonna happen to us in the next ten years,
Several did not get off topic. This is the biggest black hole in our galaxy is at the centre of our galaxy, and we think that there are black holes. This big in all the galaxies more or less, do we have any aspiration for observing the shadow of taking a picture of the shadow of another black holes, supermassive black hole in another galaxy, Zuzu friends out there is one other wonderful candidate. For windows so that the number one target for us is the supermassive black hole in this area. The milky way galaxy- I just I just called editor- is a star in the constellations had to terrorists. The other one is in the Virgo a galaxy and that weighs six billion times what our Sancho said today, you'll monster, it's a huge monster, a thousand times more than a thousand times bigger. The US about what were fifteen hundred times with the assessment, the milky way, different Galaxy hold Galaxy, and so that so,
The only reason why we have any hope of resolving that has caused so much better, even though much further away how much it away and fortune, or so it's about one thousand five hundred times more massive, whose also about one thousand five hundred times further way. So what looks about the same on the sky, so telescope with the same magnifying power would see them both of the same size? Do your basically building a telescope the size of the earth, to take the picture of two things? one tat they are like yeah. I like to see it this way if I were to be trapped on a desert island with two targets. These would be the two targets right. We have one that is a kind of a rose at his stone. If you well, it's it's an exemplar of most of the supernatural black holes in the universe. Their nondescript in smaller galaxies? We wouldn't see them if they were like him or where there are black hole is not bright. It's not me! It's not break because it's just not taken anything down right now, it was almost our diet.
It's gotta eating with you're a teaspoon, and so not it's not data that the gas round. It is hot, but it's not to really be seen from very very far away, whereas the further away the supermassive black hole is, is much much brighter and that's driving a jet of relativistic particles from its north and South Pole, its literally piercing the entire galaxy. Now is that because we are seeing it in the past when it was our active well well, is it not that far away worse where it is about? That's it about eighteen, seventeen mega parsecs over seventy million. That's the way it really old and I was not too old, replacing it as its eating as its driving these jets from its north and south pole through the galaxy. So in the past- was our black hole descent of our galaxy bright almost differently, so this problem some alien civilization on the other side of the universe, where the lights taking billions of years to get there that thinks that our black holes like a queen
are how'd you show. Is it couldn't be going better kidnapping showing that this is the best universe in which this show is going? The best works so eloquently trump, it's the best, its huge and it's the best. The who were also very briefly on this is that about three hundred light years from the centre of the galaxy. They see these wisps of x ray light, and they think that what causes that is three hundred years ago, there was a burst of activity in the centre of our galaxy and shockwave has reached the clouds that bound that area and its fluorescing suspicion, which were seeing the black hole twenties five thousand years it as it was, then so wasn't there. This excitement for a while that a cloud was about to be torn apart by the black call G to mass cloud too, and we watch
but watched it for how long where they watching this gas cloud, so that there was a gas, a cloud of gas that they thought was about three times the mass of earth. There was falling into the black or new they knew was falling in because the began to be tightly stretched to the front part of the cloud was feeling more gravity than the rear. Parlor clouded being sure is like streaming out right right, just like the exciting, but when you work in a more to drain under the bath like when it just suddenly, it's the only fund part of that that watch tower nobody in any event, people thought there was going to be fireworks, we're gonna be fired. And we haven't seen anything- has been the biggest dud arrive- that when we get so colors on Instagram saying, will this telescope be studying the effects of hawking radiation? Probably not so lucky Kyle, Carl
great question guy or sell textile from a man. Here, it's a great when we know that hawking radiation, but the event horizon telescope is going to see this outline and how can we region is not likely to affect that outlined? There's some cases in which it might there are some quantum effects it might affect the shadow size that an active area of debate right now, but hawking radiation itself is something that happens over a very long periods of time. I wouldn't say that dynamically affect the shadow. I should point out that we are getting cosmic queries from our audience through social media, so next time tune in and send your questions ahead of time and we may or may not actually get to them yet so play Jackson on Facebook asks. Could the big bang be the birth of a black hole and all we all living within a black, I almost think it would be the other way around. People have speculated that the black hole could harbour a big bang inside, so the black holes, much bigger.
