Gravitational Wave Wonders, Lunar Orbits & Satellite Showdowns: #476 Q&A

Hi there, Thanks for joining us on a Q and a edition of Space Nuts. Andrew Dunpley here. Hope you're well. I hope you can stick around a while because we've got questions from all over the world and they will be focusing on gravitational waves, an interesting question about how they behave or do they behave in certain ways. We're going to talk orbiting space stations and super constellations, which is certainly an issue around the planet at the moment. An observation, I suppose with a question as the kicker about dark energy and ultra mass black holes and noncompatible spacesuits has been brought up again. We'll talk about all of that on this edition of Space Nuts. Fifteen second to the Channel ten nine ignition Space Nuts or three two. Space Nuts. As when I report it, Mel Good, he's back. I don't know why he keeps coming back, but he's back again. It's Professor Fred. What's an hello? Fred? I'm only back because I can't actually get out of this room. I'm just locked in here all the time. So yeah, I mean, I tell you you're never left. No, it's the Tardis effect. Shall we get straight into it and answer some questions. I think we should yes, or at least pretend to. Okay, this first question comes from Colin. I'm not sure where Colin is, but he asks, is there any evidence that gravitational waves reflect and or refract like pressure or light waves. I know we've talked about gravitational waves a lot, but I don't know if we've really analyzed this particular aspect of their behavior, if it exists at all. We haven't. And it's a good question because we you know, we know that lightweight which are transverse waves, so like things are vibrating kind of horizontally or vertically, they are refracted and reflected. And sound waves are too, which are pressure waves. They are longitudinal waves changes in pressure. Now, gravitational waves are neither of those things. They are quadruple waves, which means that space is sort of distorting in a peculiar way when they travel through. But here's the crunch, Andrew, And there's Jordy agreeing with me, which probably means that on his back. So you'll go berserk in a minute. But that's all right. Here's the crunch. How do you so think about refraction? This is the bending of light when light passes into for example, a piece of glass. Why does light refract in a piece of glass? Why does its angle change? And it's because the speed of light in a piece of glass is lower than it is in free air or a vacuum, and so the light waves are slowed down when they pass into the glass, and that produces the bending phenomena refraction. Now, gravitational waves are not like that. They always travel at the speed of light, so they're not refracted in the same way that we would imagine light being refracted. That phenomenon doesn't exist for gravitational waves. What does exist, though, is we know that space time is distorted by matter that comes from Einstein's general theory of relativity, and space time is distorted, but light wants to follow the distortion. In other words, the light doesn't know that it's going through distorted space time, and so it just follows the distortion. And that's why we see gravitational lenses. Because the space time around at cluster of galaxies is distorted. The light just goes on its merry way at the same speed, and it's not refraction. It's gravitational lensing. It's bending by gravity, and gravitational waves behave in the same way. So they do bend, but it's not through refraction, it's through gravitational distortion of space. Work that one, now, so that means gravitational waves just keep going. They're going what they think is a straight line, but the straight line isn't straight because it's because the space is distorted by it. They're called geodesics. It's it's basically how so that's the way we believe orbits work in in relativity. You know, if you've got a planet that's got something in orbit around it, the planet produces a well of gravity. You can think of it as a trampoline distorted, and an object basically thinks it's going in a straight line through that distorted space, but actually it's going around in a circle in an orbit. That's sort of and the same thing kind of happens to both light waves and gravitational waves. They think they're going along the straight line, but they're not because the straight line is bent by gravitational pool. I'm not explaining this very well. I can see that. I can see by the expression on your face that you think it's lost it altogether. I have no idea what it's still about. What kind of bent my mind out of shape. Is I expected you to say the opposite. I expect you to say, now, gravitational waves. There are power under themselves, and they will do what they like and nothing will stop them from hitting a straight line. But that's not true. Although they think, yeah, well it is. They behave as though they're following a straight line, but that straight line is distorted by the gravitational pull of something else, you know, like a cluster of galaxies. Yeah, so they are affected. They are affected, yes, but it's not quite the same as reflection or refraction as Colins proposed. Interesting, very interesting. It's a great question, Colin, and thank you for that. Yeah, absolute ripper. All right, thanks Colin. Our next question comes from Michael Whiting in Chroma in the UK. Hi, Andrew and Fred long term listener, and would like to say thank you for a brilliant podcast which I look forward to every week. Thank you. Thinking about the future, going back to the Moon, et cetera, is it possible to have a space station orbiting both Earth and the Moon in say technical terms a figure eight. I'm assuming