Relativistic Beaming, Martian Waters & Cosmic Trash: The Space Nuts Q&A

Hi there, Thanks for joining us. This is a Q and A edition of Space Nuts where we talk astronomy and space science and we answer audience questions or we just say a lot of words that sound like answers, but then they'll check it later on the internet and realized we were just giving them an absolute. Loaded cod swallop. Coming up today, relative lp, you're not supposed to be talking yet. Relativistic relativistic Doppler beaming. What on Earth is that we're about to find out? Sunny has sent us an audio question about Mars water. Is it water? Was it water? Could it have been something else? Holt is asking how much stuff we can send off the planet before the planet sort of you know, starts to fall off itself and fusion reaction in the sun. We will dispel that confusion very very soon. On this episode of Space Nuts. Fifteen, Channel ten nine ignition Space Nuts or three two. Space Nurse and I reported Neil Good. Professor Fred Watson, a storm at large's here. You've already heard his voice. Hello Fred, Nice. To see you. Andrew. I'm always reminded of and you might know about this as well, even though our listeners are all too young to remember. But on the Goon Show there was once an episode where Eccles came on before he was supposed to. I had to make the comment do. I remember that? Yes, I'm. Which reminds me of a famous incident on ABC Radio where I worked for twenty two years, where a news reader was trying to do the bulletin but they were halfway through a live interview with Spike Milligan. Spike kept interrupting at the end of every sentence with and Spike Milligan and Spike Milligans. And so when the story finished, the newsreader said, Da Da Da Da da and Spike Milligan. He got He got fired for that. He got fired for that. It's one of the funniest pieces of radio you will ever hear. Look it up online. But he got canned. Probably yeah, old BBC days, probably, Oh well yeah, probably, well, yeah, the times have changed. Yes, Rather, let's get into some questions, Fred, and I've got our first one here from Ron, who is in upstate New York. He says, springs just around the corner. He says, hope all is well down under? Well, if you like wind, yeah it is, it's going great, and it's been pretty windy here lately. I have a question about relativistic Doppler beaming that we see on a black hole s accretion disc which causes the side moving towards us to be brighter than the side moving away from us. Why are we not seeing blue and red Doppler shifts in the color of the light in those respective regions. There's so much, and thanks so much for the great podcast. It is our pleasure. It is our pleasure. Thanks for the question, Ron, It's. A good question, and there's the answer, Jordy. Yeah, so we do. We do see the Doppler shift. But the reason why we don't talk about that is because this radiation that's being beamed out is a continuum radiation. By that, I mean it's at all wavelengths. So to make Doppler work, just the backstory here. If you've got something coming towards you, it's light is shifted to the blue. If it's moving away from you, it's light it's shifted to the red. But you need a feature in order to detect that. And some sources of light, for example, it actually even works with LEDs does this. But if you think of the old orange sodium lights which we used to see the low pressure sodium lights. They emit all their light at one wavelength, which is called the sodium D line for historical reasons. And so if you had a sodium lamp coming towards you, then that peak of wavelength would be moved to the blue end of the spectrum. If it was going away from you, it be moved to the red end of the spectrum, the sodium line. But in order to so that happens for all moving objects. But in order for you to be able to detect that it's moving, you need a discrete peak of lights or radiation, And in the case of a moving sodium lamp, that's it the peak of the sodium sodium emission line. If you've got a continuum a spectrum that was all the way from blue to red or violet to red, yes, it can be moved by the Doppler shift, but you don't see it, you don't detect it. And so in the case of the material swirling around a black hole in the accretion disc, exactly as Ron says, it actually undergoes something called relativistic Doppler beaming. And because this stuff is moving so fast, it's really not far short of the speed of light, the path of the photons is altered, and they tend to cluster around the direction in which the movement is taking place. And that's why an accretion disc is brighter on one side than it is on the other. It's brighter in the side that's coming towards you because of this relativistic Doppler beaming. It's quite an esoteric topic. I'm quite amazed that we're covering this on Space nuts, but it's really good stuff. Thank you, Ron, because you're clearly very very well versed in this stuff as well. I mean, when you look at the images of black holes that we now have, you're looking at an orange frosted doughnut. Basically, that's that's the primary color, the orange, but it is brighter on one