#414: Stellar Collisions & Invisible Invitations: Unveiling the Universe's Secrets

Hi there, thanks for joining us on this a Q and A episode of Space Nuts. Andrew Dunkley here, good to have your company. On this episode, questions from James, Lloyd, Rennie, and Ron. James is asking about planet nine. Lloyd is asking about certain colliding objects in space. We talk about black holes knocking each other off, and neutron stars and black holes, but what about stars and stars or stars and stripes running into each other. I don't know. We'll find out electromagnetism and how visible are we to other civilizations. That's a really good question. We'll answer all of those and furnish you with a couple of comments from the audience as well. On this episode of Space Nuts. Fifteen said in Channel ten nine ignition quench Space Nuts NY four three two Space Nurse as An actually bought it. Bill's good. Let's get all the answers from his good self, Professor Fred. What's an astronomer at LA? Hello? Fred? Hello, Andrew. Can't guarantee to have all the answers, but well that's good. Now we're going to start with a couple of comments. These came in in the last week or so. The first one is directed at you, Hi, Andrew and Fred. Thanks for the shout out. Fred. We're Kate and Jeremy, the couple from the Central Coast who met you on the Canadian train. We ended up in Gander on the island of Newfoundland in Canada for the eclipse. We had clouds coming and going through the initial stages, and then right before totality, clouds came over and we never saw the sun again. Oh no, I still saw the surrounding effects. But now to see if we can get to Spain in twenty twenty six. Great to meet you and love listening to the podcast Kate and Jeremy and they can come to Dubo in twenty twenty eight and catch it here. We should have should have clease, guys, but you never know, do you. But you had the opposite. You had clouds and then they disappeared right at the last second for so that's right. And look, it was lovely to meet Kate and Jeremy. We were all in a very party mood at the time and I think they just joined it very briefly. But it was lovely to see them and just a quick plug. That was our Canadian tour that Kate and Jeremy's accepted on the Canadian train and we are going to do another one for the Spanish Eclipse twenty twenty six, so there'll be a tour there, so keep it touched, Kate and Jeremy. You never know. Yeah, fantastic with us. I think we're going to Gibraltar actually, which too. That place rocks. Okay, that was horrible and it was very quick though, Yeah, it was very quick. I should work in radio. Now I've got a comment directed to me. Just what to agree with Andrew. I'm trying to read The Three Body Problem. It's a book that's now been made into a TV series which I was intrigued by so much I had to get the book. Now. The book was written by a Chinese author and it had to be converted into English, and in doing so it sort of became a bit convoluted. I suppose it was a bit It's a bit of a tough read. And Ralph's messaged me to say, I agree with Andrew. I'm trying to read Three Body Problem, but I'm about to give up on it. No fun, Ralph. I have a solution for you. I've reached a chapter which is very highly technical and it's sort of explanatory notes about what they're trying to do at the research center that is the subject of the story. I have taught my iPad to read to me. Apparently you can change some settings in an iPad where it will read the book or read what's on the screen to you. So I'm getting through those chapters by having it read it to me, so I don't have to try and tangle with it myself. It works pretty well, So maybe you want to look into that. If you've got an iPad. I'm sure you can do it with Android devices as well. Don't well, I think you can do it with a kindle. They all come with spoken voice capability, I think. But that's how I got around it, Ralph, don't give up. The story is actually really good. The only problem I find is because all the characters have Chinese names, I keep forgetting who's who, which is a bit of a sad indictment on me culturally speaking. But I keep having the thing, now, who's that which one? Because when you separate names like Fred Watson and Andrew Dunkley and all, that's easy for us from a Western hemisphere, but the Eastern names I tend to I lose track of who's doing what anyway, that's just that's my suggestion to you, Ralph, get the book to read it to you rather than you struggling through it. Of course, if you've got a paper copy, nothing I can do for you, bless somebody else to read it to you. Maybe maybe now, Fred, they're all text questions today because I had a computer meltdown, not just in recording these episodes today, but last weekend when I was getting prepared, and so I lost all my audio questions, which I'm going to regather. So we're going text all away today. Planet nine. Should such a thing be discovered, does it have a name that's just waiting for the body to be discovered, or would the individual who makes the discovery be allowed to name their discovery following whatever naming guidelines exist. Thanks for putting a smile on my face. Fellow's name and then that comes from James. Now a couple of things. It's about planet nine. You actually spoke to someone on your recent tour who has a thought about the planet. But well we might get to that in a minute. The