Unraveling the Phenomenon of Gamma Ray Bursts and Supernovae | #381

Hi there, thanks for joining us. This is Space Nuts. My name is Andrew Uncley, your host, and it's great to have you along again for another episode, episode three hundred and eighty one. Coming up, we're going to reveal the name of Australia's moon rover. Yes, we're building one and we're sending it to the moon or nass there is in twenty twenty six. I believe it's the plan, but what do you call it? Well, I am going to prove beyond reasonable doubt that Australia has no imagination whatsoever. We'll also be looking at something that affected our ozone layer not so long ago, and this very strange galaxy that's been observed by the James Webb space Telescope. Well it was observed and then it wasn't, and then it was and then it wasn't. And we'll answer some audience questions about civilization types, tidle locking, and much much more, all coming up on this episode of Space Nuts fifteen Channel ten nine Ignition Space Nuts or three two one Space Nurse Can I reported Bill Good and joining us to chat about all of that is his good self, Professor of Fred Wat's an astronomer at large. Hello Brad, Hello Andrew. It's drawing to a close. Is twenty twenty three? Isn't sure as we speak? So yeah, we've bet to fit in as much as we can. We we should do that, and yes and more. I'm just I wanted to show you my my new toy. I bought myself an early Christmas present. I don't know if you can see this, can see that? Oh, look at that. That's the very elegant. That's the Boulevard Luna Watch, Luna Watch, and that's that's a replica of the one that went to the Moon with Apollo seventeen. I don't know if you can see the on the back, but it names date and the astronauts and the way it came about because they actually had commissioned a different watch company to give the astronauts watches, and the fellow who and that was I can't remember the brand off the top of my head now, but Amiga. Yeah, with the Speedmaster. But one of the astronauts broke his so he took his own watch, which was a Bullevar, and they were actually an improved watch for the moon, but they didn't get the first option and they ended up getting up there by accident, and so whila they became famous. So got myself one. Yeah, I knew you were going to show me a watch when you said you got yourself in an early Christmas present. I take it you didn't buy on a ship though, No, not this time. It was on I bought it through one of my son's my son's girlfriend's mother, who works for a watch company. But they had a at a Black Friday special, so I got it. I got it nearly half priced, so I was very happy. Yeah, yeah, but I'm loving it. Well, so you need to have to take half a mortgage to pea the full thie. Yeah, that's right. I really need to get over my watch fascination. But oh no, I think you're doing all right. I've got about six of them now. Gosh, I don't know what should you do. What we should do is get on with it because we've we've got to talk about this. This rover plan. Australia has been commissioned to send a or to construct a rover which will be sent to the Moon in twenty twenty six on a NASA mission, one of the Artemis missions. Now, apparently there were eight thousand submissions sent in to name this Rover, and twenty thousand people voted on the top four selections. Now the top four will cool them on Kakira Mateship, which I kind of like, and ruverav Er as in Kangaroo Ruver, and the winner is Ruver. I mean, come on, thirty five percent of the vote went for Ruver, so little imagination. So I am so disappointed, Fred, I really am am. I can't really comment because the Space Agency is very, very close to the astronomy branch where I work, And in fact, the director of the Space Agency actually asked me if I take part in the selection process. Oh, okay of the name this. Didn't know that a couple of months ago, so he asked me. I said, yeah, but delay to do that. He said, yeah, it's stronger at large. I'd be great for you to do it. Yeah, that'd be fantastic. And the next thing I heard, the chosen the name. So so it just disappeared into the ether and it never happened. I think, I think you dodged a bullet. I might have done. Yeah, yeah, I might have done. I mean, I'm surprised really because Kuliman was is Kulim on one of the indigenous names for the moon. I think that's the case. Yes, that's right, and made ship's obvious because that's an Australian thing. But and kakira is an Indigenous word as well. Yes, yes, that's right. And I would have Yeah, I would have. I was surprised with him yet one of those Yeah, I am too. And there were a few others that I liked, Matilda. I guess they were just sort of hanging on the on the soccer team's success this year. Blue Now, I thought that was a good name Bluey the cartoon character about the blue healer dog. But Blue is a dog's name. Rover is like a dog's name. I thought maybe that could work. Then they went with Skippy, like Skippy the bush kangaroo, warm bat walk about. Now. I thought that was good, except the thing doesn't walk. And my favorite Rover Mcrover face. I was going to say, at least it didn't get mc face. And there was another clever one, but people overseas won't get it. Rover McManus. Oh, yes, after the TV host Rove McManus. Although he did work in for America for a while so some people might know who I'm talking about. And Bert Newton because his nickname as a TV host in Australia was Moonface Moon. So that and then there's the obvious ones Steve Irwin, Sam Kerr, Red Dog named after a famous movie character that was a dog, Mad