The Supermassive Podcast - 53: BONUS - Lumpy Space Potatoes

Episode Date: June 21, 2024

In this month's bonus episode Izzie, Dr Becky Smethurst and Dr Robert Massey tackle questions on pulsars, woo woo sounds from black holes, imperfect spheres and alien aurorae. Send your questions to: [e-mail], and we’re also on instagram @SupermassivePod.  The Supermassive podcast is produced by Izzie Clarke and Richard Hollingham and is a Boffin Media production for the Royal Astronomical Society.

Hello and welcome to another bonus episode of the Supermassive podcast from the Royal Astronomical Society with me, science journalist Izzy Clark, astrophysicist Dr Becky Smethurst and the society's deputy director Dr Robert Massey. This is the place where we dive into the Supermassive mailbox which is really living up to its name right now and answer all of your questions. We've also had this amazing message from alex and we've helped him face his fears and i'm very proud of that this is his message he says i just wanted to say that i had a super massive fear of the dentist when i was younger i finally went back to the dentist as an adult and needed some fillings

i listened to your podcast every time i sat in the chair because it's the perfect thing to calm my nerves and gave me something else to focus on. Thank you for what you do and please keep doing it. Well, you're very welcome, Alex. And a shout out to everyone currently listening in a dentist chair with their mouth wide open. I hope this makes you giggle and really confuses your dentist.

Yeah, but then it got me thinking where are the other unique places that people have listened to this podcast so if you are listening to this in a rather unusual place let us know on instagram or you can email podcast at ris.ac.uk right on to the questions uh becky can you help with this one from matt in australia he says hi izzy becky robert and producer richard love the podcast i started listening about six months ago and have finally caught up and i had a question about pulsars do pulsars wobble or are they permanently blasting their rays in the exact same direction thanks so the pulsars don't wobble, Matt, but their magnetic fields do. So pulsars are spinning neutron stars, right? They get formed when stars die and they run out of fuel in

their core. So there's nothing resisting gravity anymore. And the matter in the core gets crushed down. But when that happens, the pulsar inherits the spin of the star that formed it so for example like our sun takes about 26 ish days to spin on its axis right but if you're thinking about okay if you take something like the sun something bigger than the sun is what forms a neutron star if you take that and then squish the matter down what happens to the spin is it's like an ice skater like pulling in their arms to spin faster right have? Have you ever seen that as well? Like people do that and then they get really fast. So it's the same thing. So when a neutron star then forms,

it spins so fast, like more than once a second, right? So the jets of radio light that we then see that make a neutron star a pulsar, that we see as, you know, these pulses flashing are generated then by the magnetic field of the neutron star. So as you can imagine, something that's spinning more than once a second is kind of crazy. So it's a very extreme object, right? And as the pulsar spins, the jets do come out of the magnetic north and south pole because it's the magnetic field that generates the jets of radio

lights and if you remember geography lessons about earth right the earth's magnetic pole doesn't line up with the geographic pole right the like the magnetic north isn't actually the north pole of earth right it shifts around right because you've got this liquid inside generating it it sloshes around right and then obviously there's a delay due to the spin and all these sort of things. So Earth's magnetic North Pole is somewhere in Northern Canada. So if you imagine if Earth was a pulsar and there's just this big beam of light coming out of Northern Canada, right? Then as the Earth spins on its axis that comes out of the actual geographic North Pole, then as the Earth spins, like that beam of light coming out of Northern Canada would like trace out like a cone shape, like an ice cream cone shape on the sky. And

that's what's going on with pulsars and why the jets don't just point in one direction and the pulsar like spin around it. And it's why we see these flashes as they act like lighthouse beams across the universe. Amazing. Thanks, Becky robert debbie from wisconsin has this question about space sounds hi all love the podcast and thanks for the bonus episodes it's helping me with the withdrawal from having to wait for each month's main episode question i have seen many videos out there purporting to have audio from saturn or from black holes etc admittedly the black hole one sounds like a bunch of people moaning distortedly into a microphone and running through with a weird

bunch of effects i.e a pile of bs are these things legit or are they clickbait if legit how do they convert data into sounds hope this one isn't too woo woo for you keep up the great work and if you're not sure what debbie is talking about here is what the black hole at the center of the persis galaxy I love that. Is it just me or does it sound like the souls in The Little Mermaid when she goes down to see Ursula? That is all I can think of. And very similarly, the souls in Hercules. It's very, very ominous.