name, let's say they find it. Yeah, there's the Astronomical International Astrotomical Union is charged with the responsibility of naming it. But does did the does discoverer get us say in it? I'm sure they would. So the convention with planets is they're named after principally Roman gods, because that's how it all started, you know, with Mars, Mars, Mercury, Venus, and that was continued when planets started being discovered, of which the first one was yeah, the one that's upside down Neptune. Yeah, that's the other one. Sorry. Yeah, So until seventeen eighty one, when William Herschel discovered the object that became known as Uranus, no planet had ever been discovered because they were just known before that. That's where you yeah, okay, that's what through me. I was thinking, well, surely it was one of the inner planets that was found first, but no, they've just always been in our awareness and yes, that's right from you know truly edentry times, as soon as people started looking at the sky and you know, first nations people here in Australia would have known about them as well, but they gradually got associated with Roman names Mars, the god of war and this other thing, and so that would continue with the discovery of another planet. If it was classified as a planet. Now we have a glitch in that, because Pluto was classified as a planet when it was discovered in nineteen thirty. It was named, as you and I have spoken about before, by an eleven year old, a girl in Oxford in England, whose name was Venicia Bernie. She basically suggested the name Pluto to her grandfather, who was a mate of Herbert Hall Turner, who was the professor of astronomy in Oxford, and he telegraphed it to the discoverers of the Loyal Observatory in Arizona, and Pluto was agreed. But it was perfect because it was the Roman god of the underworld, and so that's a great name. Venicia was interested not just in astronomy, but also in mythology, Greek and Roman mythology, so it would have to follow that guideline. Unlike the objects that are discovered, like and these are important in this story because these are the one that suggest that planet nine might be there. The transit Neptunian objects objects in the outer regions of the Solar System, which now include Pluto. They are traditionally named now and again it's a convention imposed by the International astronomical union. But again it probably has, you know, the guidance of the people who made the discovery. They're named after deities in the First Nations culture of wherever they were discovered, So that, for example, is why and it's not a Kuiper Belt object, it's an interstellar object. But it's why Umua has a Hawaiian name because it was discovered on the island of Maui with the pan star's two telescope and Hawaiian word meaning first messenger from Afar. And so you know, when you look at the list of names of particularly the trans Neptunian objects, I'm thinking of Senna and thinking of Mahe mahe. I'm sorry, it's Maki Maki. These are names that come from the culture of whatever tradition it was in which they were discovered. But planets are given Greek or Greek or Roman names of underworld. Oh sorry, got of deities basically their deities. Yeah, well, I you know, something sparked in my brain when you started talking about the discovery and naming of Uranus, and I was right because I just looked it up. Herschel didn't name it Uranus. He named it Georgie of Sidis, which is named after King George the Third. Now we to call it George. Yeah, that's right, but they weren't. You weren't allowed to keep that it was. Actually, it's really interesting. There were there were three names. So he discovered it on the thirteenth of March seventeen eighty one Urinus Day, internationally Urinas Day, and so over the next twenty years there were basically different names given to this object. He was, as you said, he wanted to call it Georgimsidus, which means the Georgian star, named after the King George the Third, who already was showing signs of being a bit loopy, and that's why that was not a popular name. On the certainly incontinental Europe. There was a body of opinion that wanted to call it Herschel, after the discoverer, and that would be the case if it was a comet. By modern convention, we'd call a comet after the discoverer. But people didn't like that either, And it was actually Johannes Border, who was a very well known astronomer in Germany, who suggested the name Uranus is the I think the parent of Saturn in mythology, so it kind of you know, it works quite well. Of course he would have called it Urganness because he was of it. Than that's yeah, quite an innocent name compared with what we call it. Indeed, so the answer to the question is that the discoverer may have a say in it, but the International Astronomical Union will basically rub a stamp it and it will probably take the name of some kind of Roman Goddish person deity, King Queens. That's my explanation. All right, thank you for the question, James Hope, that helped. This is space Nuts Andrew Dunkley here with Professor Fred Watson. Okay, we take a space nuts. Next question, very interesting the episode about the neutron star collisions. You've spoken many times about black hole collisions and neutron star collisions. But do just normal everyday stars like our sun ever collide and what do they create? Thanks to the show Lloyd