Latest / Space Nuts: Astronomy Insights & Cosmic Discoveries / #396: Cosmic Riddles & Martian Quakes: Unpacking the Universe's Expansion & Insight's Seismic Secrets

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#396: Cosmic Riddles & Martian Quakes: Unpacking the Universe's Expansion & Insight's Seismic Secrets · Space Nuts: Astronomy Insights & Cosmic Discoveries

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Hello again, thanks for joining us. This is Space Nuts coming up.
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We're talking questions about the expansion of space again, the Insight mission and gravitational
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waves. That's all coming up on this edition of Space Nuts. Fifteen seconds
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guidance in channel ten nine ignition sign Space Nuts NY four three two one Space
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Nuts as when I re bought it, Bills Goods and joining me as always,
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Professor Fred. What's on Astronomer at Large High Fred, Hello Andrew,
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very good to see you again. Now Fred, it is time to talk
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questions and answers from our audience. We've got a few text questions to go
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through today and the first one comes from Nate. Now, this this is
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a question we've had probably many times, but it's worth three visiting because you
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never know what we're going to learn. As we heard early on, things
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can change in the astronomical world at the flick of a switch on the James
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Webspace telescope. So Nate asks, thirteen point eight billion years ago, something
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happened. We know that whatever, whether it was a big bang, the
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big bounce, or a big mac, we know there was an event in
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a seemingly centralized location. My question is if space is expanding What is it
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expanding into or on? Even the singularity? If that's even correct, should
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have been residing in something right. Thanks for making my evenings great. Every
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podcast is listened to the moment it is dropped, and I cherish each and
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every one. You two are fabulous and have been a part of our lives
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since day one. Have a great holiday. We're back and I can't wait
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to hear your answer. Yeah, it's an old chestnut, this one.
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What are we expanding into? Or although he goes, now, what could
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be expanding on? At an interesting angle? Well, yes, yes it
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is. It's a nice additional way of putting it. So I think the
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problem is that we apply our common garden, everyday logic to problems of cosmology
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that don't necessarily work on those logical principles like parallel lines never meeting and things
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like that, which is, actually it is logic, but it's geometrical logic
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of an unusual kind. So the observation that we can make, and I
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guess there's two or three of them, are that refer to relate to this.
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We can observe that the universe has expanding because we've got this signature velocity
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distribution of galaxies, that the further away galaxy you see, the faster it
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is moving away from you, and that's exactly what you will get from space
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that is expanding. We also know that as far as we can see,
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there isn't an edge to it. We can see a horizon, and that
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the easiest one to envisage is the cosmic microwave background radiation, where you're looking
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so far back in time when you look out into space that you're seeing the
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flash of the Big Bang, which is now stretched from light waves to radio
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waves microwaves by the expansion of the universe. So the likelihood is that the
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universe just goes on beyond that. And if we were and there's nothing to
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suggest that's not the case, if we were somewhere else in the universe and
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looked out from our vantage point, which is different from where we are at
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the moment on our galaxy, from somebody else's galaxy somewhere else, we would
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see the same thing, which is cosmic microwave background radiation and lots of galaxies
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all expanding away from us. So the the question about what's it expanding into.
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We don't even know whether that's a meaningful question, because it's actually compressing
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the thing into our own, you know, perception of space and time.
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Whereas there are are possibilities, certainly in terms of the geometry of the universe,
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there are possibilities that might say, well, it doesn't have an edge,
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for example, if you you know, it's like that the idea of
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In fact, this is quite good analogy. Actually, if you think of
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your excuse me, perception of the universe reduced to two dimensions. Now,
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we normally think of two dimensions as being on a piece of paper, a
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flat a flat surface, but it could equally well be on a curved surface
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like a balloon. So if you have your perception of space sitting on the
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surface of a balloon, it expands as you blow up the balloon. And
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yes, in our that you know, that view that we've got, it
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is expanding into an additional dimension, which is the third dimension of space.
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So maybe maybe it will turn out that we will discover that there are hyper
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dimensional spaces within what we've been thinking of as the universe. But maybe the
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universe is just something part of something much smaller. So if you thought,
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sorry, I'm rambling a bit here, Andrew, but we've got a universe
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that's got three dimensions of space and one of time. But if it was
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embedded in a fifth dimension or something in the same way that the balloon is
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embedded in proper space, then it maybe is expanding into something else. That's
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a complex way of describing something quite simple, which is, we don't really
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know, but you know, we think there are possibilities. There are geometrical
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possibilities that would allow that to happen, for the universe not to have an
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edge and be expanding, but to be expanding perhaps in relation to something like
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an additional dimension. We haven't seen any evidence of extra dimensions yet in any
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sense, but there are some various due to people that do believe that that
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may be a possibility. Yeah, and that there are multiple universes as well,
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yes, of course. And what's the other one? I heard?