side. This is there are. Blight spots in it, that's correct. Yeah, and some of that will be due to relativistic beaming. Yeah, okay, And how many have they taken now? I think there's been maybe three through. Yes, so we've got M fifty two was the first, is that right? Yeah? Fifty two the center of our galaxy, Sagittaria s a star. But also M fifty two done again with polarization, so we could see the magnetism in it. I think that's the way it worked. Okay, these we were with the event horizon telescope. Because I've got another one here that's of M eighty seven. Okay, that's there is another object that's. Yeah, that's the third one I was thinking of. I didn't know they've done in fifty two. Again, but the technology has reached a point now where we can actually image these things. They're not photos, so are they? These are gathered through radio spectrometry of Yeah. It's basically a planet sized array of radio telescopes that conspire together in very cunning ways to make these images, to synthesize the images. Fantastic stuff. Ron Thanks so much for the question. Really enjoyed that one, and hopefully hopefully we'll hear from you again. Our next question comes from Sunny What a great name for somebody who listens to an astronomy podcast. Hello, Spacenuts, This is Sunny Skies from southern California, Long Beach. In fact, my question for you today is regarding geological formations on Mars, which indicate there was large quantities of water for a long period of time. Similar to something we'd see on Earth. Is there any other corroborative information or data to support that it actually was water and not some other crazy liquid that we don't have here, possibly on Earth? Love the podcast the sunny. We're trying to it's coming into winter here, so it won't be sunny for long, Sonny Lovely to hear from you. That's a good question, because we've got a lot of evidence that shows there was water, rivers, oceans, streams, you know, cestpits, whatever you want to call them, on Mars. But that's all gone, but we are, you know, the telltale signs are there. Sonny's question is was it really water or could it have been something else? We do know there are other liquid. Oceans in our Solar system that are not water. Yes, we do, that's right, and there's more than one kind of water, which is also a fact that it considers. So yeah, could he be onder something or we absolutely did set certain that Mars had water? I think we are water perhaps. Yes, and that's why for that reason we still we can still see it. So and I'll explain that in a second. Yes, I guess gives me. Sonny's point is we see evidence of liquid. Could it have been something peculiar that we don't know about, And. In a way it is because. We have seen evidence on Mars from principally from the Phoenix Lander, which was on the which is near the northern Polar regions, the Northern Arctic of Mars, which actually analyzed chemically some of these materials. So you might remember Andrew Phoenix had a little backo. It was didn't have any wheels, it was stationary, but it had a bacco with which it could scrape away the top surface of the soil of Mars. And it didn't have to scrape much before it got to solid ice. And the first hint that this was ice was in the color it was white. The second hint was that some scraps of this material that had been dug up by the backo basically disappeared after a few days. They had turned directly into vapor. They'd sublimed, and that's exactly what you'd expect for water ice to do. But more especially, that bacho wasn't just there to scrape things. It was to pour the things it had dug up into a chemical analysis. And that's the smoking gun, because the chemical analysis demonstrated that yes, this was water, water ice, solid ice, and that's there in large quantities under the surface of the Arctic regions of Mars. And we know it's there in the on the surface actually in the polar caps of Mars, and we know it's water ice from there because it's got the spectral signature of water ice. But the reason why I say it could be a bit different is that we believe that this water is very briny, that it's rich in what are called perchlorates, which actually lower the freezing point. And there's evidence that for a short time there were droplets of water actually on the legs of the Phoenix Lander, probably made of ice that have been melted during the descent, vaporized, condensed out onto the onto the legs of the lander, and stayed liquid for a little time while the heat was well that temperature was high enough. So all the all the evidence points to those oceans having been made of water. Although it might be very briny, it might be chemically different from from what we experience on Earth. But only to look at the different forms that water comes in on Earth. When you've got some of them where you've got cyanide dissolved in it, in some of these pools, you know, in Yosemite in places like that. So I think I think it's a good question. But I think basically H two O is what makes up the contents of those format oceans. I think what's interesting about Mars water is that it's it's heavier. Than Earth