#396: Cosmic Riddles & Martian Quakes: Unpacking the Universe's Expansion & Insight's Seismic Secrets

Hello again, thanks for joining us. This is Space Nuts coming up. We're talking questions about the expansion of space again, the Insight mission and gravitational waves. That's all coming up on this edition of Space Nuts. Fifteen seconds guidance in channel ten nine ignition sign Space Nuts NY four three two one Space Nuts as when I re bought it, Bills Goods and joining me as always, Professor Fred. What's on Astronomer at Large High Fred, Hello Andrew, very good to see you again. Now Fred, it is time to talk questions and answers from our audience. We've got a few text questions to go through today and the first one comes from Nate. Now, this this is a question we've had probably many times, but it's worth three visiting because you never know what we're going to learn. As we heard early on, things can change in the astronomical world at the flick of a switch on the James Webspace telescope. So Nate asks, thirteen point eight billion years ago, something happened. We know that whatever, whether it was a big bang, the big bounce, or a big mac, we know there was an event in a seemingly centralized location. My question is if space is expanding What is it expanding into or on? Even the singularity? If that's even correct, should have been residing in something right. Thanks for making my evenings great. Every podcast is listened to the moment it is dropped, and I cherish each and every one. You two are fabulous and have been a part of our lives since day one. Have a great holiday. We're back and I can't wait to hear your answer. Yeah, it's an old chestnut, this one. What are we expanding into? Or although he goes, now, what could be expanding on? At an interesting angle? Well, yes, yes it is. It's a nice additional way of putting it. So I think the problem is that we apply our common garden, everyday logic to problems of cosmology that don't necessarily work on those logical principles like parallel lines never meeting and things like that, which is, actually it is logic, but it's geometrical logic of an unusual kind. So the observation that we can make, and I guess there's two or three of them, are that refer to relate to this. We can observe that the universe has expanding because we've got this signature velocity distribution of galaxies, that the further away galaxy you see, the faster it is moving away from you, and that's exactly what you will get from space that is expanding. We also know that as far as we can see, there isn't an edge to it. We can see a horizon, and that the easiest one to envisage is the cosmic microwave background radiation, where you're looking so far back in time when you look out into space that you're seeing the flash of the Big Bang, which is now stretched from light waves to radio waves microwaves by the expansion of the universe. So the likelihood is that the universe just goes on beyond that. And if we were and there's nothing to suggest that's not the case, if we were somewhere else in the universe and looked out from our vantage point, which is different from where we are at the moment on our galaxy, from somebody else's galaxy somewhere else, we would see the same thing, which is cosmic microwave background radiation and lots of galaxies all expanding away from us. So the the question about what's it expanding into. We don't even know whether that's a meaningful question, because it's actually compressing the thing into our own, you know, perception of space and time. Whereas there are are possibilities, certainly in terms of the geometry of the universe, there are possibilities that might say, well, it doesn't have an edge, for example, if you you know, it's like that the idea of In fact, this is quite good analogy. Actually, if you think of your excuse me, perception of the universe reduced to two dimensions. Now, we normally think of two dimensions as being on a piece of paper, a flat a flat surface, but it could equally well be on a curved surface like a balloon. So if you have your perception of space sitting on the surface of a balloon, it expands as you blow up the balloon. And yes, in our that you know, that view that we've got, it is expanding into an additional dimension, which is the third dimension of space. So maybe maybe it will turn out that we will discover that there are hyper dimensional spaces within what we've been thinking of as the universe. But maybe the universe is just something part of something much smaller. So if you thought, sorry, I'm rambling a bit here, Andrew, but we've got a universe that's got three dimensions of space and one of time. But if it was embedded in a fifth dimension or something in the same way that the balloon is embedded in proper space, then it maybe is expanding into something else. That's a complex way of describing something quite simple, which is, we don't really know, but you know, we think there are possibilities. There are geometrical possibilities that would allow that to happen, for the universe not to have an edge and be expanding, but to be expanding perhaps in relation to something like an additional dimension. We haven't seen any evidence of extra dimensions yet in any sense, but there are some various due to people that do believe that that may be a possibility. Yeah, and that there are multiple