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That the universe is folding back on itself. That's another one I heard.
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But like a pile of washing, yes, yes, the universe is just
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a massive laundry. Yeah. Well it is a rather dirty place, isn't
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it. I mean it's just full of dust. It's absolutely dusty, dust
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and gas and humans. Yeah, just the mess. Yeah, that's right,
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completely all right, thank you, Nate. The answer is yes,
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it's expanding. It's expanding at an accelerating rate. And what it's expanding into
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we do not know. Lee Stevenson has sent us a question. Hi guys,
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I'm an avid listener since discovering your show around six months ago. You
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are funny and educational at the same time, which one of us. Okay,
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it's a great show. My question is how can we learn so much
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about Mars interior from the Insight mission. I can't figure out how we got
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the knowledge we have from a single point of reference down to the estimated location
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of meteor impact. This has been puzzling me for quite a while, and
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I hope you can explain and educate me. Best wishes. Lee, an
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Englishman in speeding yat was it's not that big a hot from England to Sweden,
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so stopped showing off. Actually I meant to. I meant to.
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I saw this question and meant to check it out. Because of being ill
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for the plus a few days, I haven't really had time. But there
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is some yeah, there there's some very very clever work that's been done by
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the by the Insight team, and I think it involves of course, it
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like all seismology. You know, most seismology, you've got a volcano or
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something that that erupts, or there's something hits the ground, and you pick
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up by a network of seismographs or seismometers all over the planet. This is
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on the Earth, of course, you pick up the echoes of that particular
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seismic event, whether it's a reflection off the core mental boundary, or whether
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it's a refraction past the core. These are all things that you can pick
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up. But it's fairly easy to understand what's going on that you can explore
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the inside of the Earth by having multiple sample points. By that, I
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mean, you know lots of seismographs all over Well, on Mars, you
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don't. You don't have that. You've got one little seismic one little lander
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in sight, which I think I'm right in turning is now defunct. It's
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yes, switching often there last year. It's got one censer. So how
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do you know when you are listening to the seismic signal of a meteorite hitting
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Mars thirteen thousand kilometers away or something like that. But it's a very very
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good question now because I meant to look this up I'm not going to give
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a definitive anti here, but we might we might take that down as a
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bit of homework. And but I'm guessing it may be to do with the
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fact that seismic waves don't just come in one variety. There are if I
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remember these pea waves and S waves. PA waves, I think are pressure
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waves and S waves are sheer waves, which is two different ways that the
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you know, the medium that this is being transmitted through vibrates and it actually
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it's akin to sheer wave will be a bit like a light wave, which
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is a transverse wave, that's what we call it in electromodetic radiation, whereas
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a pea wave will be like a sound wave. Because sound is transmitted by
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pressure mibratish variations in a medium. It's got to have medium to transmit it.
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And I suspect that you can do things with those like the kind of
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things that we do with fast radio bursts in astronomy, where you know that
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the slower, the longer wavelength signals are going to come slower than the higher
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sorry shorter wavelength signals. You otherwise that the higher frequency signals are going to
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arrive first, and that's what causes that dispersion that lets you get the distance
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to something without actually knowing its red shift. You get the dispersion because you
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know, does it transmits as it transmits through what we think of as empty
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space, But it's actually a lot of electrons being very excited, so you
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can pick up information by that. So I'm guessing it's something like that.
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But I will look that up because that's such a good question. And as
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I said, I saw it and I thought, yes, do some research
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into that. It's very clever science though, that they can detect an impact
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so far away and actually isolates its location. That's the thing, exactly the
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point of the question. And Insight did go there with the intent of studying
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the interior of Mars, so it had equipment that was designed to pick up
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these kinds of activities. So that would go halfway to answering Lee's question.
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But we'll put it in the homework homework folder. And for the record,
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Insights mission ended in December twenty twenty two, about fourteen months ago before Give
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or Take Yeah, Thanks Lindsay, Thank you, Lee, and to our
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final question for this episode from Wayne. Greetings, gentlemen, longtime Patreon supporter
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thank you, Wayne, We appreciate it. First time questioner, though,
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what kind of gravitation wave, if any, is generated by a supernova?
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Would these be detectable by late ligo? Love all the horrible dad jokes.
