Dyson Spheres, Dark Matter Mysteries & Time Twists: #480 Q&A

Hi there, thanks for joining us. This is Space Nuts. My name is Andrew Dunkley. This is our final Fresh episode of the year, and I'll tell you what we're doing at the end of the episode over the Christmas New Year period. But it's a Q and A episode, which means we'll answer audience questions. We'll be basically focusing on Dyson spheres today. We'll be getting a question about the dark matter effect as a matter of fact, and black hole effects and time distortion without gravity and if you can chuck anything else, and we will time permitting on this Q and A edition of Space Nuts fifteen second the Channel ten nine ignition sign Space Nuts NI or three two. Space Nuts has. Been actually bought it. Bill's good And for. The last, last, last, last, last time official this year, we welcome Professor Fred What's an astronomer at Larchello. Fred? Hello, Andrew, good to see you again. You true really really been missing you. It's been so long. But yes, it is our final episode of the year and we've got all audio questions today and we'll try to answer one or two of them. But yeah, it's been a busy year. There's been a lot to talk about. Some amazing discoveries, some mysteries that continue to elude us, and that's what tends to spawn most of our questions. To be perfectly honest, are you ready to get into it? And we'll take question one? Why do we do that? Yes? Nothing else today? I think all the questions come from regular contributors. Our first one comes from mikey. Ethrid and Andrew Hope everything's well done there in the Southern Hammy. This is Mackey again from Illinois. If a dison sphere is a megastructure surround the star, how does the planet get light or is the planet inside of the dison sphere as well? And if the latter is the case, do you just prevent every other planet or that's already in that start from receiving any light, heat and energy, completely wiping out any other chances for life on any of those other planets and our moons orbiting it like you know, like Europa or tighten here, I mean without if I'm biggeno this right, If a dice and sphere in cases the sun, you know, how's how's life going to get a chance without any heat or sun or any type of energy from that star? Anyways? Just trying to wrap us all on my head. See what you guys think. Thanks, Thanks Mirky, you might get out of perspects, Mikey, that's really the solution, m I didn't know. It's a really good question. I haven't really thought about that side of it. If a civilization had enough technology to build a Dyson sphere and harness the energy of the Solar System's star, what happens to the light and what happens to the planets that reliant on that light and that energy that's been mopped up by an object that's basically surrounding the Sun. So that's the I guess the misapprehension that most of us have and what a Dyson sphere is because Dyson himself didn't envisage that his I haven't read the paper. Actually, it's published in Science back in nineteen sixty. It's called Search for Artificial Stellar Sources of Infrared Radiation. What he's saying is. That if you've got a structure built around a star because you've got such an energy hungry civilization, then you basically, you know, you build things around the star that collect the energy from the star and turn it into electricity. But they would naturally reradiate the excess heat in the infrared, and indeed he's suspecting that it would be perhaps the far infrared, longer wavelengths. So and his proposal was that that would be a far infra red signature around a star that you'd expect to be just pumping out visible light, wouldn't suggest that there was some sort of structure around it. Now, there is a quotation that I'm reading from Dyson himself who says a solid shell or ring surround a star is mechanically impossible. The form of biosphere which I envisaged consists of a loose collection or swarm of objects traveling on independent orbits around the star. And that's basically the bottom line that the dicesphere isn't really a solid sphere. It's a region around the star where you've got many objects in orbits, in independent orbits which are turning the energy of the star into electricity, so you're not harvesting all the light of the star. So Mikey's question is one that I hadn't really thought about before, but is almost directly answered by this, because you still have some of the radiation of the star that's leaking through coming between the swarming objects. It's not leaking, it's probably by far the bulk of that material. But you're adding to the light of the star this firing for a signature that tells you that there's object around the star that are artificial, and so you could probably put it wherever you want. I would guess the dysosphere around the Sun will be a swarm of objects, perhaps even inside the orbit of Mercury, and so there will be a slight reduction in the amount of energy going out to the rest of the Solar System. And it might be one of those things that would modify the climate of habitable planets like Earth. But it wouldn't shut down the light of the star altogether because you can't do that. It's mechanically impossible. It's dyce and so yeah, it certainly makes more sense when you explain it that way, and it's not dissimilar to what we're doing around the planet with communications satellites. I wonder if an alien species observing our planet from afar could detect that something's a little bit off because of all the satellites. Would that be possible? Do you think it would be? Well, this enough, you know, just straightforward radio radiation leaking from the