Hello, and welcome to Ask a Scientist. The podcast for both kids and adults to ask scientists questions about anything they want to know. There are so many scientists out there doing a lot of cool scientific research. In the news, we’re constantly hearing about scientists and their new ideas and where those ideas are going to take us in the future. But just who are these scientists? In this podcast, we will learn a little more about who they are and what inspires them as scientists.
I’m your host, Victoria Crystal. Every other week, I’ll sit down and ask a different scientist questions written by you, the listeners, and by students from classrooms throughout the country.
Victoria:
Hello listeners. Welcome back to the next episode of Ask a Scientist. Our guest this week is Dr. Cara Battersby, assistant professor of Physics at the University of Connecticut.
Dr. Battersby. Thank you so much for being here today.
Dr. Battersby:
Hi Vikki. My pleasure to be here. Thank you for having me.
Victoria:
Before we get started with the questions, do you want to explain a little bit about who you are, what you do, and give the listeners some background info?
Dr. Battersby:
I’d be delighted to. So, I am, as you said, an assistant professor at the University of Connecticut. But way before that, I was a little girl who wanted to be a scientist. When I grew up, I also wanted to be an ice skater and a professional gymnast and a hairdresser. So, I guess one for four or so, isn’t too bad. I grew up in Massachusetts and went to grad school in Colorado, just like yourself, Vikki.
I’ve always been interested in science, like I said, but made me other interests as well. My new latest hobby is I have a new baby at home, a little baby boy. He’s the best. I love him. But in the before times, before COVID, I love to do rock climbing and traveling. I play competitive ultimate Frisbee, and just in general, love spending time with my awesome family and friends.
Victoria:
Well, congrats on the new baby.
Dr. Battersby:
Thank you.
Victoria:
(How do you study how stars are born? What are the different theories about how stars are born?)
Awesome. Well, we can go ahead and get to the questions. All of these questions were submitted by listeners through emails and on social media.
Our first question today comes from Diane. It’s a great question to start off with. How do you study how stars are born? What are the different theories about how stars are born?
Dr. Battersby:
These are very good questions, Diane. We do not know that much about how stars are born. We’re still learning a lot about it.
So let me just start with the first question. So how do we study, how stars are born?
So the process of gas collapsing down in space and forming a star is a very, very, very slow process compared to human lifetimes. So, if we wanted to sit back and watch that happen, you’re talking about, you know, waiting about a million years or so. So that is not how we study how to start this report, because that would be terrible.
We’d never finished our PhD thesis, we never graduate, and we’d be very sad.
So one of the ways that we study how stars are born is that it’s happening all over the sky. I always say with astronomy, it’s not a laboratory science, like some of the other sciences that you learn about, we can’t go into a laboratory and turn a knob and change and experiment. But the great thing about astronomy is that space is really big. And that means that whatever experiment you want to run is probably already happening somewhere in space. So, it’s just your job to find the experiment where the knobs have been tuned the way that you want them to be, and to look there and study those different regions.
So in order to study how stars are born, we can’t watch one individual star go from being a gas cloud all the way down to being a star itself. But what we can do is we can look all over the sky, different parts of our galaxy, and see stars that are being born in different stages, stars of different masses, and then take all these different snapshots of the formation and try to basically reassemble the movie of how the stars are being formed by, you know, using physics and our common sense as well.
And we do this using primarily observations at longer wavelengths, so radio and infrared, but also some optical data as well, all of these different parts of the electromagnetic spectrum, these different forms of light. So using telescopes. And we also use computer simulations.
So your other question about the different theories about how stars are born, for a long time, we just had pen and paper theory. So you just have, sit down with a piece of paper and you look at it and you were like, Hmm, how has this star born? You write down some gravity equations and draw a circle and draw some arrows. And you’re like, oh, it collapses. And you can sort of solve some basic ideas of the physics of how they form. And those kinds of theories were tolerable for a while, but they had some major problems at the beginning. So, one of the simplistic theories of just a large cloud of gas collapsing down under the force of gravity slowly with time and just eventually reaching this very high density, that is a star. If you form stars in that way, you can never form very big stars. You’re kind of limited to something like 50 or 60 times the mass of our sun. And there’s actually stars that are like twice as big as that, really, really big stars. And you wouldn’t be able to make any of them with these traditional theories.
And so theories nowadays, they are done with computer simulations. And so instead of just having a little happy circle that collapses symmetrically under the force of gravity, you suddenly have these complex dynamic interactive systems where you have these gas clouds crashing into each other, spinning around, and no part of it is simple, and simple arrows going inwards. And that is actually how you’re able to form these more massive stars, because you have material continuing to flow onto the star, even in this chaotic system.
So some of the different theories about how stars are born are mostly done with these computer simulations now.
Victoria:
(How long do stars live?)
Cool. That’s awesome.
This next question is from Chris. How long do stars live?
Dr. Battersby:
Excellent question. So, we talked about how long it takes us start to be born, and that can be a very long time, like a hundred thousand years or even a million years. And then how long stars live? It actually depends. For different stars, they live for different amount of time. And there’s one factor that determines how long a star lives, and that is its mass, how big it is. In fact, if you tell me the mass of a star, I can tell you how it’s going to, more about how it was probably formed, what it’s life cycle is going to be like, how long it’s going to live for, and how it’s going to die, which is like very morbid to think about. But like our sun, we know very well how our sun will die because we’ve studied many objects like our sun, but I digress.
So how long has started lives depends on the type of star. And actually, the biggest stars, the ones that have the most mass, they die very quickly. They only lived for maybe 10,000 or a hundred thousand years, probably closer to a hundred thousand years, relatively short.
But then as you get to lower and lower and lower and lower mass stars, they can actually live for longer than the lifetime of the universe so far. So billions of years. There are actually some people who study these really, really low mass stars, that are thought some of the very first stars that were born in the universe, and some of them might still be around today if they were small enough, which is crazy to think about. And a star like our sun, which is about in the middle: we’re not the biggest star, we’re not the smallest star where somewhere in the middle. We live for about 10 billion years. And we’re about halfway through. It’s been a good ride so far.
Victoria:
Yeah. Lots of warm solar rays.
Dr. Battersby:
Yes.