Max, and Blinky Bill, which is another cartoon character a kohalap. But yeah, it's going to be called Ruver. I'm sorry. I just honestly, that would have been the last thing I voted for, so all about personal taste, isn't it. It's one of these things. Come on astral It's better than you know, CEE ninety one forty two or something like that, which if it had been an astronomer, that would have been what it was called. Yeah, I actually like that better than Ruther as well. Sorry, I just think it's I think it's a shockup. But anyway, we're stuck with it. The public has voted, and this is a democracy. Probably shouldn't be after that, but anyway, maybe there'll be a coupdaeta before we launch this thing and they can change their name. Let's move a line. I think I'm overreacting for it. Well you are. You are turning out to be a bit prickly about this. Have to say, does it say? I can't really comment because I'm too close to the ocean. Not that I had anything to do with it, although it was a near thing that I didn't know anything. Like I said, I think you're lucky avoided it. But let's talk about this other thing, this super and over explosion, the gamma ray burst that heat Earth a couple of months ago now. But what it did was extraordinary, And what's even more extraordinary is where it came Fromrew. Yeah, So gamma ray bursts, as the name suggests, are bursts of gamma rays. They actually were discovered first in an interesting way, Andrew, because there were space Because gamma rays don't penetrate down through the atmosphere. They interact with the atmosphere, but they don't penetrate the atmosphere. And so back in the I think it was in the seventies, a flotilla of spacecraft were launched to detect gamma rays coming from illegal nuclear tests at nuclear atmospheric tests. It was all part of the Test Bound Treaty. The Atmospheric test Bound Treaty. Satellites were put up to monitor the Earth to make sure nobody less off a nuclear weapon clandestinely because you'd pick it up. And what they picked up instead was, yes, was the the celestial version of a nuclear explosion. They picked up gamma rays coming from from space, and bursts of gamma rays, which which last minutes rather than seconds, are like fast radio bursts, which are milliseconds. Gamma rays are a little bit longer, but they're but they're typically a few seconds long. This particular one is called GRB two two one zero zero nine A. That's a great name for a rover. Yeah, yeah, that's right. Yeah, sure you could, yeah, ground roving body gamma ray burst. Yeah, there you are. Yeah. So it's and it is. It's unusual in two ways. First of all, it was very bright in the gamma ray spectrum and also lasted a long time. I think it lasted seven minutes, yeah, seven minutes long, but was detectable. It's sort of you know, after glow, if you can call it. That was still detectable for something like ten hours. And that contrast with most gamma ray bursts because they are detected in gamma rays and then they fade away very rapidly. And so basically a number of spacecraft have been built that can respond to a gamma ray and this one was discovered actually by two gamma ray space observatories, one called the Neil Gerrel's Swift Observatory and the Faermi gamma ray space telescope both picked up this thing. And if so, if you can do that, pick up a gamma ray burst before it sort of starts sort of fading away, and that's usually a very short time. What you can then do is alert the ground based visible light telescopes to go and look at the place where where this thing was observed, and that is what is usually the case, but means these telescopes have got to get onto it very very quickly, whereas this one lasted for ten hours. And in fact, there's actually a very nice time lapse set of footage that was produced actually by the Fermi gamma race based telescope that shows the thing blasting off and then you could see that it's still there for the ten hours later. So it was you know, it was even observable in visible light by amateur astronomers work that one out. So this is a really really bright object. You know, you don't need the world's biggest telescope ground based telescopes to see it. So if you had a telescope pointed at the right place at the right time, you would have Yeah, you'd have seen it. That's right. So now it's the fact that it could be observed in visible light means you can pick up its distance, you measure its redshift, and it's two billion light years away. So this is not on our doorstep significantly in the depths of the universe, but it actually had made changes to the Earth's atmosphere which were detectable for quite some time. It's actually the sort of ionization properties of the atmosphere, and by that I mean atoms that have been stripped of one or more electrons. These are iron artist particles, and it includes the ozone molecules that we know so much about. They're the ones that absorb the ultra violet radiation from the Sun. That's you know, we've talked a lot about the hole in the ozone layer that came from the use of chlorofluoro carbons in refrigeration all of that stuff. Well, this gamma ray burst affected the ozone layer. It actually changed the levels. Yeah, fre it, it does a bit, doesn't it. If you've got something two billion light years away that can deplete ozone in the atmosphere, then it does. It just underlines how vulnerable our our you know, our planet and its its surroundings are. Apparently that's that effect. The depletion of the ozone lasted literally only minutes. It was not something that you know, lasted