Earth that will be detectable by certainly by a civilization having similar facilities to the square kilometer array which we have. The square kilmeter array claims that it will be able to detect an airport. Radar at fifty light years. So that's telling you that, you know, our airport radars will be detectable by as somebody at the other end having the same sort of equipment. Yeah, So it's so we're already we've already given away our presence in a cosmic sense. And I mean it's often quoted that the first high power radio broadcast that was made from Earth was the nineteen thirty six was it Munich Olympic Games that was broadcast around the world. And so there's a gentleman that wasn't really a gentleman, and that's saying a lot of things loudly and with force at that time in his speeches. His voice will be the. One that will go all around the local environment of the sun and make any alien. Not want to come here. I think, well, that was portrayed in the movie Contact with Jodie Foster, where the return signal from the alien species was images of the Nazis at the opening ceremony of the Olympic GA. Yeah, it was well used, very well used in that film. But in terms of a dison sphere around a star, yeah, not a solid object blocking light, but multiple objects collecting. What did you say on the infrared spectrum? And yeah, yeah, well really bilating it as far infra red. That's right, the collecting the visible light and re emitting it as far in for red. So it changes the spectrum signature of the star. And that's what Dyson's paper is about. All right, So nothing to worry about, Mikey, nothing to worry about. It's all good. Thanks, thanks for your question. Our next question comes from. Bill Hill, San Francisco Bay Area. I appreciate you guys answering my last question, which was can dark matter be thrown out of a galaxy and travel through space through some sort of gravitational event? So I'll give you an A plus plus and a cold star on that answer. Good job. And my next question has related if there was a glob of dark manner floating in space and I got too close to it in my spaceship with the dark matters gravity, pull me in and hold on. Jimmy and not let me go. So that's my question. Love the show. Thanks okay, thank you Bill. We'll be in San Francisco in a few months, Judy and know I. So we were going to once before, but we didn't. We regretted that, so we're going to go back. Yeah, the effect of dark matter. If you run, you're in your spaceship, in your yep, hit a glob of dark matter, or you're in its proximity. Are you stuck? I suspect not. No, I don't think you would be. Andrew. I think you're right. Because we've got We did some work on the Rave project, which I was involved with back in the early two thousands, which looked at the minimum size of a dark matter blob because we were measuring the velocities of stars, and if you've got blobs of dark matter, you would expect that to be revealed in anomalies in the velocities of stars. And we didn't see any anomalies. And I think that meant that you don't get dark matter blobs less. I'm trying to remember the number. I think it's about one hundred light years or thereabouts. Should go back and look through my stuff. But you're talking about very large lumps of stuff being the minimum quantity of dark matter, because we don't really know what it is. We don't know how it reacts with itself, but we believe that dark matter doesn't clump on those very small scales, and so you probably wouldn't notice it in your spaceship probably, you know the the It would be such a gradual change that your spacecraft would might deviate a tiny amount, but it certainly wouldn't be grabbed hold of so that you couldn't get away. So I think you said you wouldn't. You wouldn't have alarms going off, that's right. The claxons wouldn't be blaring or whatever it is they use on spaceships to tell you something strictfully. Wrong or something like that. Yes, yeah, so yeah, you probably wouldn't notice anything, Bill, You wouldn't even see it. It's just it's there. It's you know, we haven't even proven it, except we've proved it, we haven't found any is that right? No, I don't know. It's it's one of those mysteries we're still working on. We're looking for. Yeah, it's yes, there are many candidates for what it might be, but we haven't found any of them yet, so yeah, m hmmm, sort of telling about because of some sort that's the thing. Yes, that's it, that's what's the matter. All right, Thank you Bill. This is Space Nuts with Andrew Dunkley and Professor Fred. What'son space Nuts? Okay? Our next question, Fred comes from Sweden. Hi Fred and Andrew, O. You're from the west coast of Sweden. Here, I have yet another question about black holes. Is it true that space and time swhich rolls the moment you paused the event horizon? And if so, does that mean that space can go only in one direction, in one dimension towards the center, hence being the reason why nothing can get out? And does it also mean that time can go in any direction inside the event horizon? Thanks? Love the show. Thanks okay, lovely to hear from you west coast. Is there an east coast of Sweden for it? I need to look at a bed certainly is yeah? Okay, okay, it's mostly forgive my ignorance, but I've never been to that part of the world. Yeah, oh sorry, all right, So we'll be up there next month month after Lovely. All right, well, we'll be up around that way in July maybe July next year. I would think. I didn't you know, I've now forgotten this question. But it's about time and space in exchange on the advent horizon. And unfortunately I haven't had time to look at these questions in advance because I