That's a very specific cultural reference there um yeah anyway so yeah debbie um there's nothing really woo woo about it and it's great that you found them and they're really just ways to use what you call sonification so kind of converting data or other things into sound you're using a different sense to understand these phenomena to an extent and also to create works of art, to have an artistic way of understanding the universe as well. And there are loads of examples of this. They come from everywhere, really, from the worlds in our own solar system.

People have done it with the ionosphere of the Earth and the sort of effects we get there. Radio signals from Jupiter and Saturn are really good and you get various chirps and whoops there. And then one of the famous one is the chirp of the first detection of a gravitational wave right back in 2015 that was you know much touted at the press conference as the the increase in frequency went up and then what NASA have done and the thing that you're thinking about I think is scans of images as well where they kind of run across it

and they convert the the brightness and colours into intensity and frequency too. So what they're doing when people get this, and it's sort of a visualisation, so taking the data and seeing it as an image, they're taking the kind of colour and intensity and converting it to sound, and that's what they're doing. Or you can also, say, take something you hear at radio wavelengths and convert that into audio too, just as we would with, you know,

kind of a many many other things and you might have to adjust the frequency a lot it might be really high pitched or really low pitched and you have to bring it into the the range that humans can hear it but i think it's completely legitimate it's another way of understanding the universe around us so nothing woo-woo about it you can be completely unabashed about watching and listening to these things and the perseus one that Izzy played, that one I think actually technically is sound waves. Sound waves in like commas there, because I mean, it was sort of like a shock wave that was discovered by the Chandra telescope,

sort of through the hot x-ray gas around this black hole. So technically you could turn that shock wave again into a sound wave and then pitch it like you said, Robert. But I love about these things is that you know I've got so many colleagues that are perhaps visually impaired in some way and I feel like obviously astronomy is this science of images but sonifying data or even like this these projects that 3D print images of galaxies or other images in the universe so that people who are visually impaired can engage with astronomy is just amazing and I think people are so clever for the ways that they think up that we can do this. It's great. Totally, totally agree with that.

Okay, and Becky Loderre has been in touch and says, Hello, I was listening to the recent episode about quakes and Dr. Becky's explanation of how Earth's moon was formed got me wondering, what holds the material that coalesced to form it together? And assuming that is how rocky planets and moons are formed, what holds them all together? I understand gravity is what is causing the coalescing of material, but what is it that holds the material together as well? I hope everything's well with you all. Cheers. Thanks, Loda. I mean, it's still gravity holding everything together. Yes, okay, everything comes in and coalesces under gravity. But then once it's there,

it's held together with gravity as well, especially as objects get bigger and bigger, gravity gets stronger, it can start to round things as well. So they stop looking like lumpy potatoes and start looking like planets and moons. So yeah, I mean, that sounds like a boring answer, Loda, but I think it's just gravity unless i guess you're asking about what physical forces then hold atoms together in which case on those scales you're talking about the strong force which is another one of the four fundamental forces in physics that holds together like neutrons and protons like in the the nucleus of an atom so i guess it's a little bit of both of those things and then of course any other forces you have to like hold together molecules and things like this like you know

like ionic bonding and covalent bonding but then i feel like we should ask a chemist i mean we don't have one of those on the team none of us isn't either an astrochemist either but you know speaking of lovely potatoes i always laugh if you look at the actual size of Earth. It is not this perfect sphere. No. You know, most planets are kind, almost rocky planets are a bit lumpy potato-esque. There's basically no perfect spheres in astronomy, pretty much.