Victoria:
My cat especially loves to just sleep in the sun all day.
Dr. Battersby:
Of course. Mine as well.
Victoria:
(When stars die, do they just burn out?)
All right. This is a good follow-up question from Della. When stars die, do they just burn out?
Dr. Battersby:
Yeah. Excellent question. And an excellent follow-up. So when stars die, it depends completely on the mass of the star.
And so, some really low mass stars, the really, really tiny ones, they do kind of just burn out. I mean, they have a couple of like small little explosions, a few things happen. They might put out a little bit of an emission a mission, but they’re mostly just kind of be boring and quiet and die out.
But other stars, like high-mass stars, they actually go through this wild event. It’s one of the most energetic events in the entire universe called a supernova. And this is when basically the outer layers of the stars fall downwards into the star. It basically the heat source inside the star disappears. And, this is because of the physics of nuclear fusion, which I probably shouldn’t go into too much details of. But suffice it to say, black box of the physics of nuclear fusion, suddenly the thing that was powering the star and holding it together, it goes away. And so you have this huge star that, it just starts to fall in with incredible speeds and force. Imagine if you were just standing at the top of the highest building on the entire planet, and then it just disappeared and you’re just there, you would just start falling so fast. But now, instead of it being you, imagine that you’re like, you know, a hundred times the mass of our sun of material, like falling in, and it actually falls close to the speed of light and then has just this violent explosion. One of the biggest explosions in the entire universe happens when this occurs. And so, this creates huge amount of energy. Most of the material that was in the star gets shot out at extremely high velocities and high energies, and just creates this big, massive, beautiful looking explosion, like a firework. And what’s left on the inside is a black hole or something called a neutron star, which is an exotic form of matter that we don’t understand very well. But basically, when you push together matter with so much force that the electrons and protons can’t stay away from each other, no matter how much they hate each other, you basically change the nature of matter. And it’s a form of matter we’re not that familiar with.
Victoria:
Wow.
Dr. Battersby:
Lots of cool things happen when stars die. Also. Sorry for nerding out so much.
Victoria:
No, this is great.
Dr. Battersby:
In these explosions at the end of a star’s life, it’s actually where a lot of the elements that make up everything in our everyday lives come from. So if there weren’t for stars and their deaths, we would just have hydrogen and helium, and a little bit of lithium in the universe. And that would make for really boring everything. You couldn’t have people, you couldn’t have TV, you couldn’t have sushi. Like there would be, none of those things would exist. And most of the materials like carbon, nitrogen, oxygen, and then these heavier elements were made in the deaths of star, some intermediate mass stars and some high mass stars, and sometimes in the collisions between stars.
Victoria:
That’s so cool.
Dr. Battersby:
Yeah.
Victoria:
That’s awesome.
Dr. Battersby:
Yeah, stellar death is a good thing.
Victoria:
Yeah. I love thinking about it. Cause I, you know, like as a geologist, I talk about minerals all day, iron magnesium, aluminum. It’s so crazy to think about where those actually come from.
Dr. Battersby:
Yeah. It’s wild. It’s really wild. And a star like our sun will form something called the planetary nebula. The central part of the sun will become a white dwarf, which is to get another exotic form of material, but it’s pretty small, pretty boring, no huge explosion. But the outer edge of the sun will probably evaporate the earth and all the and just make this pretty lit up little Nebula for a couple hundred thousand years before it dies away forever.
Victoria:
All right.
And we will have some questions coming up later on about black holes. Lots of cool questions about black holes.
Dr. Battersby:
Yes.
Victoria:
(Are some stars hotter than others?)
But for now, we can talk about some more star related questions. And you’ve talked about this a little bit, I think. Lily wants to know are some stars hotter than others.
Dr. Battersby:
Yeah. Great question. They are, indeed. Some stars are hotter. And I’m going to let you guess what does it depend on.
Nuclear Fusion?
Well, yes, it does actually.
It’s the mass. But the mass determines the nuclear fusion. So you’re totally right. It does depend on the nuclear fusion that’s happening. But how much of that is happening depends on the mass. So all interconnected here. Yeah.
And so once again, the biggest stars, the most high-mass ones, they’re the hottest, and the smallest ones with the coolest.
And if you remember, the high-mass ones, they also die the quickest. So, I like to think of the high-mass stars, they’re like the rock stars of space, because they live fast and they die hard. Sorry. They, how that goes for that?
Victoria:
Yeah. Live fast, live fast, die young.
Dr. Battersby:
Yes. There we go. Yeah, whatever it is. But they burn up all their fuel really quickly. They’re hot, they’re explosive, they do all kinds of cool stuff, and then they die away really quickly. Whereas the low-mass stars are just cool as a cucumber, hanging out in space for several billion years. No big deal.
Victoria:
(Do all stars have planets around them?)
Cool.
Another good question about all stars or stars in general. Zach wants to know, do all stars have planets around them.
Dr. Battersby:
Zach, I don’t know. I wish that I knew. And you know why I don’t know? It’s not because I’m a bad astronomer, it’s because we don’t know as astronomers. We actually don’t know. It’s such a good question. And there are many people in the world who are working on this actively all the time, using some of the best telescopes that have ever been built, and even building new telescopes to try to answer this question, because it’s such an important and such an interesting question.
I will speculate that the more that we look at our stars that are very close by to us, it really seems like wherever we are able to look for planets, we see them. They’re actually seemed to be incredibly common.
And we still don’t have a complete picture of do all stars have planets? Do most stars have planets? How many planets, is it one planet, is it many planets? These are some basic questions that we’re still discovering the answers to. But the initial evidence kind of indicates that probably, probably most stars have planets. And that’s really exciting because even if only a very small fraction of them have life, it really increases the odds that there is other life out there.
Victoria:
(How many stars are in our Galaxy?)
That’s cool.
All right. And another star related question. Aaron wants to know how many stars are in our Galaxy.
Dr. Battersby:
Yeah, good question. This one I can estimate a little bit. So, the general estimate is about a hundred billion stars in our galaxy, which is just one of those numbers that my brain is just like, okay, that’s a big number. I don’t really know what that means. One way I’ve heard it described is, it’s like the number of all the grains of sand on all the beaches of the entire Earth, which is another thing that’s would be hard to estimate how much there is. But I mean, a hundred billion is a really, really, really big number. So I’d say all the grains of sand on all the beaches around the entire Earth. That sounds like a lot. So, I’m going to say that’s a pretty good analogy to consider.