just had too. Much to do. And so that is one that I would need to follow up in. A bit more detail. I've heard the same thing, but I don't really know the physics of it. Just let me check something here, Andrew. I love it when we do this. I love it when we do this, just finding the answer on the fly. Well, it's good if we can. It doesn't always work. So here we are. There's a nice question on the physics stack exchange, which is our space and time interchangeable? Yeah? Yeah, And it's. Quite hard to quiet tired to tease out what's fact from what's fiction. It is all about Are there similar questions? I recognize that lovely as a metric for special relativity. There I often recognize equations and I quickly turned the page. Well that's one, yeah, I used to I used to put that in talks, that particular one when C squared DT squared plus d x square plus y square plus D squared equals d square. There you go. And that's basically it's a special relativity way of interchanging space and time. It tells you that the time is a dimension just like space. But that's not what OKI's question is, which is specifically about how it behaves in the vicinity of a black call. And I wouldn't need to follow up a little bit more detail on that. So apologies for the fact that that there's been so much going on in the last few days that I haven't got managed to get to that one. That's okay, we'll put it. We'll put a pin in that one, and we will get back to ORKI in the new year. We'll have a we'll have an episode in early janet mid January, I think where we can perhaps discuss that. So I'll put a yes. As you said, I'll put a pin next to it. All right, and I'm going to use a Stabilo foss highlighter and marketers homework. There we go, done, all right. We won't forget to walkie, and if we do, just send us a note and say, hey, bof DS, you forgot my question. We will get back to it. We've got one final question, which is not unrelated, actually, Fred in terms of topic, this one comes from one of our regular sender Inderies. Here is Buddy, Hello Space. Answer is Buddy from Morgan. Haven't we've been thinking about time distortion and gravity if in our space or we'll say there was no gravity but there was a time distortion. Okay, well, what do you think that would be? Like? Seems like to me like there would be some kind of drag from the slower end of things, floor on the time time moving things. And I'm wondering if you work that out, that drag could actually be gravity. All right, Thanks guys, love the podcast. Thank you Buddy. He's always got a bit of a curveball for us. Has Buddy, time distortion without gravity ultimately being gravity, I think was what the gubts of his question was. And yeah, look at that. Well let me let me start because that's exactly what Einstein's thinking was where he when he formulated the special general relativity theory. But you've got to remember that there is time distortion in special relativity, which has nothing to do with gravity. Special relativity is the theory that says, as things move as they get nearer, the faster nearer, the speed of light. All kinds of weird things happen, and time distortion time dilation is one of them. Your time system changes from the observed person to the person being observed. They've got different time systems, and that's just because of movement. It doesn't have gravity in it at all. So but he's right in that regard. But what Einstein then thought about was how that idea impacts on the gravity that we experience. He didn't. He basically didn't think of it as a drag. But his thinking was what we call well, he dreamed up something that we now call the equivalence principle, which says that gravity and acceleration are the same thing. So, I know, Buddy is right. A drag which you might think covers a deceleration is gravity. Gravity and acceleration are the same thing. And that's what allowed him to arrive at the general theory of relativity because it turns gravity into a geometrical phenomenon which we can understand. We've got the mathematics to understand geometry, and something called Remannian algebra Riemannian manifold is the is the mathematical shape of space as affected by gravity. It twists and turns as you put matter into it. And so general relativity is a geometrical theory and acceleration is part of that geometry. So yeah, So basically, buddy, that's what Einstein worked out, and that's what gravity is. Now you are, but we don't really understand it. I mean, what you're saying is it can be. It is identical to acceleration, and that equivalent principle, by the way, has been demonstrated with an accuracy of something like one part in in eighteen billion or something like that. It's a hugely accurate equivalence gravity and acceleration. We are told by Einstein that he imagined himself when he published the Special Theory of Relativity. He was trying to think how it would affect gravity, and he imagined himself jumping off a building and realized that he would be weightless as he fell. That you know, if he had coins or keys in his hand, that'd float out of his hand, his pipe had float out of his mouth, all of that sort of thing, And that was what led him to the to the equivalence principle. He called it the what did he call it? The happiest thought of his life? That gravity and acceleration of the same thing. Incredible. Yeah, at the sudden stop at the bottom that made the big difference there. That well, yeah, you don't want to go there too far. And you didn't do it. It didn't try out in reality. But it's what I always tell people. When you're on a trampoline, when your feet are not touching the mats, when you're in the air, you are