The Supermassive Podcast - 43: BONUS - Aimless telescopes & beyond the Milky Way

Episode Date: August 11, 2023

Could we detect exoplanets outside of the Milky Way? Could the Euclid Telescope disprove what we know about dark energy and matter? Are we just pointing telescopes aimlessly at patches of space? And is it possible for two black holes to merge and separate into two branches? Izzie Clarke, Dr Becky Smethurst and Dr Robert Massey tackle your burning questions.  Still, have an unanswered question? Send it to [e-mail], tweet @RoyalAstroSoc, or find us on Instagram @SupermassivePod. The Supermassive Podcast from the Royal Astronomical Society is a Boffin Media Production. The producers are Izzie Clarke and Richard Hollingham.

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 Smithers, and the Society's Deputy Director, Dr. Robert Massey. So we've all recovered from talking about darkenergy.matter, everyone. We okay? We've had two weeks to process, you know. Right, so Robert, let's start with this question from glenn booth and he says hi becky izzy and robert i love your podcast and i'm working through the brief history of black holes question given the fantastic growth in telescopes and observatories

like jwst and the rubinatory, do you foresee us being able to detect exoplanets outside of the Milky Way? For example, in satellite galaxies like the Large Magellanic Cloud, or in the local group such as Andromeda? Or is a million plus light years too far away for this to be even remotely possible? Thanks again. Well, the answer, Glenn, is that this has already been done. There's a detection of a planet, and I'm not sure it's the only one either, published in 2021, where if you're aware of one of the ways we detect exoplanets is by when they transit in front of a source. So in our galaxy, missions like Kepler looked at a large number of stars,

and they looked for when the light from those stars dipped down a bit as the planet moved in front of them. So in theory what you need is for that source in a distant galaxy to be bright enough that we can detect it on its own in a fairly unconfused way and see that dip down and it turns out that's already been done in x-rays because certain sources of pump out x-rays and telescopes like the Chandra X-ray Observatory still ticking along is very good at seeing those even in other galaxies. So in 2021, there was a result published where indeed a planet moved in front of an X-ray binary system, and they saw that characteristic dip. But you do need a bright source for it to work.

So in principle, the answer is it can be done. Absolutely, yes. What you're not going to get is any prospect of ever, well, at least in the near future say imaging those particular planets and we can manage that for nearby stars the next generation of telescopes will manage that even better but we're a long way off being able to do that in other galaxies but it does tell us at least that there are planets in other galaxies as well as the Milky Way so not only is the solar system not special in being a star with planets going around it but also our galaxy is not special in having stars with planets around it we can see that from that i think it's reasonable to say

that we know they're distributed across the universe i just also like to add that if this ever does become a thing it will start with incredibly noisy data yes i pity the poor phd student who is tasked when searching for these things in incredibly noisy data of stars very far away with planets that are probably like huge to even make you know a dip in the stars like you know brightness and i just i just can imagine it now and i'm like i'm so sorry to whoever that listeners becky has her head in her hands so i'm like phd imagine like yes it's totally possible do you know when i was doing my phd becky i used to have to sit there and i'm not kidding you with real tapes of data and shove them in a machine stop them getting tangled and switch them around that did that did improve in

a few years but yeah it was just a large part of my life was just backing up data because the local computer didn't have enough space for it someone one of my colleagues andy bunker during lockdown decided that he would digitize all of his observation tapes that he still had in his so he went through that again during lockdown and i was like what a thing to decide to to make yourself suffer through okay becky lodea on instagram has a question about our recent episode on dark matter and dark energy. His question is, I'm a new listener of the Supermassive podcast and I've been enjoying it immensely. Well, that's good.

I heard about the launch of the Euclid telescope and its role will hopefully help us better understand what exactly dark matter and dark energy are. energy are but is there a chance that the observations made by that telescope end up disproving the existence of those things which as far as i understand as a bioinformatics phd student are still hypothetical so they are hypothetical yes but they are the best explanations we have for the evidence we currently have and when i say evidence there is a huge pile of evidence in their favor from the past 50 100 years maybe if you're pushing it back for dark matter and the what euclid is doing by observing you know the positions and the distances of all the galaxies and then making a map of where we find them all and then using the lensing to work out where all the dark matter is that's been done before by many surveys especially ground-based

surveys like you know the dark energy survey for example and you know again that's one of the things that's on the big pile of evidence so the fact that it's sort of redoing the same thing but in space to you know larger distances and a higher resolution than it's done before i don't think that will massively change anything that we've ever seen before i think we're just going to get a much more accurate map that's going to tell us much more about the distribution of dark matter maybe even get some more of its properties is like we talked in talked about in the last episode as well so i doubt anything would change enough to completely rule them out with what Euclid's going to do. However, the universe has been surprising us for a very long time.