for hours and suddenly you radiated the surface of the Earth with ultra violet. It was a few minutes and the ozone layer fixed itself. That you know, the atoms electrons reunited. So it wasn't a serious event, but it does. It does suggest that if you've got super and over explosion and that that's kind of basically what gives rise to gamma ray bursts that's nearby, it's telling you that it can make a significant difference to our planet and its environment. So I would not have expected something that far away to have any impact on us whatsoever. Yeah, that's right, so would I. It is being touted as a once in ten thousand year event and is being called a boat boat the brightest of all time is the same one we were talking about. I think it might be, yes, because it was back it was last year as the ninth of October twenty twenty two. I think we mentioned it before, but what we haven't mentioned before is the fact that it was price enough to affect the atmosphere of our planet. And that's the big news story that concerns this, and it is really quite remarkable. Do we know its exact origin? Well, these things, as I said, still a bit mysterious. I think they're better understood than when they were first observed back in the seventies. That what what you've got is effectively probably a super and ova. Uh, it's this this still many different interpretations of gamma ray bursts. One one is, okay, you've got a super and ova that is a star whose mass is bigger than what would allow it just to collapse to a neutron star after the explosion. Uh. And this you know this, if you've got something that's more massive than that, then it'll collapse to a black hole. It's the common formation mechanism for stellar mass black holes. And we know that they release lots of energy, not just electromagnetic energy, but gravitational energy as well, which is one of the reasons why they were getting so excited about the the the Lego Gravitational Wave Observatory because it can detect these events as as can other other detectors throughout the world. Virgo is the other one, and in Italy and Kagra in Japan. If I remember rightly, I think I'm remembering the names correctly. I might not be there, but you know what I mean. It's it's it's the really high energy end of astrophysics. It's really extraordinary that the processes that go on. And there are still some questions about gamma ray burs we we I think it's true to say that we hadn't tied them down yet as to what exactly the the basic mechanism is. We think that there's that it's partly due to jets of material being emitted from this collapsing star. Uh. And you know that jets have to point in the right direction for you to see them. Yeah, that's of material. So there's all that on into the mix as well. And you know, just to add to the complexity, we've got fast radio burths, which seem to be something quite different. They are probably flares on magnetars which are highly magnetized neutron stars. But all these things that you know, Gosh, when I started my career, we had no idea about We didn't even know that there was gamma rays came from its face. Yeah, it's quite incredible. I suppose that sort of spawns several questions, what if there's a super nova closer to us, does that mean we're potentially more exposed? And beetlejuice once again comes to mind. Yeah, yeah, that's right. Beetle juice is not five hundred light years away something like that, which is a closer than two being it is. Yeah, that's right. So a gamma ray burs from beetle juice, yes, would be especially if it was a boat so arightest of all time, it would be a bit catastrophic for the atmosphere. Yeah, yeah, all right, Well, let's just how it's looking the other way when it happens exactly. Yeah. If you're talking about the material that's being directed out, you know, in relativistic jets, then you do want it to be pointing the other way. Okay, Well, you can read all about it online. It's everywhere. That story, it's made the New York Times, it's it's on several websites. It's it's definitely worth a read. But I imagine fred that someone somewhere or do a bit of a study and write a paper about this at some stage that it seems like it's it's that sort of topic. Yeah, they know that there are there are papers. In fact, I should be able to give you the title of one of them. Oh, there you are, let my hands on it. At the moment, it was, I can't remember where it's published. I think it's the Astrophysical Journal, and I can't let my hands on the reference to it. It's it's a European discovery. Just to give you a bit of a bit of a close ece. It is probably Astronomy Industrophysics, which is the European jourbil Okay, very good, Yes, And if there's anything more to learn about it going forward, we'll let you know. This is Space Nuts Andrew Dunkley here with Professor Fred Watson. Let's just take a quick break from the show to tell you about our sponsor, nord VPN. Now Virtual Private Network is a great way to protect yourself from all sorts of nefarious situations from hackers, to spammers to well just about anybody who wants to get hold of your private information, your bank details, your passwords, your name, sell it to the dark web, and your usernames and passwords are highly valuable commodities and there's a great way to stop anybody getting hold of them, and that is to use a virtual private network. And there is no better than nord VP. Now as a space nuts listener, you get a special deal as a Nord VPN customer. 