The inside than it is It could be as big as the universe on the inside. It's like doktor, whose hardest you know you could in a small little red box, but inside Burma's lab, so you fall into the black hole and you think you ve got a microsecond before you had the singularity by your quantum bits, get blown out into a big bang. So the second part of question: why bless us all no living within a black hole. We could be like with his could be them. When we look back at the big bang, we might be looking back at the singularity inside a black hole. In that sense, it's not real. The inside. But in that sense, yeah, although most be, I don't really take that speculation very seriously its it, sir. It's intriguing contemplate. I always find myself kind of going back to that suggestion, no matter how many times you will tell me why its fall to hear what the problems are. There's something appealing about that was originally interesting about these singularity being in every direction. Rights with the big bang is everywhere. You look very soon
It is not unlike a black hole here, the singularity of the big Bang and the singularity of a black hole, or so similar, the people of just kind of tried to artificially so them together like a quilt and see if it matches. On that same note, day old chestnut rose on Facebook says, if sounds needs to pass through. Did the big bang actually make a noise in a sense, The big bang probably did make a bang in the sense that it ring the drama of space time. We're. You know. We imagined three dimensional space. Time is ringing in response to this kind of chaotic event, so in that sense it might have been made in a sense, a noise that, if we could record the shape of the ringing drum, we wait, interpret a sound ok. Even you think- of sound waves, not as being something we can here with our ear drum, but as being waves mediated by some kind of medium like gas. And also around the black hole via the accretion disk can support sound waves. Count it so this disc that you describe of all this material falling in around the black hole on flattening it out, it can have,
a sound with through that material? As long as you don't you think of sound waves, not as being something we can here with our ear drum, but is being waves mediated by some kind of medium by gas and the space time like a Brooklyn DJ does the council like is just not on it's your hands or something you can appreciate. The fear is that this kind of is also just about just the feel of the sky. It's time. You know, anyway, he's my disk important question also coming from Nix Spinelli on Facebook, and I don't know which of you too, is going to be the best to answer this. Can we send Hilary and from a black hole or they might annihilate each other? They got their way. You use your thinking about black holes, no matter how you feed them. They all look the same, you can take a black hole and you can fill it full hello, kitty, dolls. You can put old rusty refrigerators in it. You could throw Donald Trump into it. You could throw Hillary Clinton into it and
it's done settling down. You would have no idea what went into this is kind of deep. There is no way to tell the difference between a black hole made by crushing Donald Trump to appoint, and that me, by crushing Hillary Clinton, to appoint their master, a man that all partisans. At this stage we have, alas- Mccleery in our final few seconds, last minute at least let me see you take one from the international space station the last longer. This is their correlation between the law of conservation of energy and the fact that time stops at the speed of light. Does this have to do with light having no mass, because it is pure energy, says Jacob Seymour Facebook to agreed that again here, ok, so I'm gonna try this anything that has no mass will travel at the speed of light anything. So we think that there might be subatomic particles that, like nutrition some neutrinos, which might also have no mass and they would have to travel. Also at the speed of light,
and and their energy can be converted to empty squared equals, he's great energy but it is a pure energy of energy, one way to think of equals empty squared, which I struck upon. We would really like is to think of it as your kinetic energy through time The amount of energy transport by your motion through time, so we were to draw their space. Am diagrams. When you're running and your Google maps, you know you have some energy as you move through New York City by you haven't. Your energy using those through time and that's ecosystems, he's great energy On that note, unfortunately, we have seen a quick break, but we'll be right back with star talk, all stars. We can. There's some more of your cosmic queries was shut down and and MAC Version stick around release these inside
down to earth. Yours. This need to start welcome back to start up all stars were the topic of the day? Is black holes how they work? and how we hope to take a picture of our first black hole. I can think of to better people to talk to this topic then shipped omen and astrophysicist endless. The event HORIZON telescope project, and then very funny, Matt Caution who also hosts probably science, probably not science, publicized vessels, this is a problem and as citizens and probably not at that point, I don't live by the front. I'm John eleven you're all star host for today I want to pick up where Shap only that
as an telescope, because this is still a project under development. You're Talkin We will observe we hope to observe near these two object. So first, when do you expect to start making these first pictures of the black hole at the centre of our Galaxy Why are you going to do this good, good questions, so we started off on the event HORIZON telescope project by linking three radio telescopes around the world together in Hawaii in Arizona, California, and the first thing we realized was that the supermassive black homeless and of our Galaxy Sagittarius storm had a size that was predicted by this shadow feature so a hundred years ago. I thank him up with this idea that black or would cast a shadow, and we saw exactly that size that really got us excited.