Victoria:
(What conditions must occur for new stars to form?)
Yeah, that does sound like a lot.
All right. Let’s see. And, this next question getting back to how stars form. Kadijah wants to know what conditions must occur for new stars to form.
Dr. Battersby:
Yeah. This is a great question. And honestly, how much time do you have, because I could, I could talk about this for a long time. Well, I think Vikki and I are both going to be ready for bed before I’ve done talking. So let me give you the short version.
Mostly you want to have a lot of dense material like gas and dust and space, and you want it to be as cold as possible. And this happens in space, we have these things called molecular clouds, which are pretty similar to, in some ways, to the clouds that you see in the sky, there’s kind of these amorphously shaped structures. Sometimes they take on interesting shapes if you’re creative enough about how you interpret them. They’re not, you know, strictly spherical or they run the whole gamut. And there’s clouds like this in space that are made of molecular gas molecules. And outside of that region, there’s so much radiation that the molecules just get ripped apart pretty quickly.
And so these are regions that are shielded, and then within those shielded regions, you can get the material moves closer and closer together. And if it’s cold, that means that it’s able to sort of, there’s not too much pressure pushing it apart. And it’s able to sort of slowly collapse under the force of gravity. And so those are the of you want.
You want dense molecular gas and you want it to be cold. So good luck doing that on Earth. And you want it to be a lot of gas too, you can’t just do it in your lab. You have to have like, you know, at least so the lowest mass star is like a 10th of the mass of our sun. You need about that much stuff.
Victoria:
That’s a lot, still.
Dr. Battersby:
Yeah. Cause in order to be a star, you have to be able to engage in nuclear fusion, which means you have to have enough pressure pushing down on you to do that. So. Not something we can do in our laboratory. Very sad.
Victoria:
Oh man, that’d be so cool. If you could.
Dr. Battersby:
I know.
Victoria:
Good thing we have those computer simulations you were talking about earlier.
Dr. Battersby:
That’s right. Yep. They make it all worthwhile, and it’s like virtual reality for star formation.
Victoria:
(Why/how when the Big Bang happened where did the elements from the periodic table appear from?
Oh, that’d be cool.
All right. And then this question, I forgot that this question was coming up when we were talking earlier. Ray wants to know why slash how when the Big Bang happened where did the elements from the periodic table appear from?
Dr. Battersby:
Yeah. So fundamentally like at the beginning of the. I guess there’s two ways to interpret this question and I’m not quite sure what was intended, but they’re both interesting. So we’ll just briefly go through both interpretations.
So one way that I could read this question is that why did the elements of the periodic table that were around when the Big Bang happened? Why were they there? So at the very beginning of the universe, and the Big Bang, there was mostly hydrogen and a little bit of helium and a little bit of lithium. And this is sort of like more fundamental particle physics theory about what was intrinsically just available at the beginning of the universe, not in my expertise, but an interesting question I think. That is somewhat known, there’s some good theories, but probably not definitively known.
Another way to interpret the question though, is like all of the elements beyond those very basic ones, where did they all come from? And this is what we talked about before, a large majority of them came from the death of stars. And these really explosive events like called supernova. We have material crashing into each other at extremely high velocities and just fusing like crazy, and just making all these really heavy, like, you know, platinum and gold, like most of these were made in supernova explosions. And then things like carbon, nitrogen and oxygen, they were made by stars like our sun, or maybe a little bit bigger when they die and give off some of their material. And there’s also when stars and neutron stars and the remnants of old stars crash into each other, you can also get some of these elements being created. But there’s one common ingredient stars and stellar death is responsible for most of these.
And I hopefully you’ve already heard the quote before, but, Carl Sagan, the famous astronomer and science communicator, was popular in the latter half of the 20th century. He famously said that we are a way of the universe to know itself and that we are all star stuff because we’re connected to the cosmos through the elements that make up our own bodies, we’re born inside of the stars. And it’s sort of a really fundamental way of the universe knowing itself is to create humans, we can go there and go back and study the universe.
Victoria:
(Is there anything beyond the universe?)
That’s cool. Awesome.
And speaking of the universe, this is a big question from Max. Is there anything beyond the universe?
Dr. Battersby:
I wish I knew the answer to that. I think, anyone who says that they know the answer to that is lying to you because we just don’t know. I like to think that there might be, but what would that look like? Because when we think about the universe, it’s not just the stuff of the universe. It’s not just some bubble that you’re like, oh, well, there must be something outside of that bubble.
When we talk about the universe, we’re talking about the very fabric of space time.
We’re talking about the laws of physics. Because there are places in the universe that have very little or no material in them, no stuff, the way that we would think about them, but it’s still considered part of the universe. Like what would it mean to have something outside of the laws of physics and something outside of space time. It really stretches the imagination. And in terms of physics, there’s no reason to believe that there couldn’t be other universes. There is no evidence for them. There’s no evidence against them. It’s just something outside the realm of our understanding.
And a way that I think about this is imagine that you’re, so it’s COVID times, right?
So we’re all locked inside. And imagine you were just like locked inside a house and somebody asked you what the color of the house was. You have no windows, what is the color of the house? You have no internet, you have no phone. this isn’t a riddle. I’m just trying to come up with the scenario to sort of give this analogy that you’re on the inside of it, and there’s just no way for you to understand what’s happening on the outside of it. And that’s sort of how I feel about this question. It’s that really wonderful and interesting to think about. And probably not something we’re ever going to have an answer to.
Victoria:
Wow. That’s a good analogy. I like that thinking about outside of my house.
Dr. Battersby:
Yup. It might come up again. Cause I think there were some other questions that talk about parallel universes stuff.
Victoria:
(How could time travel be possible if we only created time as a use of measurement? But if time travel could work, is the only way that it could be is if string theory is real and every possibility parallels to our own world, instead of thinking of time as one line, it’s more of a graph paper, intersecting lines and all connected but not?)
Yeah, yeah. We’ll get there. So, keep that analogy in mind, listeners. Don’t forget that one.