from Cans that's in North Queensland on the east coast of Australia for those who've never heard of Cans and it's not spelt c Ans now see A I. R. S. Kenes. Now, well the answer would be yes, I mean just about anything and everything could collide with something of its own making or something else, couldn't it. Yes, that's absolutely right, And you know the collisions are. It's not usually something smashing directly into something else. It's usually usually a dance. It's a dunce, that's right. Yes, very spectacular one where things basically circulate around one another. So if you yes, So if you brought two stars together, say about you know, one to two solar masses each, and then merge, then you're going to create something of order four solar masses, supposing there were two solar masses each, which is more than the limit imposed by the gravitational physics. I'm just trying to run this through in my head because it's something thought before, which is terrible, isn't it. So you might get super over explosion. Two big ones merged, they couldn't hold. That's right. You've got something that's that's unstable, so you might get a super and over explosion. I mean we see many instances. In fact, probably half the stars in our galaxy are in pairs which are orbiting around one another. We call them binary systems, and some of them are very close. Some of them are close closely enough to stort the you know, to distort the physical body of the star. There's something if you get it's something called the rocial limit. If you get within the rocial limit, then you're going to distort the body of the star and you probably pull one of these objects to pieces. So there will be tidal forces. That's the trick that tidal forces which actually tend to destroy the envelope of these stars. Anyway, really interesting thinking. I mean, we do know that planets can be goggled up by their stars, because we can see the evidence for that. We see planet type chemicals in the atmosphere of some stars. And so it's not that big a leap of the imagination that if you've got a binary system where they're very close and ones inside the rocial limit of the other, then you'll get a combination of the two and it might be something relatively gentle, or it could be super over I mean if it was gentle. By that, I mean what would happen something like a plan industry and nebula, which is what will happen to us some it will shed its half to layers and make a beautiful shape nebula. For anybody else who has to be looking at it from the outside. So yeah, a really interesting speculation. I think the answer is yes, two small stars could combine to make one slightly larger star. Is that realistic? Yep? Ye, two large stars just they just go Yeah, all right, very good. Thanks for the question. Lloyd was Lloyd? I should really format my list of questions better because I keep losing the names. But Lloyd and Hope all those wells from kings Yeah up in Queensland. Probably a Cowboys follower. This is Space Nuts Andrew Dunkley with Professor Fred Watson spacebuts okay. The next question, Fred, is about electromagnetism. Can you explain it as far as how it forms, how it behaves, how common it is on other planets? Do galaxies as a whole have electromagnetism and what happens to a planet that doesn't have it? Love the show. That's from Rennie Traub, who used to send in audio questions but has taken to the mighty pen or keyboard these days. Thanks for the question. Really nice to hear from you. Yeah, we talked about electromagneism magnetism. I think it was last week, wasn't It was very recent? Yeah, we it's the stock in trade of astrophysics, so we talk about it a lot. So yeah, so you know, we we can think about electromagnism in two ways. We can think of it as waves traveling through space, which is what gives us the phenomenon of electromagnetic radiation like radio waves, gamma rays, X rays, infrared all of them are infrared radio. Sorry, all of them are electromagnetic radiation, which are a different wavelengths or different frequencies, which is the same thing but turned upside down frequency being how how quickly they wobble wavelengthies O along the waves are so. But the other way to think of it as is and to some extent that you know, Ready's question is easier to answer this in this scenario. We can also think of it as photons because photons are the particles that carry electromagnetic radiation. They're subatomic particles. We know they exist. We were talking last week about whether the human eye is sensitive enough to detect single photons. We have the conclusion that we've seen research recently that said, yes, it is possible for the human eye to detect single photons. But yeah, so they're subatomic particles and they interact with other subatomic particles, the particles of matter. And so that's a great way of understanding how electromagnetic radiation is formed, because if you have you know to put it in the old fashion nuclear scenario. Got electrons orbiting their parent atom centers. Those electrons are in orbits. This is an old fashioned way of looking at it, because it's a lot woolier than that under quantum theory. But this is the really meant quantum theory. Those orbits can be at higher or lower levels. And so if a photon hits an atom, it boosts an electron up to oh maybe maybe put it a different way, if another particle hits an atom, it can boost