Right because we only three telescopes. All we can do is tell the size of the black hole. Now we want to build instrumentation and put it all. The other telescopes that we can around the world is still in this earth sized telescope, and then we can make an image. That's the whole reason for doing this. It's a look at the size and shape of that shadow predicted again by Einstein to test whether Einstein's theories breakdown at the edge I call and also to stay the dynamics of matter around the black hole. Now we really be looking all the way at the event horizon, I mean, after all, light can orbit I call you know to act, We get all the way to the shadow. Are you really seeing given Heizer? You seem a little bit further out if we want to see a little bit further other something called the last photon orbit and light as fast as it goes. Also is constrained orbit around the block. All that saudi form, the space time knows it's crazy, crazy place. You could say under the flashlight,
and look at the back of your head, or you could eliminate the back of your head right in front of you you having about here. Do you would know what a medium ethically, because that's what you're worried about when you're in Is that a buckle? Yet? Would you Harold magically become bad just cause? It's gonna be sucked it. How much You would see how bad you think your hair feels gravity more strongly to the significant air light, certainly left behind what kind of be more free, the only to be more like high volume, what kind of sham through which needs either might be special black all products. I think we ve just started. Somebody right now is scratching out a memo. Their firm is suitable company, something else to be upset. A more and more ways to oppress women would haven't you limbs, which lightwood cellulite be changed. Black Hole, how we you're fired. Ok, I want you to endorse the Erika, your care products, but I'm not going to talk to that one, so you are making
first observations when brought so from these three telescopes museum. Beginnings. A global international consortium has formed and we are now instrumenting telescopes around the world so and Sheila, even the South Pole in France and Spain and so forth, in addition to the ones we already have and the new observations are going to kering in the spring of twenty seventeen that will be our first shot at taking the first image of a black hole, that's gonna, be a successful shot. Of course, I do be giving up every morning. Well a lot of times. Unilever experiments take decades in the first shot, not expected to be successful in new thing. In ten years down. The line will refined enough to really nail it, but you think, as early as sprang you're going to have an actual picture, we are eternal optimists and even even experiments that our long shots are always assumed, perhaps give a good result, if not by the way, to future intervene
does that make inevitable success in our reality, so we are really focused on success in spring or twenty. Seventeen on the same time, nature is nature. We have no idea we're going to see enter doesn't always comply. It does not always comply and we may fall flat interface, but the idea that we get up and we So is this a done deal the consortium, the International Calabria is his on board, and this is definitely going to happen absolutely so we have time on some of the biggest apertures from the biggest telescopes around the world, and we have these systems are going to freeze the light at all of these telescopes an unprecedented rates, I'm waitin for you sat waiting for you is there ever receive when you are setting up these huge telescopes you'll see something you didn't plan to see
like mad waving like a neighbor ability to date in this, but like I guess, I'm gonna have to report- is now a quarter on the moon is like a freckle on the neighbors yeah yeah, we're sir. So the Erika. Well, so let me just say that we think we know we're going to see, but nobody would be happier than most people in the consortium if we saw something unexpected. That would be hugely interesting and I would like to put it is that we will will perhaps be able to test Einstein's theory, but it's never wise to bid against Einstein, but if we see something crazy, if the size of the shadow is not what Einstein would have predicted, given the mass that black hole, we will be really scratching. Our heads thinking about alternate
Forms of gravity were thinking about objects, even more exotic than a black holes. With that mean that the whole theory of general activities is wrong and needs to be supplanted well, we know Jana that GR cannot be complete right because at the centre of the black hole, where everything is crushed to appoint the singularity GR has to come into bored with quantum mechanics and nobody- not even Einstein, ever found a way to do that. So we Oh jars, complete. This question is how how close to we have to get to the singularity before becomes evident could be at the event horizon. There could be manifestations of this deep mystery at the event horizon the thief and rising
oh scope: could your image so there you know new mentioned quantum phenomenon, hawking radiation, which happens at the event horizon, so quantum fluctuation of an empty space get stolen by the black hole on the other particle radiates and to an observer far away. It looks like the black holes actually emitting radiation. Is that something you think you could probe with this telescope week? We can see the hawking radiation itself, because that's gonna be higher energy particles. We know that something strange is happening if even rise right. There's this thing called the information paradox right, so would you throw encyclopedia into the black hole? What happened to the information in that is equal, Peter? I notice when its plans,
by Wikipedia that everyone now uses, and you free up a bookshelf candidates for photos. Unlike anything, it's real time savour leave these black holes, but if so, it turns out that that information has to go somewhere either the hawking radiation as to encoded as revamp rate or gets frozen onto the surface lots of different theories and in some of those whom the Quantum states inside the black hole may be in communication with the exterior of In that case, you could wind up with different orbits photons around the black hole in the shadow. Would look different exactly how different it might look, but there are ways to think about it from that framework. Now it's also possible that we just couldn't see any effect, but there is still something going on it's just too difficult to imprint it in such a macroscopic object
make it sound easy! It's! It's usually called what what we're doing I'm making it easy sat. That's down! I'm proud of you. Ok people like home one to build their own one of your telescopes rehash they go. They should not because we want to do. Competition and don't do that humbugs, it's quite difficult and by I would say that the only way that we are able to think about doing it is because we have a global team of exceptionally talented collaborators make it happen, so sometimes you have to kind of supple, make your own either right to be part of this bigger team. It's not alone pioneer, it's really a global effort, millions and its real privilege to work with all these people. I think it's
and for the cosmic areas lightning round. I think I'm supposed to deem this bow wage, I'm never going to taking instructions. I think that's what I'm twisted. What do we got? Mad arrive from shown Rasmussen whose a patriot patron- and I think you should have touched on this- already high docked eleven. Why is it the general relativity, the theory of the large and quantum mechanics? The theory of the small cannot be reconciled as one theory of everything, if I'm not mistaken, don't citizen discard general relativity as being a mathematical short cuts on a larger scale, but could these to be unified for the new discovery of gravitational waves or say aggravates on thanks for the show. Thus, when like cats and like loved complex, like grading alternatives, hope you got the accent right well, this is it. This is a really important question. I mean this is what all theoretical physicists pine for is a resolution.