Okay. Now we’ve got a couple of questions from Jamie. So Jamie wants to know about time travel, and how time travel could be possible because we, as humans created time to, you know, put units of measurements to things like hours and minutes. But how would time travel work? And if you could tell us a little bit about string theory and how string theory and time travel might work, if time is like not just one line, but like many lines on a graph paper that run parallel to each other.
Dr. Battersby:
Yeah. This is a lot of there’s a lot going on in this question.
So let me just start with the first piece, which is about time being invented by humans for measurement. And I’m actually going to disagree with that because I think that time was not invented by humans. It’s something that we sort of fundamentally experience. And so we certainly have made seconds and minutes and hours, and we’ve defined what those means, and days and years, but whether or not humans existed, or defined that, time would still exist. And that’s because it’s sort of a, as I said before, a fundamental part of our universe, and I I’ve been reading ahead a little bit. So the next question is talking about time is the fourth dimension. It really is like a fourth dimension of our universe, which we’ll talk about more in the next question.
This question of if time travel is possible. Yes. If you want to go into the future. That form of time travel is possible. And I say that jokingly, but also there are some interesting physics experiments that explore like moving particles into the future, very, you know, nanoseconds, nanoseconds. But in terms of, going back into the past, this has not been done before, as far as we know, it’s not possible. And yeah, I’m not a person who likes to say something is impossible unless I really think it is impossible.
So I’m not going to say that this is impossible. I think it would require a really fundamental change in our understanding of how things work.
One particularly difficult consequence that everything that we understand about the way our universe works, the laws of physics that dictate the universe, they all follow this, like these rules of causality. If you do X, then Y will happen. If I push over this glass of water, it will fall and it will break. And, when you start going back in time, you start to change the causal nature of things. And if you, you know, watch any of these episodes of Star Trek or any other science fiction series, where they try to do time travel, it’s really fun to think about, but for me personally, I’ve never been fully satisfied with the storyline explanation, because there’s just no way to sort of consistently be jumping back and forth in time, because of this causality thing, which like I said, is a fundamental fabric of our nature and the laws of physics.
That being said, though, I think it’s interesting that time appears to only go in one direction. There’s a lot that we still don’t understand about physics. So I’m definitely not going to say time travel is not possible. One fun experiment, I think it was, I don’t want to get this wrong, I think it might’ve been Stephen Hawking or some other very famous physicists said, okay, I’m going to host a time travelers party. I hereby invite all time travelers to come to this party. I can’t wait to meet you, and nobody came. And so that was one way of deciding that, okay, time travel is not possible because where are all of them. Obviously, that’s not a complete, you know, explanation, but I thought it was an interesting theory.
So, speaking of interesting theories, string theory is also super interesting theory.
It’s actually been a while since I’ve read about it, and it’s not something that I use in my everyday you know, research or lecturing in my classrooms, but it’s a really interesting idea that basically instead of the fundamental particles that we’re studying, that the fundamental basic, smallest quantity of stuff in the universe, it’s actually these vibrating strings. And most versions of string theory involve more than the four dimensions that we’re familiar with. They’re really interesting. They’re really elegant. They’re really beautiful. It’s a really nice way to think about the universe as these vibrating strings, like a violin or guitar or something like that. But it’s not proven and it’d be really, really hard to prove, and also really hard to disprove.
And so some people who will work on string theory now their task now is to try to come up with actually testable claims. But these are all really interesting questions. And there’s a good amount of popular literature on some of these topics that I think would be really fun to read.
Victoria:
Yeah. I love time travel stories and like, thinking about the.
Dr. Battersby:
Yeah.
Victoria:
Stephen Hawking thing. I think I was watching a TV show or someone was telling me about a short story in which the reason that people didn’t come to his party is because it kind of getting to like, cause and effects that like if humans at that point in time knew that time travel in the future was possible, it would have caused a bunch of problems and changes. I forget what that was from. I’ll have to Google it.
Dr. Battersby:
Yeah. It’s really hurts your brain if you really think it through, any of these time travel episodes or anything.
Victoria:
(Why are people out there saying “time” IS the 4th dimension? How could that be if us 3 dimensional beings experience it?)
Yeah. but now we can get to the fourth-dimension question that, you know, we’ve been referencing. Another question from Jamie, why are people out there saying that time is the fourth dimension? How could that be if three-dimensional beings experience it?
Dr. Battersby:
Yeah. This is a great question. And the three spatial dimensions, they’re all very familiar with to us. And it’s easy to think about, okay, here’s just a simple line,
line is one dimensional, and then like a plane is two dimensional, and you can stretch that out, and that’d be a third dimension you can think about simply like a piece of paper or something. And you know, the analogy of folding over the papers, like going into another dimension. Those are all very intuitive to us where as the topic of time being a fourth dimension really kind of changes the way that we think about that.
So the way that I think about time as being the fourth dimension is, if I tell you that I’m going to meet you for coffee, you want to know where am I going to meet you for coffee? Let’s meet at the Eiffel Tower. Are we going to meet the North side, the South side, the East side, which side of the Eiffel tower we’re going to meet at?
So we have a very specific three-dimensional location of the position of exactly where we’re going to meet. So, you show up and I’m not there because you need a fourth dimension, you need that time in order for things to intersect in all those four dimensions, you need to have the time access as well.
And so when I talk about myself as existing as a person, I’m a three-dimensional being, but I’m also a three-dimensional being as a function of time because there was a time in the past where it didn’t exist in a time in the future where I won’t exist. And, so really, I am a four-dimensional being, it’s just a different dimension. It’s a different way of thinking about it, which really kind of opens up your mind a little bit about if there were more dimensions like in string theory, those would probably be experienced differently as well.
Victoria:
(Do you think speed of light space travel is possible?)
That’s crazy to think about. Oh my gosh.
All right. Let’s see here. Okay. So speaking of time and space, this next question from Joe. Do you think speed of light space travel is possible?
Dr. Battersby:
Oh, good question. I hope so. That would be so cool if speed of light space travel were possible. I mean, light travels at the speed of light. So I guess I could say it’s possible if you’re a photon or other kind of small particle, there’s this interesting thing in physics where everything that moves at the speed of light is massless, it doesn’t have any mass. So I think there’s a lot about physics that we’re still learning about.