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That's going to see maybe your bank account empty. You just don't know. These days, there's so many scams around. So check it out nord vpn dot comash space nuts and get the deal. I honestly think it's one of the best things I've ever done. Nord vpn dot com slash space nuts. Now back to the show, Space Nuts. Now Fred to our next story. And this is sort of a telescopic revelation, initially involving the Hubble, but now with the James web Space telescope up, they're doing all sorts of amazing things. They've been able to nail this one down a bit better. The popular press is calling this a ghost object because it sort of comes and goes, which is just a popular way of getting people to read your article by putting the word ghost in a headline. But yeah, what exactly are we talking about here? So we're talking about an object. So you know, it's been called the reappearing disappearing galaxy, which is what piqued my attention on the news media because they got you too, they did, because they don't galaxies don't do that. Hello, Hello, Hello, there's something Yeah, what's all this? Then? What's all is that? But what it means is we're talking about an object that is visible at some wavelengths and not at others. That the bottom line and so this much much less exciting when you say like that, it's all, yes, exciting is Ruver? You know, I'm going to keep dumping on that. You are going to Yeah, poor old Ruver. You know, you know, Andrew, you've got with a name like that, something's going to go horribly wrong. You've got to Yeah, what will go wrong is you'll decide in the end that you like it. You'll face up to it, You'll think, oh, yeah, it's not going to happen. Okay, Well I'll give you another name. Because this galaxy is not called Ruver. It's called as Tech seventy one. Oh I like that quite common. Yeah, so it's a TE double C seventy one. I should have checked what that is an acronym for. It's one of the survey is one of the many surveys that astronomers beloved off. They do surveys and then they call the objects a number followed but preceded by the survey name anyway, as TECH seventy one. So it was first found some years ago by telescope I used to have a bit to do with, although I never observed with it, the James Clark Maxwell Telescope in Hawaii on the summit of MANORCAA that is a microwave telescope which was operated for many years by the Royal Observatory in Edinburgh, which is where I used to work, and so my colleagues were very much microwave engineers. They built the world's first microwave imager, the world's first you know, image sensor for microwaves, which is called scuba, and that was a big deal in Edinburgh and used on the JCMT, the James Clark Maxwell telescope. Anyway, the object was detected first in those wavelengths which are sort of sit between what we might call the far infrared, the redder than red light that's very redder than the red, and the microwave reached sorry millimeter wave region, that microwave region, and so that was when as Tex seventy one was first found. But it was followed up by our old friend Alma, the Alma Telescope in Chile, which is kind of super deluxe version of the James Clark Maxwell telescope with an array of I think it's sixty odd dishes at a ridiculous height place called shan yantor not far from San Pedro to Atacama, where you're in the northern Ata Karma Desert, very very dry, and that's why Alma's so good at what he does. So it could be seen in the microwave spectrum that Alma looks at. Now, the thing is that with an object like this, what you want to do is see invisible light, and that's enter the Hubble telescope into the story. But it ain't there in the hubble and that's why it's appearing disappearing galaxy. It's not visible invisible lies. And that tells you that you're looking at an object that is a bit peculiar because it shows up in the microwaves and I guess what you might call the far infrared, the sort of stuff that Alma and jessemt can see but not invisible lights. And the reason why it's coming to the headlines now is that our new toy, the James Webspace Telescope, which is an infrared telescope, has detected it and indeed given us some very nice images of this object. It's only visible in the reddish that the reddest part of the infrared spectrum that the James Web telescope is looking at. So it but it is there, and it's the fact that we can now see it with an infrared telescope as well as the microwave telescopes, but not in the optical. What it does is that gives you a clue to what's going on here, and it turns out that what you're seeing is a galaxy which is basically enveloped in thick dust interstellar dust. Now we know about interstellar dust from our own galaxy. That's what causes the dark streaks in the Milky Way. It's what causes the coal sack that blob, the black blob devoid of light near the Southern Cross. It's in First Nations tradition, it is the head of the EMU in the sky, a typical dusty region of space where there's so much dust that you can't see the stars behind it. What's happening with as Tex seventy one is that the whole galaxy is in a kind of coal sack. There's dust around it. That means that you don't see the stars within it what you see is the dust itself radiating infrared, because dust actually does that, it gets heated up by the stars and radiates in the infrared. So that's the interpretation of what we're seeing here. A paper published in the Astrophysical Journal with a very very large number of authors that the paper draws the inference from that because this object is not visible in optical and optical wavelengths in