it is possible, but radiation shielding is more the issue. This would surely make it easier to transit for Moon. That's his first question. When we deal with that one, I'll ask the second question. So I like this idea if it's feasible. Well, it is absolutely And that's actually if you've got to look back to nineteen sixty eight and look at the trajectory of Apollo eight exactly what it did. It followed a figure eight orbit around the Earth and the Moon, and that you could set up a stable for a bit like that, But it doesn't really make for an easier transit for Moon missions. Because if you've got something that's in a figure eight of a figure of eight orbit's going from Earth to going between the Earth and the Moon. When you you know, I suppose you imagine that's the kind of space station you want to jump on board it. To jump on board, you've got to have a spacecraft that is following exactly that orbit. Yeah, you've gotta loannch it and get it into that orbit in order for you to make the rendezvous between the two. Now, yes, maybe if you have a something like the Gateway that the Gateway satellite which is being proposed as part of the Artemis program, in orbit around the Moon, then that's like a space station which has lots and lots of facilities on board, which are a little transit shuttle might not have a transit shuttle, might look more like a crew dragon spacecraft or you know what are they called? I can never remember its name, the bullying what are you? Star liners? What that was the name I thought of, and I was thinking, No, it's not a star lineer that's an aircraft. No, but it is. It is. It's a star liner, yeah, the star liner. So you know, they're very modest pieces of equipment. They can hold up to seven people, but there will be a crowded, crowded house. So I guess you could do that if you've got this sort of gateway like space station that is constantly in a figure of eight orbit, and you zoom your passengers up to it, hop on and it acts like a boss, then you've got to hop off at the other end before it brings you back to Earth. I'm not sure that it would make life easier. I think it might make life a bit more complicated. But it could be done, Yes, it could be done. Yeah, all right, so you're thinking, is right, Michael, But operationally might prove too much of a headache. Michael's got another question. With China adding a new currently visible satellite constellation, our discussions being had to decrease the visibility of the satellites as was achieved with space x Starlink constellations. Follow up question to that, does China, Thanks Mike, and this. This question goes right to the heart of stuff. I talk about a lot, and you know part of my role. There's the astronomer on the loose. The answer is yes, kean Fan I think is the name of the satellite? Am I have that long? Because it's a few days since I looked at it. It means a thousand sales. That's the name of it. And there fifteen thousand satellites I think have been filed for in this constellation. All the evidence I think last time I looked there were about forty in orbit. Now with mounting evidence that they are pretty bright. Then as use exactly as as Michael says, SpaceX did a lot of work to reduce the visible light profile of the Stylink satellites. We don't think that's happened with Kian Fan, and we don't really have any avenues into the company that is running them in China. Now my hope is that this will change because we now have satellite constellation interference to dark and quiet skies. That is now an agender item on the Committee on the Peaceful Uses of Outer Space, the UN Committee on the Peaceful Use is of outer Space. They have a Science and Technical subcommittee and it's now an agender item on that committee, so that raises its profile. China is a player in this forum. They come to the party with the kopuas that committee. So my hope is that there will be avenues for improvement with that, But at the moment we don't know. Yeah, that's a pity. I mean, they have a vested interest in space exploration and understanding as much as anybody else, so I suspect that it would be in their best interest and they would benefit from insulating their satellites, so to speak, to reduce the impact on observational and radio astronomy from the ground. That's right. In fact, that's exactly the comment. I was in a meeting a few months ago now and I made exactly that comment that China has a very large cohort of astronomers who are themselves using well amongst the biggest single dish radio telescope in the world, the fast telescope five hundred meter radio dish, and they also have optical telescopes, so they would have a voice within China and hopefully the space industry in China will listen to them. So so my you know, I'm an eternal optimist Andrew, as you know. But the answer to Mike's last question does China listen? Is we hope they will. Yeah. Yeah, fair point and really great question to ask. Probably it's a scary question to ask because you just you don't know what China they get. They get offended at things out of the blue, and you know, and they stopped buying our wine and thanks it. Was twenty billion dollars worth of of trade exactly. Yeah. Anyway, great questions, Mike, Thanks for sending them in. This is Space Nuts Andrew Uncley with Professor Fred what's a Space Nuts. Yep, it's a Q and A edition where we answer audience questions. And we've got an audio question now from one of our regular sender in errors. It's Rusty for donny. Brook and Andrew, it's Rusty in donny Brook. When the Dark Energy said you really suck? What did the ultramassive black holes, say in response, nothing, it was to taken aback to get a word out. Now, if black hole truly generate dark energy, it's got to be