And one thing is that the speed of light seems to be the speed limit of the universe. Like nothing can move faster than the speed of light. And this is the foundation of the theory of special relativity from Albert Einstein. And, if you take the principle that nothing can move faster than the speed of light, then it leads to all these crazy consequences, like if you’re moving close to the speed of light, then sizes can actually contract and time itself can change as well. These things that just sound completely insane, but nope, they’re actually true. They’ve been measured and like way better than science fiction, sometimes what the universe actually does. So special relativity is wild. And it’s all just a consequence of this fact that the speed of light is a constant, and it’s the speed limit of the universe. As far as we know, nothing can move faster than the speed of light.
We also don’t know of anything that can move at the speed of light that has any mass whatsoever. So again, I don’t want to say it’s impossible for speed of light space travel to happen, because there’s so much we don’t understand. But I don’t see how it’s possible. Like there’s no better rocket we can build, there’s no better engine we can build. In terms of physics, as we understand it now, it shouldn’t be possible. But because our understanding is not complete. I wouldn’t want to rule it out. Because also how cool would that be?
Victoria:
That would be so cool.
Dr. Battersby:
It would be so cool. I guess one other thing is when you start traveling close to the speed of light, like I said, the length can actually contract. So you can actually get somewhere like the distance that you’re traveling over. It can like appear to decrease in size. And so, there are some fun tricks like that that maybe could be incorporated to travel faster than we think is possible based on utilizing these kinds of tricks and stuff like that. So who knows?
Victoria:
Oh, that’s cool.
Dr. Battersby:
Warp drives anybody?
Victoria:
(On TV many of the space vehicles have artificial gravity, can that be done in real space craft?)
Awesome. All right.
Let’s see. Well, speaking of TV space vehicles, Aaron wants to know, on TV, many of the space vehicles have artificial gravity. Can that be done in a real spacecraft?
Dr. Battersby:
Actually it can. It requires, you’d have a relatively large spacecraft and it has to be spinning. So if it’s spinning in a circle, I don’t know if you’ve ever done this amusement park ride where it’s like a cylinder and they spin it really fast. If you sort of, you all go to the very edge of the cylinder and then they rotate it. So I don’t remember how, as a kid, it felt like they rotated it so far, like I was like, I’m going to fall out of this thing, but you don’t because you’re stuck to the outside of it like that. You could basically build a spacecraft that is spinning, and then that force of pushing you out constantly could be adjusted, so that feels like gravity. There may be other ways to try to mimic gravity, but none that we are aware of as scientists yet. And this is a really good one. So it just requires you to be spinning.
Victoria:
Cool. Yeah. I remember being a kid and just being completely freaked out by that.
Dr. Battersby:
Yeah, yeah. And that you probably would get sick if it was a small spacecraft.
So I think that’s why it has to be like a big spacecraft. So you don’t just throw up everywhere.
Victoria:
That makes sense, because that’d be pretty gross.
Dr. Battersby:
Pretty unpleasant space, right.
Victoria:
(How many times can a reusable rocket be used? Does corrosion due to friction pay a role and is it worth working on to eliminate it?
Okay. All right. And speaking of spacecraft, Muhammad wants to know how many times can a reusable rocket be used. Does corrosion due to friction pay a role and is it worth working on to eliminate it?
Dr. Battersby:
I love this question. I don’t know the answer myself. I wonder if the answer is actually known because reusable rockets are relatively new phenomena. And so, I think they’re just reusing it as many times as they can, but they haven’t really perfected it, and they haven’t really pushed it to its limit yet.
So I’d say, right now we don’t really know it can be used. I don’t know what’s the most times rocket has been reused, probably only a handful at this point. So I think we don’t know yet.
But your question about does corrosion due to friction play a role, that absolutely probably plays a role in degrading reusable rocket. And I think that they are working on fixing it. It’s totally worth working to fix that.
Victoria:
(What are black holes in space? What do black holes have to do with star formation and star death?)
Cool.
All right. So now switching gears, we said earlier that we were going to get to black holes and here we are. So first to start off with, and you’ve talked about this already, but if there’s any other details or things that you want to add. Zoe wants to know what are black holes in space and what do black holes have to do with star formation and star death?
Dr. Battersby:
So black holes are singularities in space where there is a lot of mass in a very, very small space. By definition, a black hole is a region of space where the force from gravity is so high that not even light can escape it. That’s what makes them black.
So, think about this. If I am standing on Earth and I throw a baseball up in the air, it starts going away from me, but then because of gravity, it comes back down. If I threw a baseball fast enough up in the air, like as fast as a rocket ship, for example, it can actually escape from Earth’s gravity. That’s how rocket ships escape from Earth’s gravity. They’re just moving fast enough that they can actually escape from Earth gravity. Now, can light the escape from the Earth? Yes. Obviously light escapes from the Earth all the time. No problem. It’s the fastest thing in the universe, way faster than a rocket, way faster than a baseball, it can escape from the Earth. No problem.
And so a black hole is the place where the matter is squished down so small, and so densely, that the gravitational force is extremely high and not even light can escape. So hypothetically, if you could be a person and not just a mush of black hole material inside of a black hole, and you shone a flashlight from the black hole out of the black hole, it would not get out of the black hole. It would just turn back around and come back into the black hole.
This is why black holes are so hard to study because we can’t see anything coming from inside of them, because not even light can escape, no information can escape. So what’s happening inside? What’s the physics that’s taking place? I don’t know. We don’t know how to study it. It’s really hard.
And your question about what they have to do with star formation and star death. Most black holes, that black holes come in different sizes. There are some that are about the size of our sun, and those ones were formed by big stars when they died. There are also some black holes that are about a million times bigger than our sun or more. Those ones are called supermassive black holes. And we actually don’t know how those ones formed. They may have formed from a very big star that died, and then continue to grow material, or may have formed in some other way. But we know that they formed very early in the universe. We’re not sure how that they are gigantic and really important for galaxy.
Victoria:
Oh, man. That’s crazy to think about. When you were talking about it and you were like, you know, if we could be in the black hole and shine the light, in my head, I was like trying to picture that, and I was like, oh, the lights, just going to keep going.