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Keep up the great work. Let's someone then that's one. I mean,
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we do so. They're actually hard to find some of them. Some of
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them are so yeah. I mean I've found thousands, but ninety nine point
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nine percent of them are not airworthy. We must have a different website.
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I don't mean they're rude, they're just so so terrible. Oh yeah,
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so Paulin, Yeah, so yeah, super nova does it make a gravitational
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wave? And as I suppose the question, if I can expand it on
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a bit, is our gravitation waves different according to what causes them? Yeah?
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Well the answer to that is certainly yes. And you know, the
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the things that we can measure with ligo in terms of gravitational ways, it's
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the amplitude and frequency of the wave and the rate at which it decay or
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increases. In the case of merging neutron stars, what you get is this
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chirp where the signal, if you transfer transfer it to audio, becomes up
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because the they're spinning around one another, and then when they actually merge the
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that's the chirp. That's when it goes up like that. But I think,
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and once again I'm sort of dragging out from the bottom of my memories
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of researching into this quite a quite deeply a few years ago. But what
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what what causes? Excuse me? I'll be better when I've started the new
14:43
dose of antibioty, which might be the chemistry. You must really tick you
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off. I tell you, I've never been as ticked off as I was
14:52
when I discovered what it was. Yeah, that's right, Yeah, that
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whatever bit me. Yeah, I'll refrain from showing you what it Oh,
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yeah, thank you because we are on YouTube at the moment. Don't want
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to get banned. No, we don't get banned for showing horrible stuff anyway.
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So just going back to it, So, to generate a gravitational wave,
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you've got to have an accelerating mass, and that's why neutron styles in
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orbits around on another do generate strong gravitational ways because you've got two objects which
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are spinning around each other, revolving around each other, and that basically constitutes
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an accelerating mass now with a supernova, and in a sense we don't know
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that much about these details, but supernova sort of generally speaking, are symmetrical.
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So you have an explosion and you but you have stuff going out in
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all directions which kind of cancels itself out, so you're not really generating a
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huge whatever in the background. I can hear it. I know, I
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know there is. I'm trying to ignore him actually, because he's he's just
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such a pain. Many Marney sent me a cartoon this morning showing a little
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dog dressed in armor with a sword in one hand of shield in the other,
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and it said, how small dogs think of themselves when somebody rings the
16:34
doorbell. That's exactly what he's likes, exactly what He's still only a puppy.
16:41
He's only ten months old, so you've got to give him some you
16:44
know, understanding. Maybe one day he won't do that anymore. Anyway,
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he is definitely an accelerating mass when anybody comes to the door, and will
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probably generate his own gravitational word or so. But just to carry it this
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a little bit further, I have seen the question of whether a neutron star
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itself, which is often the end product of a super and over explosion,
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Whether the neutron star that will be left behind because it's rotating, whether that
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would generate a gravitational wave. But it's because it's only rotating, it's not
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a mass being accelerated, you know, Linearly, it wouldn't unless it has
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mountains on it. And you and I have spoken before about these millimeter high
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mountains. Yes, that neutron stars might have. So if it's got a
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few melometer high mountains on it, then it will generates generate a gravitational way.
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But to the best of my knowledge, nothing has yet been seen by
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Lego or the other detectors that actually represents that. A great question from word.
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You might be interested to know Fred that Wayne is actually watching us on
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YouTube right now, and apparently we've got our YouTube listeners and viewers are pretty
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excited by the fact that Wayne's question happened up happened to be served up right
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now, so that doesn't happen often. So that's really good. Thanks,
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Thanks for thanks for the question, and thanks for watching. Wed. Sorry
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I've got a straight answer, but I'll once again and have a look at
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the details, and so well, it's just a look to all this stuff
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very good, all right, thank you Wayne, and thanks for listening and
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good to have you along live. And if you do have questions for us,
18:40
remember you can send them through via our website Space Nuts podcast dot com
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or space nuts dot io and click on the AMA link to send us a
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The people on YouTube? Don't forget it to subscribe button below. So
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there we go. I've just done it. And that brings us to the
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end of another program. Thank you so much, Fred, pleasure, Andrew,
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good to talk again, and we'll speak again to it we will,
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indeed, Professor Fred Watson, Astronomer at Large getting over his tick bite.
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And to Hugh in the studio who just gets ticked off all the time,
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and from me Andrew Untley, thanks so much. For your company. Looking
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forward to joining you again on the next episode of Space Nuts. Bye Byepacenuts.
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You'll be listening to the Nuts podcast available at Apple Podcasts, Spotify,
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