water. It's got a much higher ratio of isotopes, heavy isotopes of hydrogen. I think is which is which is heavy water? Not the stuff ever the nuclear reactors, but natural it is water. Yes, that's right. It's it's similar to what was used in the nuclear reactors. So it's it's hydrogen with an extra neutron. I guess, is that right to make deuterium? And and yes, you're right that the ratio of and once again this comes from analysis by machines like Phoenix. On the surface of Mars, there's a higher ratio of. I think that's the way around. It is a higher ratio of heavy water to normal water on Mars than there is on Earth. I think that's the case. Yeah. And the other thing sunny is you couldn't drink it in its current state. It would need to be cleaned up a bit. Yeah. Do you remember we want to talk about how much heavy water you could drink and still survive, and it's come. It's a fair bit. Actually it was a few percent, yes, but. If you drank it for long enough, it would start you'd start to basically fall apart, literally fall apart, because the deuterium wouldn't your bodies. We're not built for it, basically. Yes, exactly. Yeah, if we were to find a water world that was one hundred percent D two ozer rather than age, we couldn't live there. It would kill it. Even though it's water, it's just it's not our water, heavy water. Yes, yes, So your point is very very good, Sonny. There's a bit more to it than. Meets the eye. And yes it is water on Mars, but it's not the same as our water. It's close, but it's not quite the same. Thanks for the question, and hopefully hopefully we'll hear from you again, Sonny. Great question, that one. This is Space Nuts with Andrew Dunkley and Professor Fred What's a Let's take a break from the show to tell you about our sponsor, nor VPN. Now, if you've ever felt like your online privacy is slipping through the cracks, then you're not alone. Hackers, scammers, harvesters. They're all out there trying to get your private info, whether that's your passwords or your personal details to sell on the dark web, or to use themselves to access your bank account's, credit card details, and who knows what else. But you can protect yourself with nord vpn. You can take control at home or more importantly, when you're out in public using free Wi Fi. Right now, using the exclusive space nuts offer, you can receive four extra months for free on a NordVPN dot com plan. NordVPN encrypt your internet connection, hides your IP address, and offers access to over seven seven hundred servers around the world. Plus with features like threat protection, pro mesh net, ultra fast speeds via nord links, your digital life stays private and efficient, So don't miss out. Visit NordVPN dot com slash space nuts and enter the code space nuts to claim this deal. Remember there's a thirty day money back guarantee, so it's risk free to try, stay safe, stay private, and browse with confidence. That's g nord vpn dot com slash space nuts. Off space MutS. I like this next question from Holt because it's it's it's so simple, and yet it's it's something that people wonder about because we have reached a point where we've been going sending stuff into space for decades now. And he goes on to say, we've sent several objects beyond Earth's gravitational field. How much can we send before it affects Earth's orbit? That comes from Halt. I don't know where you're from, but great question, Halt love this one. Yeah, we're basically filling the universe with our own junk. But all of that stuff that we're sending out there comes off planet in one way or another. So yeah, what could be the long term effect? Yeah, great question. So the figures are and I'm pulling this from my memory, but I think this is right. In orbit, we have something like I think it's about eleven thousand tons of stuff. Is that all? Yeah, something like that. That's with all of the spacecraft that have been launched. To remember, these spacecraft are made of very light materials because you can't you don't want heavy stuff being sent into orbit because you're wasting fuel. The lighter you can make your spacecraft, the less fuel you need. So it's all about economics. But I think it's about eleven thousand tons in orbit, and when you look at spacecraft that have gone beyond that, it's vanishingly small. You know, it's probably less than one hundred tons. It might be about one hundred tons for stuff that's gone out beyond Earth orbit. So that when you compare it with the mass of the Earth, which I can't remember, but it's a lot, it's one earth mass actually in units, and you know, but it's it's gazillions of tons compared with what we've put into space. So it's not going to affect the Earth's orbit, and actually the orbit itself. Even if we put you know, a significant fraction of the Earth's mass into orbit around the Earth, it wouldn't necessarily affect the Earth's orbit because it tends to need an interaction between two objects to change the orbit of something, a clout from another planet or something like that, that would change the orbit, right whereas whereas just doing something that has the same center of mass as