visible lights, it's not seen in visible lights. It suggests that since most of our surveys of galaxies are done with visible lights, maybe we're missing a huge number of galaxies that are actually like this dusty galaxy, and there's so dusty that they don't show up in the optical surveys. And so it's kind of potentially opening up a new area of astronomy for scientists who have not really considered this possibility that there's a there's all population of dusty galaxies that we're missing, which is an important piece of work really, So University of Texas, Austin and other institutions a very large number of authors of this paper, which is entitled a Near infrared faint far infrared luminous dusty Galaxy at Z of order of five in Cosmos web. So if there was no dust in the way, we would see it invisible light. Yeah, exactly. Yeah, if it wasn't sort of encased in a cocoon of dust, then we'd see it. Okay, does that mean we are somewhat hidden from certain angles too, because there's a lot of dust at the center of the galaxy our galaxy, isn't it. Yeah, that's right, And so yes, if you were looking at our galaxy from the outside, you would always see it, because there's not that anything like as much dust as as tex empty one's got. But if you looked at it sort of edge on, so you're looking at the thick at the disk of the galaxy from the side, you would definitely see dark markings throughout that disc, very strongly dark markings, which will be the dusk in the sorry, the dust in the disc of the Milky Way, not the dusk in the disc of the Milky Way, as the other said, but the dust in the disc of the Milky Way. So we're a galaxy that's still still sort of forming styles. A lot of the material of our galaxy is actually hydrogen rather than being dust, which is the case in this other one. So this could this discovery could open the way for further investigations into other potential galaxies. Yeah, that we've now that we've learned this kind of situation exists. Yeah, So what you do is you get a telescope, well, well like the you know, the Alma or the JCMT or the James Web telescope, and you do a survey. You do as many, you know, as many as much of the sky as you can because these things are visible in those telescopes. The problem is, all of those instruments tend to be not what you call survey telescopes, for which you need a wide field of view. So with a survey telescope, you want to observe as much of the sky simultaneously as you can and then go on to the next bit, rather than having this you know, kind of drinking straw view of a little bit of sky, because then if you're try to do a survey with that, you've got a tiny distance between that field of view and the next one, and it takes you decades to cover the sky, if not hundreds of years depending up. Okay, that's fascinating, but yeah, if you'd like to worry about that you can find it well, you can find it on the as TIC. If you do a search for s TICK you'll find it as TICH seventy one with double s say as tech seventy one. This is Spice Nuts Andrew Dunkley, Hey with Professor Fred Watson, three Space Nuts Ready for some questions, Ran, why not? Why don't we do that? For We've got one question and a couple of text questions that have come in. We'll firstly be heading off to Germany. Hello there, This is actually from Germany and I'm a huge fan of the Space Nuts podcast. My question is a two part question. The Kardaship scale is used to define the types of civilizations into type one, type two, and so on. Humanity is considered to be zero point seven. It's believed that we would be able to achieve this type one status in the next one hundred years. So my first question is what do you think about the scale and is it actually used in astrophysics and cosmology to search for other types of civilizations? And as we know Tape two civilizations are the ones who can harness the total energy of a star. This is hypot says, but constructing a dacent sphere around the star. So my next question is that is it actually possible to construct a mega structure that can cover the Sun. Would like to know your thoughts. Love the podcast, keep up the good work, Thank you, Thank you, Ashkara hap I got your name right, But this is fascinating. We have talked about Dyson spheres before. We've talked about different types of civilizations and where we sit in that spectrum. What do you say we're at point seven with just a bit sure of being a type one civilization? Do you want to expand on that, Fred before we try and answer the question. Yeah, And I'm going to cheat because I did write a little bit about this kind of thing in my kid's books. I saw you reaching for that to grab it because it completely forgotten about it, and that partly answers the question. Astrophysicists don't really think about this sort of thing. A few astrobiologists they do, but the consensus of astrophysics generally and astrobiology is that we could be unique, certainly in our galaxy. So it's not really much point in talking about these civilizations. But let me just read a little paragraph. Because my space warp had lots of little breakout boxes, which we call techno. I'm just throwing something before you start to please, just in time for Christmas, right, thank you for space work. Yeah, yes it is. Yeah, it's interesting time because it's a great book full of cartoons, full of pictures of Yeah. Anyway, never mind, this is not an advert. What I said was because this is to remind me, because I can't remember all this stuff. It says. One measure of what an advanced civilization work can do is the