a local phenomenon because our study of gravitational waves have shown us that space time distorts at speed of light. The effect would be too small to be able to measure it in stellar mass black holes, but as we get bigger the effect would be too clutted in super massive black holes in galaxies too, so that leaves ultra massive black holes in the center of large. Which, if there are any. The hair Wooden astronomer specializing in multiple objects spectrometry Fred make observations to gain support for the existence of such ultramatic black holes and the granular nature of dark energy. So this would replace the notion that large scale structure of the. Universe was caused by tonic oscillations in the early universe. Two. So thanks space nuts, have a good and. Thanks Rusty. I'm always worried about Rusty because he just tries to throw your curveball occasionally, Fred, And I don't know if he's just tried again. Yeah, I mean, the lovely thing about Rusty is that in three minutes. He rewrites all the textbooks. It throws away. The big bank throws away. Dark energes don't throw away. They do bag. But I see where he's the point he's making because we've covered this idea before that dark the ultimate source of dark energy might be black holes. That's some research that I think was done earlier this year, and so Rusty's conclusion from that is that dark energy must be clumpy, which I think is a reasonable conclusion. But I don't know that that is the conclusion that's drawn by the people who are the proponent of this theory. I need to go and have and I look back at the theory of black holes being the source of dark energy. But if there were, so, look, I'll rise to the challenge as a multi object spectroscopist, which I'm not really anymore, but I was, I wouldn't that this would not be the technique, the technique that you'd use though to detect them. So what what Rusty's proposing is that there are these things ultramassive black holes, which I guess we might say are more than one hundred billion times the massive the sun. They will there monsters, absolute monsters, and they're lurking around in the voids between galaxies. Now, those voids are part of the sort of honeycomb structure of the universe that we think was imprinted in the Big Bang. That the work that people do on the physics of the Big Bang event tell you that there will be these strings of dark matter which would collect hydrogen gas, which would form stars and galaxies and so. But those strings and sheets of dark matter make essentially what looks like a foam or a honeycomb pattern when you look on very large scales. So in the middle of that, there are very few galaxies. So if you put. An ultra massive black hole in the middle of that, what would you see? And the answer is you would expect to see when you looked in that direction, because you'll be able to see the galaxies on the far side of that void, a sheet of galaxies. You would expect their images to be distorted in the way that we are familiar with gravitational lensing by a massive massive object. And so I don't believe that such distortions have been found. In other words, you know what you might see is is nothing, because there's a black hole that sorry, you'd see no evidence of something in the in. The in the. Intermediate distance, but in the far distance you'll be able to see galaxies and clusters of galaxies whose light would be distorted by the black hole that you couldn't see in the foreground, if you see what I'm saying. So I think we have evidence already of such ultra massive black holes. Okay, So avoid with a black hole would give you a vision of distorted galaxies and it's behind it, whereas a void without a black hole, you just wouldn't see anything. You'd see the galaxies, but they wouldn't look any from what they normally look. Yeah right, you know you can we know from particularly from the new web images, just how distorted the shapes of galaxies are when when they're seen through a gravitational lens caused by a cluster of galaxies in the foreground. So yeah, it's an interesting question though, as Rusty is always always are Yeah, yeah, he's always thinking. That's the thing, and that's that's what it's all about, to provoke thought and come up with ideas and try to try to challenge those in the in the astronomical seats of power, such as your good self read yeah, always always throwing out the challenge, Thank you, Rusty pace Nuts. And our final question reflects on an issue we spoke about but fairly recently. This comes from Mark. Hi. It's Mark in London and Canada. I was wondering you were talking recently about the astronauts being stranded and the Boeing spacesuit being incompatible with the SpaceX vehicle. I was wondering, what does that mean? Why can't they just wear their suit? What does the soup plug into the vehicle or what's the incompatibility? Appreciate an explanation of that, Thanks, guys, and I figure hughes but in that studio for the best part of the decade. So it's time to free who when just started a campaign to let them go on? Thanks, start a petition, Mark, because I'm not going to help him. Gosh, people are starting to sympathize with Hugh and starting to worry me a lot. I'm sounding really evil now you are. Yeah, you know, look, God, I think I think he deserves a break. Really, he's got us to put up with for a start. Yeah, well that's true, that's very true. Mark asks about space suit compatibility. Now we go back to that situation where there were I think, with three astronauts on the International Space Station who couldn't get back on the Boeing star Liner because of a fault, so it was sent back empty and they were to be returned on a space X. Rocket. Yeah if you like. But their suits, the Boeing suits didn't