the Earth does, if I can put it that way, doesn't necessarily change the orbit at all. But even notwithstanding that, we're we're nowhere near anything that would actually affect the Earth's well being. The mess of the Earth is five point ninety seven two one nine times times tender the twenty fourth pounds kilograms. Yep, ten to the twenty fourth power. Yeah, that sounds right. It's a lot. I big. I think to remember that the sun is something. It's about turns of twenty seven kilograms, I think, or it could be tons. I can't remember, but. It's I can look that up too. Yeah, must have the song. I think it's on one point nine to eight nine times times ten to the thirtyeth power kilograms. That's that's kilograms. Okay, so it's turns to twenty seven tons. Yeah, yep, that's what it now one more than it's one more. Thing that hold might be interested to know is that, you know, you've given us the numbers of how much material in terms of weight, has left the planet, which is a negligible amount, but scientists estimate that roughly one hundred metric tons of cosmic dust like micro meteorites, enters the atmosphere. Every day, every day. That's right, every day. Yeah, so we're actually getting heavier. Yeah, we are all more massive. Depending on which way you want to look at. It, it's more massive, is the correct You might write. To be heavier, you need to be in the gravitational field of something. We are in the Sun's gravitational field, but we wouldn't think of it that way. No, No, So. When you when you think about it, what we're what we're kicking out of our planet, our gravitational field, it is being replaced like. Yes, yes, quite much more. Yeah, exactly, So thank you for pointing that out. It's well, it's about a hundred one hundred, one hundred tons are thereabouts, and it's just meteoritic material, so really usually contributes to the atmosphere because it gets vaporized most of it. To quote a famous Scottish astronomer, it's space. Clap is what it is that I think he used to be on my staff the absolut. All right, great question, made for some interesting discussion and made me sound useful for a brief second. Thanks for sending it in. Our final question comes from Ken Hi. Andrew and Fred Ken from a Rouchi door. Longtime listener and fan, and love the way you make complex issues sound so simple. I'm trying to understand the basic fusion reaction that both me and my accountant are struggling with the basic fusion reaction in our sun and all main sequence stars converts hydrogen to helium to create energy. To summarize a reaction for hydrogen nuclei, that is, four protons go through two steps to create one helium nucleus containing two neutrons and protons. Additionally, gamma raised neutrinos and positrons are released. My astronomy textbooks say that about six hundred million tons of hydrogen are converted to five hundred and ninety six million tons of helium every second in our Sun. The four million tons is converted to energy as per equals mc square. If neutrons had a lower mass than protons, it would make. All perfect sense. But they don't. They have a higher mass, so the mass of the helium nucleus is higher than the mass. Of the four protons. All the explanations I've read sound pretty dodgy, and my account says he could never get away with such explanations with the tax Department. Could you please explain the devil in the detail that I'm missing? Thank you, Kenji. He did his homework on that one, didn't he. Wow. It's absolutely right too, and looks in such a terrible part of the world, they Richie do or what I don't think. I think I think Ken's going to find this answer that I'm going to give him pretty dodgy as well, because but it is the correct answer, because it turns out that unlike Ken's accountant, who can do sort of arithmetic because dollars don't change their mass, you know, randomly, you can't do the same with sub atomic particles because you have to look at other factors. And the factor that comes into being in this case, and I'm sure this is what Ken was referring to when he talked about dodgy answers is something called the binding energy. So he's right that the helium four that's formed by the four hydrogen atoms should have slightly more in mass, should have slightly more mass than the four hydrogen atoms. That's because you're you're doing doing the calculation, begging pardon. It's the other way around. It should should have slightly less mass in order to give you the energy that makes the sunshine. But it actually turns out to be the other way around. And the difference is what I've just called. It's something called binding energy. The difference is the binding energy in the helium nucleus, which is called a mass defect, which lowers the actual mass of the helium nucleus slightly. So what what what Ken's saying is that when you add up the masses of all these particles, you get something that's more massive than what you started, and you should expect it to be less massive than what you started because of that, the fact that you've got this large amount of mass being turned into radiation that's how the sun shines, but in fact it is less