The theory of gravity with the fear of quantum mechanics, so the large theory of the universe on a large scale, the theory of the universe on a small scale there very hard to put together. Even if I went through a kind of a standard programme. This is what I always do when I try to quantities, a model of the universe. It doesnt really work with gravity, because gravity is so non linear right. This is not in the the effects feed back onto themselves in these very calm plex mathematical ways that we don't know how to control. So literally, just don't know how to write it down. It doesn't mean it doesn't exist in reality? But we just don't know how to mathematically write it down or our tools fail us, and so many people of Chad justifying better tools. But it might be the case that there, actually not reconcilable a nature that gravity in some sense isn't a fundamental a force. So you know when I say the temperature in this room.
You know it's warm in this room. Temperature isn't an actual quantity that belongs to anything, it's the collect, the behaviour of group, motions of small things gravity might be, that it might be the collective behaviour of quantum entanglement in and phenomena like that and that when we, Look small enough. We realise gravity is not really a thing at all. It's something in a loose. In that only emerges on large scale. I mean the steps really interesting. We love not knowing answers right. That's why we have jobs. That's where we have something to we build telescope travesty, about on Facebook, says how the black holes affecting time Presumably there a shop, gravitational gradients in and around the black hole. If so, how do these affect the resulting temporal distribution of matter? Thank you for an interesting. So will you mentioned interstellar before initial, so they had this moment when people went clue.
The black hole and every hour they spent down. There was twenty years outside. That's a real thing right, so time really does slow down close to the black hole And they spend time down there and they came back and everybody was twenty years older, so that there is a door time, gradients near black hole and they do affected dynamics and when we think about matter and light orbiting, the black hole have to take this into account, I'm getting on which I was supposed to go more rapidly. Learning we're learning Somalia on Facebook says have these questions are of little elementary, but how much of our understanding of black holes relies on our standing? Quantum physics? Are there new values that employers the structure, black holes that we have identified. I mean in some sense astrophysics. Not at all black holes are typically classical kind of objects. When you look at them from the outside, we saw hawking, can radiation, we wouldn't really be able to see those quantum fluctuations, but there's a whole community. Petitions that are at their desks lieutenant paper who are studying only the quantum aspects only would find them in
different buildings on a university campus right, variances, Azure, Earl S, gray name on Facebook says how useful with space based radio, telescopes, beef or taking black hole pictures they be fantastic. So it turns out that one of the big problems we have is the earth's atmosphere. It's the water vapor in the atmosphere that similar to what makes stores twinkle for optimal telescopes that limits the event horizon telescopes over you. Take a telescope in orbit. There may have a telescope as big as the orbital size of that how bad isn't radio telescope having across while the largest, there, a single when we use about fifty meters across a hundred fifty feet across and then we have One in Chile that behind to get up in space, are right. My night is on Facebook says if two black holes one being a bit stronger than the other, what's a meat, would they in theory cancel each other out? They would just get bigger than just happened like I made that first detection and its net,
Therefore, an amazing resolved first time in history we seen two black holes collide, what happens as they make a bigger black hole, and some of the mass, though, is released gravitational waves, energy, and this is important- it, doesn't matter if the black holes made of matter anti matter, they dont cancel each other out. Thank you for the great questions. The lighting round, but sadly, where, at the end of our time today, it's been a great day here at star talk all stars once again thanks to Shap. If you want to hear more about event, horizon telescope go to event, HORIZON telescope dot, org and Matt on Twitter at that person who is co host of probably science podcast, which is especially funny when I'm on it and I'm Jan eleven thanks for listening, see around us. The devil may adopt the organs. Which you listen. The star talk, commercial, free, joint star, talk
I'm patriarch for as little as five dollars per month and the ads will disappear, learn more at patriarch dot, coms. Last star talk, radio,
Transcript generated on 2020-01-24.