And then, no, and we’re talking about a black hole. It doesn’t. That’s like mind-blowing.
Dr. Battersby:
Yeah. So weird.
Victoria:
(Just a thought. If the sun is a sphere and not flat because of the imaging and calculations we’ve done in scientific study. What’s to say because we haven’t completely circled a black “hole” that it’s not in fact a hole but maybe a sphere. And because we only have the perspective from this side of the hole, who’s to say the immense energy suck on the other side is not a sun to another dimension. Now with this mind set what’s stopping us from the speculation that the sun is in actuality just the end of a black hole from another dimension. Mathematically the average energy pulled into a black hole is fairly relative to that which is produced from our sun, correct?)
Yeah. This is so cool. Okay. So now we have another question about black holes. This one’s from Frank. The sun is this sphere and not flat because of the imaging and calculations we’ve done in scientific study. What’s to say that because we haven’t completely circled a black “hole” that in fact the black hole, maybe as a sphere.
And because we only have the perspective from seeing one side of the hole, who’s to say that the immense energy sucked in on the other side is not connected to a sun in another dimension. So with that mindset, if we’re thinking about the black hole on the other side, being connected to the sun of another dimension,
Dr. Battersby:
I can like see your brain melting. Like another dimension.
Victoria:
I’m trying like summarize it. So basically, Frank’s question, is that, is it possible that we are seeing, you know, kind of just this dark hole but then on the other side of the dark hole is actually a sun that’s connected to another dimension, and we can’t see that because we’re only seeing the side that is appearing as a black hole to us?
And mathematically, Frank says the average energy pulled into a black hole is fairly relative to that, which is produced from our sun. Correct?
Dr. Battersby:
There is a lot to unpack here. I will say, first of all, that your first question about whether a black hole is actually a sphere, not a hole, is correct. And that just makes me think that the term black hole is a bad term because it’s not a hole. It is thought to be spherical in shape or maybe sort of flattened, but basically sphere-ish in shape. And so I think that’s just a case where the term black hole is confusing and misleading, and also the way that black holes can be represented in the media, and science fiction literature can be misleading as well. They’re not actually holes that are just sucking material out. They’re just these points in space time where the gravitational force is extremely strong. And as far as we know, they are like spherical, like you said. So that’s really good intuition to take these sorts of misleading ideas and think about it in a way that’s actually totally correct. So well done.
Whether these black hole goes to another dimension or a sun in another dimension? Again, I really don’t know. There is this question of wormholes is just coming up in a second here. But there’s a theory that black holes might be connected to other black holes. And you can have these wormholes that would connect them.
Or you could have a black hole where material falls into the black hole, and then somewhere else in our universe or another universe is like a white hole where all the material comes out of it. And a lot of these series actually do have a mathematical basis as wild as that is like. I’m not going to tell you can travel, especially as fast as the speed of light, or that you can go backwards in time. But like, could you go through a wormhole to another dimension? Well, you probably couldn’t, but maybe some material might be able to.
There’s some surprisingly weird things in physics and black holes are one of them. As I said, we can’t see inside of them. So our understanding of the physics that’s happening is really limited. And there are these exotic, interesting regions. So absolutely worth studying more and thinking about in every way that we can.
I also just want to give one example of people have this idea that black holes are just like vacuum cleaners, that they’re just constantly sucking material. And they’re not all that. And I want to give an example. So if our sun just suddenly decided to be a black hole. Vikki, what do you think would happen?
Victoria:
We’d all be pulled towards it by that gravitational pole.
Dr. Battersby:
That is what most people think. And that’s actually not true. So the sun would shrink down. And so it would no longer be the size that it is now. But, the gravitational force is actually exactly the same. So where we are in our orbit, going around the sun, we would stay, our orbit would stay the same. Everything would be the same, except of course the sun is a giver of all life on or so we’d all die before too long. But besides that, like our gravitational orbit would be the same.
And I’m realizing now that I might’ve been misleading before by talking about the immense gravitational force. And that’s just because it’s so concentrated. So like, if you’re really close to the black hole, the gravitational force is really immense. But if you’re at a distance, like we are, we’re actually pretty far from the sun. Then the gravitational force is just determined by the same laws of gravity that we use to have our own orbit around the sun to stay in orbit, but we wouldn’t be sucked in.
Victoria:
(What are wormholes in space?)
Okay, cool. That makes sense. Awesome.
And now we’ve got that wormhole question that we were alluding to earlier. Chris wants to know what are wormholes in space.
Dr. Battersby:
So wormholes are connected to black holes.
And so it’s this idea that if you have, so this is the case where that analogy with a piece of paper that I mentioned briefly before, if you have a flat piece of paper and you draw a point on one side of the paper and you draw a point far away on the other side of the paper, and you ask someone to draw, what’s the fastest way to get between those two points. Give them a pen, usually they’ll just draw a line between the two points, and think that they’re very clever because they didn’t draw a squiggly line, they just drew a straight line and that’s the fastest distance between two points. And the analogy with a wormhole is that instead of drawing a line on the paper, you actually fold the paper together. So those two points connect.
And so the idea of a wormhole is that because of black holes gravitational force is so strong and so concentrated, it’s actually like the equivalent of in general to be just the new theory of gravity from Albert Einstein. A hundred years old, I didn’t mean to say new, I just newer than Isaac Newton, classic gravity. You’re basically creating like a rip in the fabric of space time with the gravity of the black hole, because it’s such an intense point of pressure.
They use this analogy in general to describe the force of objects from gravity as like you have like a rubber sheets to something that’s like has a little bit of stiffness to it, so it’s not like a bed sheet, but it can also bend and move a little bit. So I don’t know if you’ve been to like a science museum would have something like this. But they, if you put like a heavy ball onto this rubber sheet, it’s going to make like a dimple in that sheet. And so, then if you roll another ball around it, it will actually, you can actually make it orbit around that object. And so this is the analogy for how gravity works nowadays, is that the sheet is actually space time, and these gravitational objects such as stars or black holes are actually just like pulling down on the sheet and changing the curvature of space time. And that is what’s responsible for like the orbital motions that we see.
And so in this analogy, a black hole is actually, it’s not just making a dimple in space time, it’s actually making a rip in space time. And so the idea of a warm hole would be that you could actually, once you’ve ripped the fabric of space time, it could be connected to some other place in space and time somewhere else in the universe.