I mean, you know, yeah, I'm just thinking black holes, you know. Nothing is perfect. It's all slightly beautifully imperfect and irregular yeah i love it we had a visit at the department the other day in oxford from professor adam burrows who was giving like a lecture and he's really into both like supernova and planets and i we were sort of having coffee with him as sort of like the the postdocs do and stuff like this and we were saying to him how did you go from like one different field of astronomy of supernova like into studying planets and he went well i just really like spheres to be honest that just really made me laugh and we were all there like but technically

they're not really spheres are they like actually they're like spheroids but i think he was he was just joking that basically i think the physics is kind of the same whether you're looking at something that's star sized or planet sized. I feel like we're going to get a lot more questions about this. Anyway, moving on to the next one. Robert, can you help with this question about Aurori? moons in our solar system experience aurorae also could jwst detect the presence of aurorae on exoplanets and would that help us better understand the chemical composition of their atmospheres yeah that's that's a really good one um well at the very least i mean we obviously see aurorae on earth because many of us saw those a few weeks ago many of us fantastic display i know i wasn't trying to wind up busy there i promise

you know yeah your time will come again is he i promise but at the very least we see them on actually loads of places in the solar system so that they're seen on on venus and mars and jupiter and its moon io and uranus and neptune all of those now they're seen in different ways um the aurora on venus they're sort of fairly faint flashes and on mars they're seen in different ways. The aurorae on Venus, they're sort of fairly faint flashes. And on Mars, they're associated because Mars doesn't have a global magnetic field like the Earth. It had one once and what you've got left are magnetized rocks. And where those rocks are strongly magnetized, you get localized aurorae. So they appear over the whole planet.

And then you've also got Jupiter and Saturn and the gas giants and the ice giants, Uranus and Neptune. They have really big displays. The ones on Jupiter and Saturn and the gas giants and the ice giants, Uranus and Neptune. They have really big displays. The ones on Jupiter and Saturn are quite bright. And I think the prominent ultraviolets that were seen by the Hubble Space Telescope, and now there are JWST images of at least the ones around Jupiter. And they're now going to look at Saturn and Uranus and Neptune too. And those are a bit fainter, but they give out radio emission as well. So we know they're there. So they're really widespread through the solar system, wherever the sun's influence is essentially, and it's sending this stream of particles towards a planet, then you expect that kind of interaction.

And as for exoplanets, yes, that does happen too. And there's a good recent example, which is using a telescope called LOFAR, or low-frequency radio telescope, and it's got these antennae distributed across Europe. And, you know, they're really very sensitive things. They're all kind of flat on the ground, but they work as a big radio telescope. And that found aurorae associated with a planet 26 light years away, fairly close by the standards of planets around other stars, that star GJ 1151, which is a red dwarf star, so quite a small, cool one, much smaller than the sun. one much smaller than the sun and so with sensitive radio telescopes we definitely find aurorae and exoplanets and it's a way of knowing actually that there are planets there and also to a certain extent you're quite right what they're made of how their atmospheres work how their magnetic fields work and how they interact with their stars so the answer is yes lots of northern nights display and is his time will come we're rooting for you is it you know

need to get you off to alaska to do a podcast i mean that would be amazing i'll wait for that you know the christmas specials that sounds good yeah now specifically with jwst because that's a telescope an observatory that's operating at infrared wavelengths it's going to find it a lot harder to see aurora around those exoplanets and that's because they don't have a lot of infrared emissions so in our solar system you know they're much closer, they're brighter and so on. It's going to be a lot easier. By the time you go from, say, hundreds of millions of kilometres to trillions of kilometres to the typical distances to even the nearest stars, it's going to be a real struggle. So we are going to rely on other telescopes like LOFAR, like radio telescopes to do that for us instead. Lovely. Thanks, everyone. And thanks for sending in your questions.

Do keep them coming. You can email podcast at ras.ac.uk. And we're also on Instagram at supermassivepod. We'll be back next time with a Q&A special on black holes. Izzy has finally given me what I've been asking for. But until next time, everybody, happy stargazing.