Never say never. Never say never. Exactly. So, I mean, this is why we launched these telescopes in the first place. If we knew everything already, if we were sure of everything, we wouldn't be launching Euclid to do what it's doing. So I think the majority of people who work on this would absolutely bloody love it if Euclid completely um like turned everything upside down and gave us something new to ponder over um or at least was like revealed something where we'd never made a connection before like oh actually it's not that it's this I think people would love that but I personally like I'm 98% sure maybe 99% sure that it's just going to give us a you know much better

resolution but a picture of what we already know okay thanks and robert we've had this great question from matthew marshall he says do astrophysicists just point telescopes at random patches of space and hope for the best or do we have a fairly good map of what can be observed and detect anomalies or something or is it both well i just love this i think it's so good it's sort of both i mean look obviously there's a plan when you have observatories and telescopes and you don't just go along and say we're just gonna point it at random bits of the sky however the thing to understand with this is it's building on what becky was saying if you a new instrument or a telescope, you want to try it out on different things. And that's happened for the whole history of the telescope since the first time they were used by Thomas Harriot and Galileo in 1609.

So more than 400 years of this. I think it also applies, actually, if you work in a completely different field, things like a microscope. I mean, if you've ever owned a microscope as a kid, you want to look at different things. It's just what you want to do. Yes. And the same, you know, telescopes do weird things. I'm just like, now? Still? I go to the museums today where they have the microscopes.

I'm like, put it up my head. So, yeah, indeed. So, look, I mean, the example I was thinking of, look, JWST and Saturn. Obviously, they thought, let's point James Webb at Saturn and see what we see. And you've got this beautiful image and then There's the analysis that goes on a result. But there's also an argument for looking at empty bits of the sky as well, or what appear to be empty bits of the sky. And the classic example was the Hubble Deep Field in the 1990s, where the telescope, I think the longest exposure there was looking at it for two weeks. And of course,

what appeared to be an almost empty bit of sky actually was full of galaxies. And it was looking way, way back across the history of the universe so we've seen similar things with james webb as well so we have this it's basically fair to say that with a with a modern powerful observatory wherever you look in the sky you're going to see something so it's not like you're wasting your time pointing it but random well i don't know you know observatories are expensive if you sit there and say i'm just going to point it randomly across the sky your your phd supervisor might tick you off if you were given that level of control but uh yeah so in practice there's a target list but of course i mean you could point it anywhere and i don't doubt with a new telescope you're going to see things

that people have never seen before although we should add like jdwst if you apply to use jdwst and look at a specific object with one of the instruments on board, let's say NIRCAM, which is the imager. The other instruments on board also work at the same time, but they're looking at a slightly different patch of sky, which could be anything. So that technically is pointing at a random patch of sky. And then if people want to dive into that data and see what they find, fine, great, go ahead kind of thing. I guess I could give an example of my research like i use data from a survey to look at huge populations of galaxies and be like cool i can just take what this data is available and then if i find anything weird

is when i'll then apply to a telescope to like follow up on it and the things we can't explain so i feel like that you know it's a bit of both as you said robert that's the example of yeah okay and becky can you help with this one from jeffrey jones he says i feel like that, you know, it's a bit of both, as you said, Robert. That's the example of a bit of both. Okay, and Becky, can you help with this one from Jeffrey Jones? He says, I feel like you're going to answer this question with a big no, but I'll ask anyway. When two black holes, whether normal or supermassive, merge, can they divide into two branches? Would this be an example of something escaping a black hole?

Would any deformation be a problem? Deep breath. No. That was your big no, Jeffrey, sorry. Not as far as we understand the maths. So if two black holes merge, they're singularities. So that's how we explain, you know, what a black hole is mathematically. All the maths, you know, sort of concentrated in that infinitely small, infinitely dense point. point if the two black holes have merged that means the singularities have merged and at

that point we have no way of or at least no no way mathematically that we know of to split anything out of that singularity at that point so that was your big fat no unfortunately i'm sorry i can't give you anything more but that you know the singularities are beyond the event horizon, so we don't know what's going on past there. If it isn't a singularity, it could be some exotic form of matter that all of the mass in a black hole is crushed into. And maybe they merged in terms of the event horizons,

but there's something going on beyond there. But it's complete speculation at that point. And I can't tell you. Robert's looking very thoughtful, so maybe he has more insight on this than I do. He's pondering. he's pondering pondering is probably the limit of my contribution at this point i think thinking about what happens within the event horizon yeah it's just the absolutely unknowable well thank you everyone do keep the questions coming you can email podcast at ras.ac.uk tweet at royal astrosoc and we're also on instagram and threads at super

massive pod and if you could rate and review if you've enjoyed this and that would be a massive help as well yeah thanks everybody who has done already as well it really helps us we'll be back next time with an episode about solar orbiter and the sun you know the one that we promised ages ago and we gave you one on dark matter and dark energy instead sorry for all of those who are big sun fans but until then everybody happy stargazing