amount of energy it can use. The idea was proposed by astronomer Nikolai Kardashev in nineteen sixty four, who devised a scale of civilization based on energy resources. For example, imagine a civilization that gathers all the energy from its parents star by building a sphere of solar panels around it. This so called megastructure is known as a Dyson sphere, named after the physicist Freeman Dyson, who popularized the idea in nineteen sixty. If Dyson spheres exist, they should be detectable by their infrared radiation. So far, no one has found anything like this. Now I'm not going to go into the different types because can't remember all that stuff. Type ones and type twos and things of that sort. But the question about, you know, are we as a civilization anywhere near the idea of building megastructures. I think the answer is no. Well, i'd agree because we can't even name rhaders. That's going to cut. There's got to be a clever name for a megastructure that's got kangaroos in it, please know. Yeah. Anyway, so Dyson spheares goe not go one. Mob mentality. Oh I love it. Yeah, I love that, Yes, love that. For those I know, a group of gank kangaroos is called a mob. Indeed, that's the collective noun. Yeah. So, I mean, you know, all these are really interesting concepts. The Kardashief civilization scheme. Check it out, you know, to our listeners, check it out. It's very easy to find that stuff online. But it's uh, there's nothing in astrophysics that leads us to believe that any of this is actually real, and and a lot of it comes from this idea, which I think is pretty prevalent among the people who really know about living organisms and evolution and all the rest of it. That the step from a single celled organism, which might be relatively common through the universe, from that to even an amieba. You know, a multi celled organism is huge. And one of the pieces of evidence for this, if I can kind of get on a bit of the hobby horse here, is that the first single celled organisms appeared on Earth within the first billion years of the Earth existence. So it's a very long time ago. And we see them, you know, their relics stromatolites over there in Western Australia. These are mats of microbes and they came into existence probably about four three point eight four billion years ago, but the first multi celled organisms we're only about seven hundred million years ago, So there was this long, long period three billion years where there was nothing but slime on Earth. You know why it took so long because Australians had to vote on what Australian microbes couldn't Yeah, that's right, well that could You could be right there because a lot of these microbes that we you know, the evidence for them we actually see in Australia waweather are some very you rest your case exactly. But yeah, so going back to it, you know, yes, it's really interesting to hypothesize on what advanced civilizations might do, and perhaps if we managed to survive, what we might do as a species down the track. But I think we are millennia away from anything remotely describable as a megastructure. We've got a very very long way to go. And yeah, you know, you never know once we start pulling helium three back from the moon. If that happens, we might not need any of these weird and wonderful things because you could build something the size of a toaster and use nuclear fusion of helium three quite harmlessly to produce electricity. That meands like exaggeration, but that's the bottom line is it's a it's a possible possibility for nuclear power, very clean nuclear power that might come down the track. MM. Fascinating. And actually I said, we're at point seven on that civilization rating scale. I can't know what that means. Actually, yeah, well it's it's a mute point at the moment, because after the Rover vote went back too point five. Yes, Okley, thanks actually lovely to hear from you. Let's go to a question from Ti Hi, Fred, and Andrew. The podcast is brill notwithstanding the names of rovers. He says here, Tim from Villages Hills, Sussex, UK. My question is why do planets and moons become tidally locked? Is it because one side of the planet or moon has more mass egen mountains? Will the Earth's ocean tides gradually slow down the Earth's rotation by friction and then it will become tidally locked to the Moon or the Sun. I'm lining up some black hole questions for the next time. Many thanks, and of course keep up the awesome work. Tim. I like this question. Yeah, it's a great question. As we talk about tidal locking all the time. The Moon's tidally locked to Earth, it's drifting away bit by bit. So he's sort of asked a what if question, But it's real life. It's not a speculator, it's not it's actually happening. It's happening. So probably the way to think to deal with this is to actually answer the second part of this question. First, is the Earth gradually slowing down in its rotation so it will eventually be tidal locked to the moon? Tidally locked to the Moon, And the answer is yes, And it's why one reason why we have to keep inserting leap seconds into the length of the day, which we've done since the nineteen seventies. I think, if I remember rightly, about twenty five times, either on the thirty first of December or the thirtieth of June. There's actually, at the moment, the Earth's rotation is speeding up slightly because there's other forces at play. There's a lot of sloshiness going on in the Earth's core and mantle, but the mechanism for that slow down. So just think of it in terms of the Earth. To start with. What