work in the space X vehicle, and there was talk about sending them back in their underpants or something because they just, you know, their suits were useless an emergency. Yeah, that's right, it would two do astronauts, not three as well. It's sort of Tony Williams and Butch will Moore. That's right. Yeah, and they're coming back. Are they still there? Yeah, they don't have it. That still February, that's right. Yeah, that's right. Yeah, they're the bowing star Liners back. All good and well, but they're still up there. Mark's question is a good one. Why can't they just wear their suits? What's the problem. So what's happened is that when the SpaceX it's not a rescue vehicle because it was already scheduled, but when that SpaceX craft went up to rendezvous of the ISS, which was last month, was it or earlier this month? I can't remember. I think it's last month. It took SpaceX suits up with it. It had a crew of only two rather than four, and two empty suits for Butcher Williams, sorry Butcher Willmore and Sunny Williams to come back with, why do they need that? Well, the star Liner and the SpaceX Dragon Capsule are completely different. They were developed independently, and in many ways, NASA wanted two different ways of transporting their astronauts up and down to the space station because it gives them a choice, that's the thing. And it turns out that it's just as well that they did, because these you know, SpaceX has had far fewer problems than than Boeing have. If we've been waiting for Boeing, we would still be waiting, whereas Crew Dragon has been flying I think since twenty twenty or thereabouts, quite a while ago, maybe twenty twenty two. Anyway, they're different spacecraft. They've got different you know, umbilical fittings, they have different restraint fittings, an entirely different appearance. The way to check this out, mark is to have a look at the USA Today website, and there is a story on that which is entitled you Can't use line of spacesuits in a SpaceX capsule. These images show why, and it becomes very obvious because all the plumbing is different. The spacesuits are themselves quite different. They've got different helmets, different fittings, different boots, different gloves. Everything's different, and they're not compassible. That's the bottom line. But it's a very nice article. Actually, it's got some lovely diagrams and illustrations showing the differences there. USA Today dot com is the place to help for that. I I just found it and I'm just having a quick squeeze through it, and yeah, you're right, there's some great diagrams and information in there. And now, just to clarify it a bit more, I assume when you come back to Earth you can technically do it without a spacesuit. So it's not like you have to have the suit on so that you can breathe or anything like that. No, that's right. It's it's basically a precaution. You know, if the if on re entry the spacecraft sprang a leak, for example, and started depressurizing, if you didn't have your spacesuit on, you'll be in big trouble. But that's an unlikely event. They I don't think it's ever happened before, so it's. It's it's. They could have done it exactly as you've said, had there been an emergency, those astronauts Sonny Williams and Butch Wilmore could have come back in a crew Dragon flight. I think they were rigging up sort of emergency seats in one of the crew Dragon craft just in case this needed to happen. But yeah, they wouldn't have had had a spacesuit, so's it would not have been possible for them to wear spaces on their way back. But that will not now be the case. That's fixed because there are now two extra SpaceX spacesuits on the Internet Space Station for them to come back when they returning February. And I do like you know that that article that I just mentioned, the one you've just found, it's got a really nice diagram of what we mean by redundancy. You know, redundancies to build in safety precautions. And you can either do similar redundancy or dissimilar redundancy. And it's dissimilar redundancy that we're talking about here. Two independently designed systems performing the same task in two different ways. It sounds like VHS and beta maybe so, yes, that's right. Yeah, it reminds me of race car drivers. I mean you could, you could drive a race car in your underpants, but it's much safer to way the fiery hard ensued. That's correct, of course, and a helmet absolutely. Yeah, all right, Mark, thank you very much. Great to hear from you. Thanks for all the questions. And if you have questions for us, please send them through via our website. Just go to spacenuts podcast dot com or space nuts dot io then click that little thing at the top that says ama and you can just fill in the blanks with the ask me Anything option in the form of a text question, or you can just hit the start recording button then send us an audio question. Don't forget to tell us who you are and where you're from. And while you're listening to us online, please leave a review on your podcasting platform. Reviews very helpful. They get us noticed by more potential listeners, and that's what it's all about. Thank you, Fred. We're done and dusted. Good job sounds great, Thanks Andrew, and we'll talk again too. We will, indeed, and am I going to release who from the studio today. Nope, I am not, and I've kept him on mute for the entire episode. And from me Andrew Dunkley, thanks for your company. We'll catch you on the next episode of Space Nuts. Bye bye. You'll be listening to the Space That's podcast. Available at Apple Podcasts, Spotify, iHeartRadio, or your favorite podcast player. You can also stream on demand at bites dot com. This has been another quality podcast production from Sites dot com.