than what you started with because of this mass defect. The binding energy, there's an energy that holds nuclei together which actually effectively contributes to their mass because of exactly what Ken said equals mc squared. And I hope you don't think that sounds too dodgy, Ken, But that's the answer. You can and you and your account can relax. Now the numbers do add up. They're just a bit weird. I'm sure she would, and she probably does the same calculation that I had too. It's just that atoms don't behave like dollars do. They change depending on what they're doing. Yeah, my my money X like that sort of implode on each other. They just yeah, that's pretty well, what happens. That's that's called nuclear fission where it leaks away. Yes, that's what it is. Yep, yeah, indeed, so yeah, well done, Fred. I you might have noticed my eyes glazed over when you tried to explain that, but I'm sure can understands because the homework you put into that question was spectacular. Thanks Ken, lovely to hear from you. Hope all is well in that hideous place called Maruchi Door on one of the most beautiful parts of the East Coast of Australia. It's a lovely area, absolutely beautiful. So jealous, I'm going We've got a bit of time up as sleeve. A quick one, Fred, just a question without notice. Actually this comes from Sandy in Melbourne. Good o, Fred Andrew. I was recently watching the live views of the Artemis two spacecraft and there was what appears to be dust going past the spacecraft. What on earth is it? Is it rocks, dust, debris or exhaust material from the ship's maneuvering engines. And he did send a link to a YouTube video of it, and it's just really bright pieces of material just zipping past the spacecraft. I would think exhaust. Maybe have you come across. I need to look at that, which I'm just going to try and do because I didn't have a chat. I've been flutter all day talking about to myself all over the place. For a minute. Where are we? It's an email that I received. Just send it to you again. This is like live radio, Fred. We're just the t's like, we're just doing it on the hob. But it's a fascinating video. I'm just looking at it now and it's only about fifteen seconds. But yes, you can see all these bright flashes just zipping past the spacecraft. It could be exhaust material. I'm not able to see your incoming email. What's what? Who is the. It's from Handy Sandy that No. It must have come via a hang on here we are. Space nuts this. Yeah, okay, all right, I've got the link. Okay, he opened that up. Look at it. Okay, Uh, it could be could be ice. Oh I can see that. A little bit of stuff going past. It could be ice. Because they have had problems with the toilets which have frozen up. The toilet's frozen up, the exhaust vent for the liquid waste has frozen, and they've tried to unblock it. That might be what that is. That's the best guess I can give. But ice is a good game, well be it? Yeah, I think it's a good guess. And Sandy is so glad. He asked, we only just talked about the toilets the other day, all this innovation and new tech. And yes, they followed the hygiene facility or whatever it was. That's right, and it's given all kinds of problems. It's because of the the venting pipe has been freezing up, so they've turned a couple of times. They've turned the spacecraft towards the sun. It's also got heaters in it, which might be faulty or something like that. But I believe Victor Glover, who is one of the crew members. I think he's the plumbing expert. What a great job a job on. My plumber charges seventy five bucks an hour too. By the way, with one hundred and fifty dollars call out for you as well. That's right. That happened to me once I called a plumber and he said, oh, yeah, that's a council problem, and then build me forty bucks. That's true story. There you go, Sandy. It was the toilet. It was the toilet. Maybe thanks for the question. I love doing questions without notice. You just never know what's going to get thrown up, Bob, thank you, Fred, we're all done. Thank goodness for that. Maybe so maybe so. We'll talk again soon, Andrew, Thank we will. Professor Fred Watson, Astronomer at Large. And I don't forget to visit us online, especially our website where you can send us your questions text and audio. Spacenuts dot io is one of the URLs you can use or just do Space Nuts Podcast as a search in your favorite search engine and click on the AMA link at the top where you can send us text and audio questions. Don't forget to tell us who you are and where you're from. And thanks to here in the studio who actually was with us today, but he's had to leave because he had to go and see his accountant because apparently the tax department says there are confusion reactions that they want to discuss with him and from me Andrew uncle, thanks for your company. We'll see you on the next episode of Space Nuts. Bye bye. You'll be listening to the Space Nuts podcast. Available at Apple Podcasts, Spotify, iHeartRadio, or your favorite podcast player. You can also stream on demand at fides dot com. This has been another quality podcast production from nights dot com.