universes as well, yes, of course. And what's the other one? I heard? That the universe is folding back on itself. That's another one I heard. But like a pile of washing, yes, yes, the universe is just a massive laundry. Yeah. Well it is a rather dirty place, isn't it. I mean it's just full of dust. It's absolutely dusty, dust and gas and humans. Yeah, just the mess. Yeah, that's right, completely all right, thank you, Nate. The answer is yes, it's expanding. It's expanding at an accelerating rate. And what it's expanding into we do not know. Lee Stevenson has sent us a question. Hi guys, I'm an avid listener since discovering your show around six months ago. You are funny and educational at the same time, which one of us. Okay, it's a great show. My question is how can we learn so much about Mars interior from the Insight mission. I can't figure out how we got the knowledge we have from a single point of reference down to the estimated location of meteor impact. This has been puzzling me for quite a while, and I hope you can explain and educate me. Best wishes. Lee, an Englishman in speeding yat was it's not that big a hot from England to Sweden, so stopped showing off. Actually I meant to. I meant to. I saw this question and meant to check it out. Because of being ill for the plus a few days, I haven't really had time. But there is some yeah, there there's some very very clever work that's been done by the by the Insight team, and I think it involves of course, it like all seismology. You know, most seismology, you've got a volcano or something that that erupts, or there's something hits the ground, and you pick up by a network of seismographs or seismometers all over the planet. This is on the Earth, of course, you pick up the echoes of that particular seismic event, whether it's a reflection off the core mental boundary, or whether it's a refraction past the core. These are all things that you can pick up. But it's fairly easy to understand what's going on that you can explore the inside of the Earth by having multiple sample points. By that, I mean, you know lots of seismographs all over Well, on Mars, you don't. You don't have that. You've got one little seismic one little lander in sight, which I think I'm right in turning is now defunct. It's yes, switching often there last year. It's got one censer. So how do you know when you are listening to the seismic signal of a meteorite hitting Mars thirteen thousand kilometers away or something like that. But it's a very very good question now because I meant to look this up I'm not going to give a definitive anti here, but we might we might take that down as a bit of homework. And but I'm guessing it may be to do with the fact that seismic waves don't just come in one variety. There are if I remember these pea waves and S waves. PA waves, I think are pressure waves and S waves are sheer waves, which is two different ways that the you know, the medium that this is being transmitted through vibrates and it actually it's akin to sheer wave will be a bit like a light wave, which is a transverse wave, that's what we call it in electromodetic radiation, whereas a pea wave will be like a sound wave. Because sound is transmitted by pressure mibratish variations in a medium. It's got to have medium to transmit it. And I suspect that you can do things with those like the kind of things that we do with fast radio bursts in astronomy, where you know that the slower, the longer wavelength signals are going to come slower than the higher sorry shorter wavelength signals. You otherwise that the higher frequency signals are going to arrive first, and that's what causes that dispersion that lets you get the distance to something without actually knowing its red shift. You get the dispersion because you know, does it transmits as it transmits through what we think of as empty space, But it's actually a lot of electrons being very excited, so you can pick up information by that. So I'm guessing it's something like that. But I will look that up because that's such a good question. And as I said, I saw it and I thought, yes, do some research into that. It's very clever science though, that they can detect an impact so far away and actually isolates its location. That's the thing, exactly the point of the question. And Insight did go there with the intent of studying the interior of Mars, so it had equipment that was designed to pick up these kinds of activities. So that would go halfway to answering Lee's question. But we'll put it in the homework homework folder. And for the record, Insights mission ended in December twenty twenty two, about fourteen months ago before Give or Take Yeah, Thanks Lindsay, Thank you, Lee, and to our final question for this episode from Wayne. Greetings, gentlemen, longtime Patreon supporter thank you, Wayne, We appreciate it. First time questioner, though, what kind of gravitation wave, if any, is generated by a supernova? Would these be detectable by late ligo? Love all the horrible dad jokes. Keep up the great work. Let's someone then that's one. I mean, we do so. They're actually hard to find some of them. Some of them are so yeah. I mean I've found thousands, but ninety nine point nine percent of them are not airworthy. We must have a different website. I don't mean they're rude, they're just so so terrible. Oh yeah, so Paulin, Yeah, so