And that’s the idea of a wormhole. And it would also have to be like a black hole on the other end. Mathematically, there is some theory behind this, there’s no concrete evidence for it whatsoever, but it’s a really interesting idea.
Victoria:
Wow.
Dr. Battersby:
I know, sometimes the things that nature creates are so much wilder than anything or imaginations could ever devise.
Victoria:
Yeah.
Dr. Battersby:
And it’s one of the greatest things about being a scientist, being like, wait, that’s reality, science fiction came up with this other stupid way less interesting idea, but like the reality is that we could actually have wormholes. That’s so much cooler.
Victoria:
(Is there any electricity (millivolts) generated by a magnetic field on a magnet or between two magnets?)
Yeah. That’s awesome.
Okay, so this next question is from Gregory, and this is kind of getting away from black holes and wormholes. This is more about the physics of magnets. And Gregory wants to know, is there any electricity in millivolts generated by a magnetic field on a magnet or between two magnets?
Dr. Battersby:
Yeah. Gregory. So actually, electricity and magnetic fields are intimately connected. They’re considered to be part of the same force, just different manifestations of them. So, like a moving magnetic field can generate electricity, and electricity can generate magnetic fields. They’re intimately tied to one another and you can’t have one without the other. And you can’t understand one without the other.
So indeed, if you have magnets, two magnets, you can definitely generate electricity or vice versa like I said. If you have electricity, you can generate magnetic fields.
Victoria:
Cool.
Dr. Battersby:
Yeah. Magnetism and electricity are really fun to learn about, really fun to play with. I think a lot of us are familiar with some of the basics from just like playing with magnets, as kids mostly. But it’s just so much more than that. And, I don’t know. Anyone who is interested in any of these questions about black holes and stuff I think black holes, they get, there are some aspects of physics that are really popularized as being interesting, but I feel like I’m not sure magnetism is not as popular, but so interesting. It’s really fun to learn about. I mean, I love learning about physics, and just the fact that changing reference frames, you could go from having something that’s electricity, to something that has magnetic fields. It’s really incredible and fun to learn about.
Victoria:
Yeah. I think, sometimes when I think about electricity and like what we can do with electricity, like my computer, you know, is plugged in using electricity, that almost gets to what you mentioned before when we were talking about wormholes, like, what’s real is almost crazier than what you can imagine. Like, I don’t think I could ever imagine all of the ways we can use electricity.
Dr. Battersby:
So true. So true. And we just take it for granted nowadays, but that wasn’t the case, like even a hundred years ago.
Victoria:
Yeah, like I can’t imagine living without electricity and people did it for a long time.
Dr. Battersby:
Yeah. And if you think about like, I always in this podcast, I’ve said a lot of times, Oh, we don’t really know that yet, or we’re still learning about it, like we don’t, our physics hasn’t reached that era yet. You know, only a couple hundred years ago, things like electricity and magnetism were just considered magic. Right. Because there was no physical understanding about it, like physics had no explanation for it. And now we understand them really quite well, doesn’t make them any less interesting, it’s just like more of a solved problem.
Victoria:
That’s awesome.
Dr. Battersby:
(What is your new mission about at NASA?)
All right. And we’ll switch gears a little bit, and talk about kind of some other aspects of your work. So you mentioned in the bio that we gave to some of the listeners, that you had a new mission at NASA. And so, Jane wants to know what is the new mission that you’re working on with NASA?
Victoria:
Yeah. I would love to talk about this. So this is a telescope that we’re proposing, it’s called the Origins Space Telescope because its focus is all about figuring out our cosmic origins as humans. It’s a proposal that we wrote as part of a team assembled by NASA and with help from NASA engineers. And it’s one of four telescopes that were proposed to this big committee that basically will look at all the priorities in astrophysics over the coming decade and kind of prioritize what the most important things to work on.
So the Origins Space Telescope, it would be a far infrared telescope and it would be in space. But it studies our cosmic origins in two ways.
So the first way is by looking at the galaxies of the very beginning of the universe, the first stars that were formed, the first galaxies that were formed. Cosmically speaking, where did we come from as humans? The very beginning of the universe, the first galaxies would be able to study how those galaxies formed, how they evolved and how they came to be the lovely, beautiful, Milky Way disc that we live in today that has had stars that have formed, planets that have formed, and allowed life to develop. So understanding our cosmic origins in the broadest sense.
And the second way that the telescope is able to investigate our cosmic origins is by looking for basically life towards other planets. We are not close enough to being able to determine life. But what we can look for is we can look at the atmospheres of planets that are around other stars, and see if some of the chemicals in the atmospheres are what we call biosignatures. So there’s chemicals that would be considered bioindicators like, oh, there’s methane there that, you know, on the Earth that comes from cow farts and stuff like that. So maybe it indicates that there’s life there. But biosignatures are combinations of elements, chemicals that together cannot be sustained in any other process that is known of except for life. So it’s not just like, oh, there’s methane, but oh, there’s methane plus this other gas. And of course, the exact combinations are escaping my mind at the moment, of course, but there are combinations of molecules that together, if you see both of them in an atmosphere, it means that there’s a good indication that there might be life there.
And this is not something that we can do yet, but it’s something that we could potentially do within about 15-year timescale, which that’s our lifetime. Hopefully for most of you listening to this podcast, hopefully we’re all here in 15 years, and could actually see that in the fact that we’re that close to seeing if there’s these indications of life on other planets within our own lifetimes. It’s a really exciting time to be alive. It’s a really exciting time to be an astronomer. And if we build this telescope, we’d be able to search for life in this way.
The other telescopes are really interesting proposals as well.
Victoria:
(Will you ever go into space?)
Awesome. That is so cool. 15 years.
All right. And this is kind of a fun question from Della. Will you ever go into space?
Dr. Battersby:
Oh, interesting. Will I? I don’t know. It’s unlikely, but maybe. It was certainly not my intention and becoming an astronomer to go into space. There’s some astronomers do apply to be astronauts and get accepted. But most do not. The space program in the U S is a little bit lacking right now. We don’t have our own shuttles. We’re relying on private industry to get people to the international space station. We’re not going back to the moon or other planets right now. So for one, the space program is not particularly booming at the moment. But in terms of the privatization might actually end up being a good thing. You could imagine more people going into space in the future and potentially not just government employees and scientists. You could imagine people going as tourists into space. So I think that there is a possibility that all of us could go into space at some point, myself included. I guess I’m perhaps more likely than the average person.
