The Supermassive Podcast - 61: BONUS - Could we capture a primordial black hole?

Episode Date: February 12, 2025

What are the implications on space exploration with a change of president? Did cosmic inflation come before the Big Bang? Are there sonic booms in space? Izzie, Becky and Robert take on your questions!  Keep sending your questions to [e-mail] or find us on instagram @SupermassivePod. 

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 answer your questions. So all these questions have been sent in either by emailing us at podcast.ris.ac.uk or by messaging us on Instagram at supermassivepod. So thank you to everyone who sent us an email about space potatoes. We might have to come back to that at a later date. Oh, I'm so excited with the space potatoes episode.

Right. Let's dive into the supermassive mailbox. So Robert, let's start with this question from Jake on behalf of his clever six year old son. He says, Hello, my son Archie is six and loves all things space. He's asked if sound can't travel in space, would there be a sonic boom if you were to travel faster than the speed of sound? Can I just say I was not asking questions like this at six years old. So well done Archie. Yeah, I mean, me neither.

Absolutely not. No, no. Thank you Archie. That's a brilliant question, actually, as well. And mostly, the answer is no, because you're quite right that space essentially, rather than say stars, planets, things of atmospheres, solids, liquids, and so on, can't carry sound, because you need a gas, liquid or solid where the particles are close enough for that to work for them to be compressed and for a wave to move through them.

They have to interact with each other quite closely, essentially. And a sonic boom happens when something like a plane is traveling faster than sound in our atmosphere, and then you get the shock wave that results. But there are sort of some cases where it happens. And one example I came across was that there's a supermassive black hole in the biggest galaxy in the Perseus cluster of galaxies

250 million light-years away and that was observed by the X-ray Observatory Chandra and it's surrounded by gas and then this shock wave Booms around it, but that then that was sonified So NASA turned that into into sound as a way of interpreting it But it's much much lower in tone than the sound that humans can see so they'd they raise the pitch up by I think it was 57 octaves and incredibly big change and then there are things that are compared to sonic booms although you know I hesitate to to make the comparison so one was observed by ESA's infrared Herschel observatory and that was in the the Aquila net dust cloud complex about 800 light years away and that has these filaments and they result from shock waves

where material, in this case, some exploding stars, so supernovae are slammed into the gas. So it's not really comparable to the kind of sonic boom you'd hear on Earth, but there are these sort of shock waves we've seen space in certain circumstances, particularly where you get, you know, these clouds of gas and dust and where you get exploding stars as well. But again, we wouldn't hear anything. So Archie, you're quite right. It's unlikely you're going to get a sonic

boom and certainly not one you're going to hear. Thanks Archie. Okay, Becky, Bruce has sent in this email and says, big fan of the Supermassive podcast here. I am hopelessly confused. Perhaps you and your colleagues can set me straight. Is it the consensus among cosmologists that cosmic inflation preceded the Big Bang? I've read articles stating that the Big Bang occurred first and other articles suggesting that cosmic inflation occurred first. If inflation occurred first, then what are the attributes of the Big Bang that distinguish it from inflation? Here's hoping you can shed some light or cosmic background radiation on the subject. Thanks. Thanks, Bruce. Now, I think this might be a language confusion amongst astronomers, article writers, the public, et cetera, rather than a science misunderstanding here. So everyone

say it with me, space is hard, words are harder. So the Big Bang Theory is everything, right? It's often used though, in language, to mean that sort of time equals zero moment of creation that people colloquially use it to mean. But actually the Big Bang Theory encompasses the universe starting hot and dense in a singularity, expanding out from there rapidly with cosmic inflation, the first stars forming the first galaxies, the expansion of the whole universe, the switch to accelerated expansion, right? It just describes the whole of the 13.8 billion years

of evolution of the universe, right? That is what we mean when we talk about the Big Bang Theory. And so cosmic inflation is part of the Big Bang Theory. And if we were going to be precise here with timings, we think that cosmic inflation happened in the first 10 to the minus 32 seconds. So nought point and then 31 zeros and then one seconds into the universe's lifetime. And so I guess in your question, if you were thinking about the use of the term big bang colloquially to mean like t equals zero cosmic inflation happened after the big bang, but

the big bang theory is actually everything. And that is how the term should be used. But as language evolves, as it does, things get confused. And as I said, there's that sort of disconnect with how astronomers use it and how journalists and the public and people who report on this use it as well. I think a good litmus test for anything, if you come across this kind of thing of confusion, is to know it's not even possible to ask what's before the Big Bang. And I mean that in both senses, the astrophysical sense and then the colloquial Big Bang sense as well, because time and space also began when the universe started expanding in the Big Bang theory,

right? This t equals zero moment. So there was nowhere and no time before Big Bang. So it's not even possible to use the word before because by using it, you're saying that time exists, right? And that you have some access in time that you can go, but time didn't exist before then. So there is no concept of a before to even ask the question about, right? So that's a good litmus test for things like this that come up in the future, Bruce.