an electron up to a higher energy level, a higher orbit. When it falls back, it admits a photon that emits the electromagnetic radiation. And so that's how that's one mechanism by which they are four. How does it behave? Well, it travels in straight lines normally in a gravitational field, it might bend because we know that space bends light as the space is distorted. How common is it on other planets? Well, other planets are probably bathed in the electromagnetic radiation from their parents stars. So are we as are we? That's right, we see it all around us. I'm watching it at the moment. A few clouds in the way, but there's electromagnetic radiation coming from the Sun. Do galaxies as a whole have electromagnetism, Yes, they do. We now have the wherewithal with sensitive detectors. In fact, I know one of the astronomers who's built one of these sensitive detectors sensitive to one part in a million. Andrew. It's extraordinary. He works at the University of himself Wales. You speak calling good mind at the end Australian observa treature, I mean Bailey. So he builds what are called polarimeters, and a polarimitter is something that takes light but can sense how it's polarized. And most of us are familiar with polarized light, with the polarizing sunglasses and things of that sort. His polarimeter is, as I said, it's kind of like a pair of polarizing sunglasses. Stif it parts in a million, which is quite incredible. And what that looks at is the way, for example, the way light interacts with dust particles in a distant galaxy, for example, and those dust grains are often aligned by magnetism. So if you've got a galaxy that's got a magnetic field, it will actually show up a polar emitter will show up the magnetic field around it by the way way that the light from it is interacting with dust grains surrounding the the you know, the galaxy itself. So we we've mapped the magnetism of galaxies really quite accurately. By we, I mean the astronomical community. What happens to a planet that doesn't have it. Well, our planet's magnetic because it's got an iron core, and we think that Mars might well have an iron core, but it's kind of static. It's just not hot and swishy like ours is. So Mars doesn't have a magnetic field, so you don't have the protection from radiation from the Sun because you don't have a you know, a magnetic field that actually deflects that radiation. So that they're very quick and glib answers to that list of questions you sent, really and I hope they help because electromagnetism is everywhere. It's one of the fundamental forces of the universe, and we probably couldn't do without it, certainly not here on Earth, because it would be well douarded by radiation from the cell that would not be doing us any at all. No, not really, Probably impossible for life to develop in an environment like that, I would imagine, maybe, so yes, yeah, yeah, all right, Thanks Rennie. And our final question today comes from Ron. I like this one. I didn't like any of the others. No, of course I did. If scientists in a distant solar system were searching for exoplanets using the same technology that we are using, and if they were to observe our planet, would they be able to tell with any degree of certainty that there was life here? Or conversely, if we were to observe an exoplanet that's exactly like Earth, teeming with carbon based life, and perhaps with an advanced civilization modifying their atmosphere, could we tell that there was life there? Thanks Ron. We've had variations of questions like this, but I always like revisiting it because let's say somebody out the squidions of miles away put points a telescope at us, you know, the John Webster space telescope, let's call it. Would they be able to tell that there is life here. The answer is yes, yeah, I thought it would be yeah, and with and that's because of the you know, the signature of living organisms in the atmosphere, and in the case of Earth, that we call these biomarkers. So the biomarker would be oxygen, which is sort of out of balance with carbon dioxide, and I think methane comes into the equation as well. How to balance with methane, So that the only way that you could get this mixture in the atmosphere is by the fact that we've got life pro this is going on. If you had purely chemical reactions taking place, then you wouldn't get these you know, these mismatches of some of the chemicals that we have in the atmosphere. Not only do we think that's the case, we know it's the case because it's been tested and this is an experiment that's been done many times. You know, the phenomenon that we call earth shine Andrew, what you see when you've got a crescent, really thin crescent moon, you can actually see the rest of the moon dimly illuminated. Yes, yes, yes, yes, not so long ago. Yeah, you would probably see every month because if you're looking at the right time. Yes, that's right. It was Slenado who da Vinci who sust out what was going on there, that what you're seeing is the light from the Sun hitting Earth and then being reflected back to the Moon's surface and then reflect it back to us. Yes, so what you're seeing is second ancel lies, but it's passed through Theth's atmosphere. And so if you with a spectroscope, one of these devices that lets you see the barcode that's imprinted on light by these different chemicals. If with a spectroscope you look at