you've got is our planet that's spinning once every twenty four hours. It's got the Moon relatively close by, which is going around it once every twenty seven and a half days. And the revolution of the Moon in its orbit is in the same direction as the spin of the Earth. In fact, most things in the Solar System are. They're anti clockwise, as seen from the north above the North Pole. So think about this. Here's the Moon in space, Here's the Earth. I'm drawing a diagram on my desk with my fingers. The Earth, here's the Moon. The Earth is spinning, and the Moon is it's gravity. It's pulling up a tidal bulge on the Earth. Now that but the Earth is kind of spinning underneath that, if you can imagine it, this tidal kind of directed towards the Moon. The Earth's still turning, and what it does is because of friction between the oceans and the Earth itself. And you actually don't need oceans for this to happen. It can happen in solid rockers. Well. But what's happening is that the bulge of the tides pulled by the Moon actually drifts slightly in the same direction that the Earth is rotating. And what that does is that adds a bit of gravitational acceleration to the Moon, which speeds up the Moon in its orbit. To respond, the Moon moves further away. So that's why the Moon is drifting away. And it's that friction between the you know, the tidal bulge of the Earth and the Earth itself spinning underneath. That is the friction that causes tidal locking, because it's gradually over time slowing down the Earth's rotation. And so the same thing would have happened the other way around with the moon. Very early in the moon's history, as the Moon was spinning, the Earth would have raised a bulge. Actually not in the moon it's not in the oceans of the Moon because it didn't have them, but in the rock itself, which acted as a break on the rotation of the Moon, and so it became tidally locked, probably quite quickly in the first certainly the first billion years, maybe even the first few hundred million years of the solar system. So that's how that process takes place. And yes, eventually in probably more than ten billion years, by which time the Earth might not exist anyway, because the star Sun will have turned into a red giant star. But over time, if nothing else happened, the Earth would be tidally locked to the Moon. If I remember rightly, the Moon and the Earth would rotate, would revolve around one another, always facing the same to each other. I think it's forty forty two days, forty five days, it's about that, rather than the twenty seven and a half days at the moment that is the month. So the month and the day become the same length of time because the Earth's rotation has slowed down, it's matched the Moon rotating around it, by which time, by the way, the Moon will be half a million kilometers as well the way, but it will be a stable situation so we'd never lose the moon altogether. It would wind up in this state. But as I was just saying, the super and ova effect will probably overtake it. Yeah, yeah, so is it? Sorry, Red Giant, Red Giant, Yeah, I knew what you meant. So we don't really we don't want a super and ova. We don't want to sup We won't get one with us. It's not massive enough. So the only good thing about a super and oval like that would be it would get rid of the ruver. Uh dear, But I wanted to ask you, is it a coincidence or is it a part of the effect of tidal locking that our rotation and the rotation of the Moon creates that situation we're always seeing the same part of the moon. Is that part of the same effect. It is just the fact that the Moon norse faced is the same way towards us. That was not a coincidence. It's actually a part of the Yes, it's exactly the effect, that's right. And so eventually, as I said that the Earth will be the same, the Earth will always present the same face to the Moon, just like the Moon presents the same face to Earth. So on what side of the Earth. You'll well to see the moon at all, you'll ever see it? Yeah, okay, so not nothing to do with mountains, Tim, It's all to do with that other stuff he was talking about. See how much I listen's still too. You're fretting about that ruver still, you know, pucket it out of my head for it can't still really bothering me. Thank you, Tim. Let's move on to our final question for this week from Daniel. Hey, guys, I am mediating a question from my father per discussion we had regarding time and space. We all talk about that at dinner. He's from Nottingham, England, so trying not to be biased. His question relates to relativity. How is it possible to measure the speed of anything if an object is relative to many points of reference. Eg. Two trains moving in different speeds to someone standing in the person on the ground, the speed is different, or more expansively said, trains are traveling at this at a speed across Earth. Earth is orbiting the Sun at one hundred thousand kilometers, And how the Solar system orbits the galaxy substantially faster, and the galaxy vastly faster than that, and so on? So how does one measure the speed of the train relative to anything? I guess the point is to calculate speed of objects. Does one always need a fixed point of reference? But what is that reference point when calculating velocity and distance of objects on an Earth or intergalactic scale. Is the reference point always Earth? If so? Why, thank you kindly, Daniel and Peter. I hope Dr Watson gets proofread it, gets to proof read this before the show. No he didn't. I just gave it to him. Then that's all right. But yes, it's