And that is where the headaches begin. Yeah, yeah, he's like, can we move on now? We're like, no, I love it, but it's just a big thing to wrap your head around. Yeah. It's time it didn't exist. Well, right, because we can't wrap, I love it, but it's just a big thing to wrap your head around. You're just like, it's time this didn't exist. Well, right, because we can't wrap our head around it because the concept of nothing and no time

and our human brain just, we can't comprehend it. Yeah, it's like, no, no, don't be silly. No, no. You're like, how do you do this as an astrophysicist? I'm like, with maths. I don't picture this in my brain. The maths just tells us that that's the thing. Yeah.

Okay, Robert, here's a question from Christopher Gotch on email. Good evening, Dr. Becky Izzy and Dr. Massey. My question is this, what are the likely implications on space exploration as a result of the change of a White House occupant? Many thanks. It's going to add to our headaches there, I think. Deep breath. Yeah. Thanks. It's going to add to our headaches there, I think. Deep breath. Yeah.

I mean, we started this podcast during the last year of Donald Trump's first term in office in 2020. So in some way, we've been here before. My own views are not exactly secret on that. If you just Google me at leadership council, you'll find those out. But I'm going to try and put those two on side a bit. So I think the honest answer is that scientists in general are probably a bit concerned about it, quite worried about it, what will happen over the next four years. And I can pick out different

examples, you know, one is that relevant to the RAS, one is the need to tackle climate change, you know, the RAS absolutely recognizes that. And our geophysicists are particularly interested in it. And Trump seems to be just set against that, you know, the drill baby drill stuff, and tearing up the Paris agreement during his first day in office. And then obviously there's Elon Musk, who's responsible for companies that deliver incredible technological innovation like SpaceX, but is also doing things

like launching even more satellites into low Earth orbit, which seems risky for space exploration, given debris as well as ground-based astronomy. Will that be properly regulated now, is the conflict of interest just too great? And I think if you were working for NASA, you'd probably also be quite worried about this department of government efficiency

that Musk is heading up, which is pledging to cut a third of government spending, which a lot of people say is actually probably really close to impossible. And certainly, it's very hard to do that without cutting at least some science, because you just haven't got the flexibility to do it, and space exploration as a result. Especially like blue sky science right? Blue sky science is really at risk exactly. That you can't see like an immediate benefit to. And that's always a risk so obviously I really hope that doesn't happen because the U.S. has done amazing things in exploring the wider universe not

just with you know with space probes and observatories and obviously astronauts as well so set against that presumably SpaceX is now gonna get much more involved in US led exploration, the moon and Mars, because that was in the inaugural speech. And using Starship rockets, I guess. So, you know, although it's not the first time, it's now a national goal once again to send people to Mars

and we'll see how that plays out. It's not gonna happen in four years. I think we can safely say that's essentially impossible, wouldn't it? Whatever is said. And as for the rest of the world and how we react to it, well, I mean, the UK and the European Space Agency, at least, collaborate with China, despite, you know, obviously enduring concerns about this attitude

to human rights and the way things work there. And the US is still just about working with the Russians to support the International Space Station. So I don't think we'll see an end to that transatlantic cooperation. But I think it'll be compromised. And I think it'll be a rocky few years ahead. You know, look, if the first day is anything to go on, then depending on when you're listening to this the first few weeks, then yeah, this is going to be challenging. You know, I don't think it'll bring US science to an end or US space exploration to an end, but it's going to take a very different direction. And a lot of us will have real concerns about that.

Yeah, I was just about to say, for context, we are recording this the day after Trump's inauguration. So who knows what will happen in the few weeks between recording this and the episode going out. And we still don't really have an answer for the fact that if Musk is part of Trump's like advisory staff, I don't think he's an official position in government weather, but is there a conflict of interest? Well, SpaceX obviously are a company that are hired by NASA to send stuff into space and they are a government funded Institute, right? There's a clear conflict of interest. Yeah. It's the biggest imaginable conflict of interest, isn't it? Really? I just, yeah,

that's for them to resolve or not, but it's huge and it does skew the way NASA operates. them to resolve or not, but it's huge and it does skew the way NASA operates. Yeah, exactly. And that's what I think I worry about. Surely that has to be addressed. I worry about cutting of science funding and I worry about conflict of interest with NASA's plans going forward for various different missions that might have to have stuff completely rearranged to launch on ESA rockets or whatever because there's a conflict of interest with SpaceX and that all goes through, you know, whatever the bureaucracy of that. So we'll see.

And also the just the cooperation that goes into space exploration that is needed and those, you know, open discussions or shared discussions. And the fact that no one should take ownership of space exploration. I just think all of those are quite big concepts to bring to the table. Also one other thing as well, as we should mention, is also that we had a declaration yesterday that according to the US government, there will only be two genders that are recognized. That will obviously include any government department, including NASA. So I also very much worry about, you know, sort of like any non-binary colleagues and things like that,

that, you know, are they going to feel safe working in this field anymore when we want to welcome them so much and be allies and yet, you know, from the top it's coming down that, you know, they can't exist in that space as they wish to. So it's very, very frustrating just from a human aspect as well. Aysel, quite. And you know, there are, there are many other things I could say, but they're out with the remit of this podcast, I think. But buy me a drink somewhere if you need me and I'll happily tell you.