yeah, super nova does it make a gravitational wave? And as I suppose the question, if I can expand it on a bit, is our gravitation waves different according to what causes them? Yeah? Well the answer to that is certainly yes. And you know, the the things that we can measure with ligo in terms of gravitational ways, it's the amplitude and frequency of the wave and the rate at which it decay or increases. In the case of merging neutron stars, what you get is this chirp where the signal, if you transfer transfer it to audio, becomes up because the they're spinning around one another, and then when they actually merge the that's the chirp. That's when it goes up like that. But I think, and once again I'm sort of dragging out from the bottom of my memories of researching into this quite a quite deeply a few years ago. But what what what causes? Excuse me? I'll be better when I've started the new dose of antibioty, which might be the chemistry. You must really tick you off. I tell you, I've never been as ticked off as I was when I discovered what it was. Yeah, that's right, Yeah, that whatever bit me. Yeah, I'll refrain from showing you what it Oh, yeah, thank you because we are on YouTube at the moment. Don't want to get banned. No, we don't get banned for showing horrible stuff anyway. So just going back to it, So, to generate a gravitational wave, you've got to have an accelerating mass, and that's why neutron styles in orbits around on another do generate strong gravitational ways because you've got two objects which are spinning around each other, revolving around each other, and that basically constitutes an accelerating mass now with a supernova, and in a sense we don't know that much about these details, but supernova sort of generally speaking, are symmetrical. So you have an explosion and you but you have stuff going out in all directions which kind of cancels itself out, so you're not really generating a huge whatever in the background. I can hear it. I know, I know there is. I'm trying to ignore him actually, because he's he's just such a pain. Many Marney sent me a cartoon this morning showing a little dog dressed in armor with a sword in one hand of shield in the other, and it said, how small dogs think of themselves when somebody rings the doorbell. That's exactly what he's likes, exactly what He's still only a puppy. He's only ten months old, so you've got to give him some you know, understanding. Maybe one day he won't do that anymore. Anyway, he is definitely an accelerating mass when anybody comes to the door, and will probably generate his own gravitational word or so. But just to carry it this a little bit further, I have seen the question of whether a neutron star itself, which is often the end product of a super and over explosion, Whether the neutron star that will be left behind because it's rotating, whether that would generate a gravitational wave. But it's because it's only rotating, it's not a mass being accelerated, you know, Linearly, it wouldn't unless it has mountains on it. And you and I have spoken before about these millimeter high mountains. Yes, that neutron stars might have. So if it's got a few melometer high mountains on it, then it will generates generate a gravitational way. But to the best of my knowledge, nothing has yet been seen by Lego or the other detectors that actually represents that. A great question from word. You might be interested to know Fred that Wayne is actually watching us on YouTube right now, and apparently we've got our YouTube listeners and viewers are pretty excited by the fact that Wayne's question happened up happened to be served up right now, so that doesn't happen often. So that's really good. Thanks, Thanks for thanks for the question, and thanks for watching. Wed. Sorry I've got a straight answer, but I'll once again and have a look at the details, and so well, it's just a look to all this stuff very good, all right, thank you Wayne, and thanks for listening and good to have you along live. And if you do have questions for us, remember you can send them through via our website Space Nuts podcast dot com or space nuts dot io and click on the AMA link to send us a text or audio question, or just click on the purple thing on the right hand side of the homepage to send us audio. As long as you've got a device with a microphone, you're all set. And tell us who you are and where you're from. We always like to know. And if you're watching this on YouTube, don't forget I've got to do it again. Don't forget to press the subscribe button below. They all do it, are they? The people on YouTube? Don't forget it to subscribe button below. So there we go. I've just done it. And that brings us to the end of another program. Thank you so much, Fred, pleasure, Andrew, good to talk again, and we'll speak again to it we will, indeed, Professor Fred Watson, Astronomer at Large getting over his tick bite. And to Hugh in the studio who just gets ticked off all the time, and from me Andrew Untley, thanks so much. For your company. Looking forward to joining you again on the next episode of Space Nuts. Bye Byepacenuts. You'll be listening to the Nuts podcast available at Apple Podcasts, Spotify, iHeartRadio, or your favorite podcast player. You can also stream on demand at bytes dot com. This has been another quality podcast production from fights dot com.