earth shine, you can see the signature of Earth's atmosphere on it, and sure enough you would be able to detect that there is life there, because that signature is revealed by earthshine tells you exactly what we've just been talking about. Are these chemicals imbalance, in imbalance with one another? In balanced? Moreover, as Ron suggests, if you've got an advanced civilization modifying their atmosphere, which we've certainly done, could we tell that there was life there? You could probably tell that there was technology there. One of the signatures which are sometimes to techno markers to look for in the atmosphere of a planet is something like the CFCs, the chlorofluoro carbons, which are created by industrial processes and do end up in the atmosphere. We try to get rid of them, what they call it. One of the other things I think you and I talked about once about detectability was the capacity. I think we've developed technology that would be able to detect radar signals on another world. Was that something we talked about. Yes, that's right. Well, indeed that's true because, for example, the square kilometer array radio astronomy colleagues tell me would be sensitive to airport radar a distance of fifty light years. Wow. You know, assuming that the airports we're using the sense of of radar as we use here on Earth, and that's likely that they might and nearly worlded develop the same way as we have. So the is a resounding yes to that question. And it's one of the principal tools that sorry astrobiologists are using to explore the details of exo planets. And indeed, the gems Web telescope has actually I think probably half a dozen cases, maybe even more, managed to sense the chemical elements in some of the exoplanets that transit across the face of their parent star because some of the light that's coming you know, that's that's coming past the planet, that's transiting across its parents style in other words, that's between the parents style and ourselves. Some of that line is going through its atmosphere, and so you can pick up what the what these chemicals are, and there's various different chemicals that have been detected. Carbon dioxide's world water is another. You know, they are detectable. It's a technology that's still in its infancy because our technology is limited. But once the ELT has come along the extremely large telescopes, which the probably the first one will be the European one, the ELT itself, the European Extremely Large Telescope. Once that comes on stream, then we're likely to see more of this kind of discovery chemical elements in the atmospheres of other star planet which may eventually lead to the detection of an unambiguous biomarker which says, yes, there's life somewhere else. Wouldn't that be amazing? I think it will just as an after postcript there. The unambiguity is the difficult bit because often you can find just purely chemical processes that might create the same thing. So These imbalances are what people look for rather than just saying, oh there's oxygen, there, there must be life. It's got to be in a state of, you know, imbalance with other chemicals, which tells you that it's basically been constantly creating. Something else is going on. Somebody pushed the button, all right. Of course, Just as a side note, the famous Stephen Hawking has always said that we shouldn't reveal our presence in any way or form. He's not He was never confident that alien species would be kind to us. And I throw back to the three body problem, which is exactly what that story is about an advanced civilization that contacts Earth and decides they're going to come here because their planet sucks. And so the basis of the story is they're interrupting our scientific development so that we don't jump ahead of them in the four hundred years it's going to take for them to arrive. Really interesting story, really interesting story. That's why I'm persisting with it. I want to know what happens. It's a trilogy, it's a three book story. So yeah, thank you, Ron, that's it's a great question. Always a good discussion point that one, And thanks for every to everyone who sent questions in, and of course don't forget to send us your questions via our website Space Nuts podcast dot com, space nuts dot io. You can click on the AMA tab up the top where you can send us text and audio questions, or the right hand side of the homepage send us your questions. It's audio only. As long as you've got a device with a microphone, you're all set. And don't forget to tell us who you are and where you're from. But we'll take both country and Western questions. Text or audio not a problem. Thanks Freda both. Thanks fred as always great pleasure. Andrew, good to talk. Thanks to all our listeners who have sent stuff in. It's always it's always inspiring and stimulating to look at those questions. It is indeed, fred Wat's an astronomer at large. And Hugh in the studio, thanks for not asking us anything because we don't know anything that you want to know. And from me Andrew Dunkley, thanks for your company again. We'll catch you on the next episode of Space Nuts. Bye bye. Thanks. You'll be listening to the Space Nuts podcast available at Apple Podcasts, Spotify, iHeartRadio, or your favorite podcast player. You can also stream on demand at bites dot com. This has been another quality podcast production from nights dot com.