Okay, let's stop talking about politics now, even though it really affects science. Okay. Exactly. Okay. Well, Becky, Sarah Barrett has sent us a lovely message. Thank you, Sarah. It's a really nice little message. That's what we need right now. Hello Izzy and Becky. Absolutely love the podcast and slowly making my way through the back catalogue. Hearing women's voices in astronomy is so important and you ladies absolutely rock. Thank you. I am sure that 90% of questions you receive are about black holes.

I'm so sorry to add to the pile with a few more. Never apologize for that Sarah. I've been thinking about this all week and hoping you can shed some light. My questions arise off the back of an article which mentions the possibility of tiny primordial black holes. Black holes the size of an atom but the mass of an article which mentions the possibility of tiny primordial black holes, black holes the size of an atom, but the mass of an asteroid, approximately 10 billion to 100 million billion metric tons. So I'm wondering what is the event horizon of a black hole this size? And could we in theory, if we had a large enough receptacle, capture one. Thank you for your time. Off to listen to more episodes now. Thanks Sarah. So, I mean, okay, let's, let's cover, catch everyone up on Primordial Black

Halls first of all. So Primordial Black Halls, Primordial, it's in the name means early universe, right? So they're thought to have been formed in the very early days of the universe. And this is not from like, you know, the way that we know that we can make Black Halls now, right? As you know, star lives, dies, goes supernova, collapses down. If it's heavy enough, it becomes a black hole. Instead, these primordial black holes were thought to have formed from just random fluctuations of matter getting denser and then underdense. And when it was dense enough, maybe for, you know, light not to be able to escape, then a black hole formed, right? So I should start out by saying primordial black holes formed in this random fluctuations way, completely hypothetical still, right? So I should start out by saying primordial black holes formed in this random

fluctuations way completely hypothetical still, right? We have no evidence that they actually exist or not. We've never observed one or proved their existence. It's just one of the predictions that come out of, you know, like the big bang theory and what was happening in the early universe. Unlike observations of black holes in the Milky Way, where we have, you know, accretion around them, and you know, being formed from obviously binary stars that we've gone to, and things like this. So these primordial black holes, their masses can be anywhere from nano kilograms

to like the masses of stars as well, right? And thankfully for us, like with any black hole, the event horizon size is nicely correlated to the mass. It's a simple equation known as the Schwarzschild equation. And I do mean simple. There's like three terms in there and then a two. Like it's not, it's not, I think most people, you know, if you Google that, you could possibly do it. You could work out what, you know, event horizon you would have as if your mass was a black hole. And so with that mass range of black holes, I was just talking about, we're talking about an event horizon range from smaller than an atom to like a few kilometers, right?

Okay. So yes, in theory, like you had to pick it up from a tennis net, you could capture one, right? Cause like fun facts about primordial black holes, like there's always been this thing of that, is there a planet nine in the solar system, right? A planet beyond Pluto that's like skewing all the orbits of like all those trans-Neptunian objects like Pluto and all those kinds of things. And if that was the case, because we haven't found anything with

optical light, so maybe it's a primordial black hole is one idea. If that was a case, it would be about five times the mass of earth, which would make it about nine centimeters across the black hole, right? The size of a tennis ball, basically. So yes, if you had a big enough net, you could capture that one, right? It would just more be the issue of the mass, like of containing it, right? I don't think you would ever want to necessarily capture something like that. But then also, primordial black holes could be a good candidate for dark matter. Do you remember the idea of dark matter, right? Where it's like matter that doesn't interact with light, but we know it's there because of its gravity.

Sounds a lot like a black hole, right? And so if you've got all these black holes that have formed in the early universe, like we're talking like, you know, uncountable numbers of them, I mean, you still got a lot of them hanging around, they would behave like dark matter is observed to behave as well.

So it's an idea that a lot of people are exploring and some things still don't make sense with this idea. There are some things that can't explain, but we're unsure about whether that's our knowledge of primordial black holes or our knowledge of dark matter that's stopping us connecting those dots. Or maybe it is something that rules them out. Is it a dark matter candidate? Who knows? So they're really interesting primordial black holes. And if technically size wise, you could capture one, you'd want to. Okay. And that's it for all of the questions this time. Do keep sending them in the pictures as well and any other requests that you've got the baby names, the pet names. We haven't had pet names

yet. I'm ready for that for 2025. Thank you very much. Yeah. I have a colleague whose dog is called Tycho after Tycho Brahe. And I think that's a great name for a dog. So, you know, I'm just saying we're ready and waiting, but we are, we are. We're so prepped to name your pet. Okay. So you can email us podcast at ras.ac.uk or find us on Instagram at SupermassivePod. We'll be back in a couple of weeks with an episode on sample return missions, which I'm very excited about. But until next time everybody, happy stargazing.