as weightless as you are in space. You can hanceld out gravity because the acceleration is counceling out with gravity perfectly. Yeah, it's a fleeting moment of joy, that's all. That's fine. Thank you, buddy. Great question, and I love where your brain goes. I mean, you've got a very sharp mind, buddy. It's yeah, it's a delight to hear your questions. Okay, we'll take your. Space nuts. A question without notice, spread your moment of the year astronomically speaking, What do you reckon? What tickled your fancy? I'll give you time to think. But I just did a bit of a search on Google about the biggest astronomy stories of twenty twenty four. Artemus two is up there. The discovery of ultra massive galaxies there was a story about a white dwarf, and major events like the total solar eclipse in April and a few other things that popped up during the year. Those were probably the stories that got the most headlines. That doesn't necessarily make them the biggest stories of the year, they were probably the most published from what I've gleaned. Anything stand out. For you, Well, yeah, several things actually. On the I mean, yes, the eclipse was fantastic on the was it the I can't remember. It was in April sixth I. Think fourth fourth four let me check the from the eighth was. The eighth of April, so that was that was fantastic. But you know, eclipses every year or so, so you can see a good eclipse. This particular particular one was particularly good. It was a four minute eclipse, which is long. But a couple of months before that, the one in twenty year event was the auroral display on the twentieth of May. Was no ten to May. Ten to May a twenty four year event. And I saw the one twenty years ago because I could see that from the center of Edinburgh, but unfortunately the one this year I didn't see because, like you, we were under cloud for weeks out of time. The discovery of the year though, I think it could be something we talked about in the last episode, the fact that it's beginning to look as though dark energy is not constant. That could be a Nobel Prize winning discovery eventually. So yes, that's a big, big news story. Yeah, it's huge. It is a huge story, all right. Fred. That brings us to the end of the year. I'll just tell people what we're doing over the next few weeks. While we're away. We'll be digging up stories from the archives. Yes, we've been around long enough to have archives, so we'll be talking about the first James Web images, the first image of Sagittaris a star, those moon samples that they took fifty years to open, Remember that story, exoplanets, that rain gems. There's a story in there about dark energy, surprisingly enough, and NASA with its big warning about the rising sea levels and the effect the Moon will have in conjunction with that on tides. That was a massive story which we did well more than three years ago, but it still applies. So those stories, plus some updated news coming from one of our colleagues on the end of episodes over the Christmas New Year period, and we'll be getting back together mid January with fresh episodes and that little bit of homework for Orcie. In the meantime before we finish, I've got to say some thank you. First of all, thank you to you, Fred. You are amazing. We love you dearly, and it is such and honor to have you on Space Nuts and have been doing it for so long and you know, it's just terrific and people really appreciate it, especially me and Hugh. Thank you. Andrew likewise, your efforts and huge efforts behind the scenes. Often go and see. That he doesn't do anything. I know that, but you don't go there. But you are the consummate professional when it comes to interviews and broadcasting and it's a pleasure to work with you as always. Thanks Fred, And I know it's by the time this episode goes, you'll have already had your birthday, but many many happy returns for your birthday, which was sometime in December ish. Yeah. I would also like to say thank you to our audience because without you we'd be nothing, and you are one of the most dedicated audiences I've ever had the experience to work with or for and we really do appreciate and all your support, our patrons, we love you. Thank you for putting money in the kiddie. You don't have to do that. We've never asked for it, but you've done it anyway. All four or five hundred of you incredible. And our sponsors, of course, we love them because they keep Hughes Maserati going, which is that's what it's all about, yea, And from me, it has been a great pleasure this year looking forward to your company in twenty twenty five. Can you believe we've rich that year? Good? Great quarturally. Yeah, it's unbelievable, it is, it is. Thanks Fred, farewell. We'll have a great Christmas New Year. I know this is probably going to go to air after that, but whatever, and we will. No, I don't know, no, just before. It'll be just next week, next week Christmas. I had it all on a calendar. I've lost the calendar, but yeah, that proves I need a holiday. Take care, Fred, and love to Marni and everybody, and we'll see you soon. Sounds great, Andrew send to you. Thanks very much, Professor Fred Watson, Astronomer at Large, and thanks to Hu in the studio. For his tireless and invisible work getting this together, because he really does work very, very hard, and that is no joke. And from me Andrew Dunkley, thank you again for bearing with us for another year and we'll see you in twenty twenty twenty five, Take care, Merry Christmas, Happy New Year, and by for now 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 bides dot com. This has been another quality podcast production from nights dot com