a great question because you know, we're taught in relativity. Everything's relative to something else, So is there an absolute The question really is is there an absolute frame of reference? You know, is there something that you could say this is the stationary reference frame of the universe itself, And in a sense there isn't There isn't they have I put it that way so exactly as Daniel says, we tend to measure everything with respect to everything else. And it goes back to you know, when I was professionally measuring star velocities by the hundred, which we did with the uk shmid telescope. Here Siding Spring Observatory not far from you, Andrew. We always corrected for the Earth's motion around the Sun, so what we were doing was measuring those star velocities with respect to the Solar System itself. And that's fine. But we know from other considerations what the velocity of the Sun is going around the galactic center exactly as Daniel said. So if we're talking about looking at other galaxies, we correct for our motion around the galactic center, and you could, in theory, correct for the motion of our galaxy with respect to the Andromeda galaxy to get another frame of reference. So there isn't really an absolute frame of reference in the universe. There is one thing that did make people wonder if there was, and that is that when you look at the cosmic microwave background radiation, which is as you know, the flash of the Big Bang, when you look at that, you find that we've got a velocity with respect to it. I can't remember what it is. Actually it's some hundreds of kilometers per second, and that makes you wonder if what we're really seeing there is the motion of our whole galactic network with respect to the universe itself, and that might be slightly you know, it's just a slightly speculative interpretation, but it has been put forward as being an absolute frame of rest for the universe, the frame of rest of the flash of the Big Bang, because it's as fundamental as we can get. But the bottom line is that you know the speed of light three hundred thousand kilometers per second. That's been measured many, many times, and in fact it was kind of predicted as the speed of light before relativity came into being by James Clark Maxwell. These name's cropping up twice in there in this episode. Was James Clark Maxwell, a physicist, a Scottish physicist. He had a theory of electromagnetism which popped out this number. See. That's why it's called see because it comes from Clark Maxwell's theory. And it turns out that that was the speed of light. And it turns out that the prediction is three hundred thousand kilometres per second, and that matched actually all our measurements of the speed of light, which by the way, go back to the sixteen eighties with the Danish astronomer by the name of Wurma, who measured the speed of light by looking at the way Jupiter's moons behave, and he figured out that some of the things that were a bit peculiar about Jupiter's moons came came about because if the moons were on the far side of Jupiter, the light was traveling for a longer distance than if they were on the near side of Jupiter, and he could work out what that distant difference was, so he got a good estimate of the speed of light. Well well, well, well, well, well, yes, that's enough about that. But yeah, interesting, you know, relative, it is a good question and well framed. Indeed, I love that they're having those kinds of conversations. So and I'm glad they came to us to see if we could or you could come up. I am too. And look, I don't know Daniel, whether your dad wins the argument or your your your self wins the argument. But give my regards to Nottingham. It is where my niece lives. Oh lovely, lovely, thank you, Daniel, Thank you, Peter, lovely to get your question, and don't forget. If you have questions for us, you can send them to us fire our website, space nuts podcast dot com or space nuts dot I O. And while you're there, don't forget to check out the Space Nuts shop because you might be able to pick up a Christmas edition of Space War by someone who shall remain name us. But if you want a real book, there's other ones in there too. No, it's good, it's good stuff. It's a good it's aimed at children. That's the one that you wrote for kids, isn't it so that they can Yeah? Twelve twelve and upwards. People have said it's it's the best kid kid's book for adults on astronomy. I think that's the problem is is well, I'm gathering everyone who wrote it is also voted for ruver or read it. Read it. Sorry but anyway, but yes, I do log on our bit website to send us questions, visit the shop. We'll become a patron if you would like to do that and help us keep the lights on. Yes, mine's still on. Just got my electricity bill so I wasn't sure. That just about wraps it up. Thank you very much, Fred, great pleasure, Andrew. Good to have a nice, juicy episode to get our teeth into. We've got some great ground today. We sure did, all right. Thanks for We'll catch you next time. Sounds good. See you Fred, thank you very much. And to here in the studio who didn't appear today, well shame on you. The reason he didn't show up is because he voted for Ruvera And from me Andrew, thanks for your company. We'll catch you on the very next episode of Space Nuts. Bye bye. You'll be listening to the Space Nuts podcast available at Apple Podcasts, Google Podcasts, Spotify, iHeartRadio, or your favorite podcast player. You can also stream on demand at bites dot com. 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