And would I be interested? I think. I would be interested, but not if it was going to be a very risky endeavor because I love my family and I wouldn’t want to leave them.
Victoria:
Yeah. And I’m sure they wouldn’t want you to leave either.
Dr. Battersby:
Yeah. But maybe we could all go together. So.
Victoria:
Yeah. Family vacation.
Dr. Battersby:
How about Mars this weekend?
Victoria:
(How did you become an astrophysicist? Did you always want to be an astrophysicist?)
All right. And then this is a really cool question that I’m excited to hear the answer to from Kadijah. How did you become an astrophysicist? And you answered this part already. Did you always want to be an astrophysicist?
Dr. Battersby:
Yeah. So I answered already that I’ve always been interested in astronomy. I think since I first heard the words black hole and said, what’s that? And had my first like issue of some astronomy magazine and I was reading about all this stuff. I was like, oh my gosh, so interesting.
I think for a long time though, I didn’t really know that it was a job you could have, like, I didn’t know anyone who an astrophysicist. I don’t even think I knew anyone who was a scientist. So I just didn’t know it was an option to do that. And so I think if I knew it was an option, I would have totally wanted to do that. I know that I wanted to be a scientist when I was little. Let’s see.
But it was many other things that I was interested in. And I think that, I was really lucky to have, you know, teachers and parents who were really supportive of this pathway. And in terms of how did I become an astrophysicist? I would just say, hard work and perseverance. People get this idea that being an astrophysicist, oh, you must just be so smart, you must be so smart. And I don’t think that smartness is something that you’re born with, and it’s just fixed, and either you’re smart or you’re dumb, and that’s just it. I think that intelligence is really all about, it’s fluid, it’s about how much you’re learning, how much you’re growing. So every single day that you’re learning and growing a new things, I think that you’re becoming smarter. And I think that, I personally became smarter than the process of becoming an astrophysicist. I wasn’t an astrophysicist because I was smart, it’s that I worked hard at it. And, that’s what helped me to become a smart person now.
And so I think that part of what allowed me to do that with having supportive mentors and having role models that have encouraged me. Because if you just have this perception that you have to look like this or be like this in order to be an astrophysicist, you’d say, oh, well, I’m not smart enough, I can’t do it. Well, I’m telling you that you can do it. I think that anyone listening to this could be an astrophysicist is just hard work and grit, put in the time, do the problem sets, learn the physics.
And I think that it’s attainable for all of us.
Victoria:
(What do you think about the TV show The Big Bang Theory? Did they get things right? Is that what it’s really like to be an astrophysicist?)
Oh, that is wonderful to hear.
All right. And then this is our last questions, is a kind of fun question. Lily wants to know, what do you think about the TV show The Big Bang theory. Did they get things right? Is that what it’s really like to be an astrophysicist?
Dr. Battersby:
That’s a great question, Lily. So, I have actually seen The Big Bang Theory only a handful of times myself. I thought it was humorous. I definitely laughed. I thought it was funny.
I think that one thing that I will say is that I’m actually tweeted about this because I wanted to ask some of my astrophysicist colleagues what they thought about it. I think the major takeaway for me is that it’s really, it’s perpetuating these stereotypes of like what a scientist can be, like, all of the astrophysicists that are in the show, I think are men, except for like maybe one or two women who appear now and then. Most of them are kind of nerdy. And, they’re not like that dynamic of individuals. And sure, there are astrophysicists that are like that. But I think there’s also astrophysicist who are, you know, one of my close colleagues, like she was a cheerleader for many years, and she’s also an astrophysicist. I know many people who are very social, very quote unquote, like normal people, and they’re also astrophysicists. People who are sporty and they’re astrophysicist. And of course, people who are women, people who are black, people who are of Asian descent, you name it, there’s a lot more diversity in astrophysicists than what is represented on the show.
And let’s see, what did my friends say? They commented on the fact that it leans into these great man notions of science and the idea that, you know, one individual is just so brilliant and they are so important for science that they didn’t really have to behave well, they don’t have to care about their personal hygiene, because they’re just so brilliant. Like you said earlier, Vikki, when we were chatting, it’s this notion of the mad scientist with the crazy hair in the laboratory, and that’s how science gets done. And there are scientists who are like that, but they’re also scientists who have beautiful, well put together hair who wear makeup, who wear high heels. And there’s just a lot more variety. And, science is really not done by one or two brilliant people. It’s done by many hardworking individuals.
And so, I think that these negative stereotypes of scientists and this idea that it’s just brilliance is the most important, those things I don’t agree with. But I did think it was a funny show with cute and lovable character. So I’m not going to totally knock it. I didn’t think it was funny. So.
And is that what it’s like to be an astrophysicist? No. Not for me anyways.
Victoria:
Yeah. Awesome. Well, that is kind of a great note to end on, you know, not perpetuating negative stereotypes of scientists is always something that I’m here for.
But also, you know, it’s nice to laugh at TV shows.
Dr. Battersby:
Yeah.
Victoria:
So, thank you so much for being here and for doing this. And I guess I was sort of kidding when I said that was the last question. I do have one more question and that is do you have any questions for the listeners?
Dr. Battersby:
Oh my gosh. Do I have any questions for the listeners? What is your favorite color? No. What’s your favorite dinosaur? And why? I have another one. Hold on. Hm. If you could name a new object in space, like a cloud or a star forming core, what would you name it and why? If I really like your answer, maybe I’ll try to push for it.
Victoria:
That is a really good one. And do you have a professional social media account or email address that the listeners can reach you at?
Dr. Battersby:
You can find me on Twitter. I’m @battersbot. So just like my name, but instead of Batters B with a Y at the end, it’s an OT like bot like making fun of Twitter bots. @battersbot would be the best way to find me.
Victoria:
Awesome. So listeners can send your answers to the question to @battersbot on Twitter.
Dr. Battersby:
Thanks, Vikki.
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