#462: Dark Matter Mysteries, Gravitons & Interferometry Insights

Hi there, it's Andrew Duncley from Space Nuts. Here we go again with a Q and A episode. I hope you're well. Thanks for joining us once again, and on this episode we are going to be answering questions about dark matter and dark energy. However, the twist on this is how do we predict movement in our solar system without accounting for dark energy and dark matter. That's a good question. Interferometry. Somebody wants to know if we can use space telescopes for that, and they're also asking about the life of Brian. We'll get into that shortly. Gravitons and whether or not they are responsible for gravitational waves and biblical floods. That's all coming up on a Q and A edition of Space Nuts fifteen. Second guidance is in Terannal ten nine ignition Space Nuts or three two nice as when I report it. Neil's good and joining us once again is his good self, Professor Fred what's an astronomer at large? Hello Fred, Hello. Andrew, good to see you. Good to see you too. And the voice is still struggling, so please forgive me. I might sound like what's like a famous news reader. If I keep that. Yes, I can bang it on at the moment, but hopefully it'll go away real soon. Shall we get started. We've got a lot to get through, So we've got a couple of text questions, a couple of audio questions. I think we'll just just plunge on in. Our first question comes from Trent Hello from Saint John's, Newfoundland, Canada. It's my understanding the existence of dark matter and dark energy first became necessary to explain why stars at the edges of galaxies are unable to escape the gravity of the galaxy. They live in. However, the existence of dark energy and dark matter is not necessary to accurately predict the relationships between the bodies and our own solar system. If dark energy and dark matter make up ninety six percent of the universe, why is it not necessary to predict the relationships between the planets, moons, et cetera in our solar system? Is its existence kept to a minimum within the bubble that is our solar system? Also, I have a question for Andrew. Is Hugh a real person? If so, what do you have him on some dime? I love the podcast, Please don't stop making it. Love you guys, Love you too. Trent I'll answer the second question first. Yes, Hugh is a real person. There, he is there. Look, can't just see him? Hang on, My name is Hugh. It is good to be a part of the show. No, he's real. He is real. He runs the whole company actually, and he's been with it since the very beginning. And yeah, he just sits there. And yes, look, we have asked him to come on the show and he declines, can't. Look. You know, he's an old radio man from way back. I actually met Hugh at a radio station in Newcastle when I was in high school and did job experience. This is a true story. I'd written him a letter asking him how to get in radio and he never answered me. And I confronted him on that when I was doing job experience and he said, oh, well, too bad, and. I thought, oh, very nice. Anyway, he ended up becoming my boss at the ABC, and here we are now working together on this podcast. I mean, it's a crazy world the way it all works out. I saved that story up because he didn't remember me, but I recognized him and finally put two and two together. The first time I saw him coming up the driveway at the radio station in Dubohre and I went, oh my gosh, I know. Who that is. And it all sort of unfolded from there. But I saved the story until the day I left the ABC and I emailed Hugh and said, guess. What and told him that story. Yeah. So yes, Israel Israel. Whether or not it'll ever come on the show remains to be seen, but put enough pressure on and you just never know your luck. Lovely bloke, and we really appreciate him, and I won't say anything nice about him ever again. Now, let's let's try and tackle Trent's question about dark energy dark matter and why it doesn't influence the movements of our planets within our solar system, given the fact that dark energy and dark matter makeup ninety six percent of the universe or thereabouts. Yeah, it's great questions, and it sort of comes about in terms of mutters of scale, if I put it that way. So, dark energy is something whose existence only becomes apparent when you're looking at things which are millions of light years away, and it's you know, it is. It is a Its effect is to cause the expansion of the universe to accelerate. Neither that expansion nor acceleration are prominent on scales that you know, are small enough to think about planets and stars or even galaxies actually, so you know, our galaxy is not being torn apart because the expansion of the universe, and that's because gravity is by far the most significant force over that kind of scale length. When it comes to dark matter, that's an interesting one and basically the Solar System is immersed in dark matter. It's a it's in a blob of dark matter, which is kind of the size of the galaxy, and so it is on scales relating to planets, it is perfectly uniform and so there it doesn't have any gravitational influence. We're sort of inside it, this uniform volume of dark matter. So the it's the even though it's you know, it's it outweighs normal matter when you look at the sum totals, when you when you look at the way objects in the Solar System behave, it's simply the gravitational pull of the the objects themselves that become important. That background, if I put it that way, of dark matter is irrelevant because it's completely uniform. So it's but there are interesting questions, and you know, the the existence of dark matter and dark energy is not just because we see galaxies that would tear themselves apart if they was nothing there other than what you can see. Galaxy clusters are the same, They would fly apart if all you could see was all that there is. It's not just those that tell us about the existence of dark matter. We've got gravitational lensing effects which come from dark matter, and we can look at the universe as at all. We were talking in the last episode about the angle Australian telescope and the way it's mapped the galaxies around it. The structure of material within those galaxies also tell you about dark energy and dark matter. In the science of cosmology. It's quite complicated stuff, but it actually reveals that both of them are real phenomena, and so it is still a mystery. It's still the biggest mystery that we confront I think in exploring the universe, with the exception of are we alone, it's an even bigger one. But yeah, dark matter and dark energy pretty good. Yeah, and a lot of work being done to try and unravel the mystery. But so far we yeah, we get more questions than answers. But yeah, one day we'll figure it out, hopefully sooner rather than later, but you just never know. We may never find out. Hopefully that won't be the case, but there's so much to learn. Thank you, Trent. Great question. As always, Our next question comes from Sunny Queensland. I think, hello, Fred and Andrew, it's blow here. I'm Welburn. Do you hold up the shortest. Name you listen? What is? I have a question for you. It's a keoretical one. I was wondering if it is theoretically possible to interferometry with the space telescopes and ground based telescopes. So we have the Hubble telescope, we have the Jam's web, and we'll have a number of large ground based telescopes. Can we actually do an intraferometry imaging of a star away object using these objects? Using these telescopes, That's how we got the center drop the black hole in Sagittarius a star, and I think we can do something similar with those two space telescopes and and then brought the ground based telescopes. I was wondering if that's to really be possible. Speaking of theories, has anybody done a study or between the correlation of the name Brian and astronomy. I'll give you four data points. There's Brian May, Brian Cox, Brian Schmidt and Brian Green. Surely they're not consequences anyway, looking forward to your response. Thanks Bo. There's also Brian from Sunny Queensland. Sorry, Bro, I don't know why I thought you were from Queensland. Maybe because I've got friends visiting from Queensland at the moment, queens and stuck in my head. But no, you're from Sunless Victoria. So yes, thanks for the Thanks for the question, Bo, what did he say? The shortest name in our in our listening audience. But you'd have to be careful because you know, admitting that your name is b oh, it's probably probably not the safest bed. In the world. He could get ridiculed for that one bow. But thanks very much for the question. Let's go with the Brian angle first, Fred, Brian's in astronomy. I love this. Yeah, this. Bunch for former Director of the Australian Astronomical Observatory, Brian Boyle. Now, yeah, you Zealand tall O'Brian. If you're listening, you don't think he does, but if he does, that's where he is. So but you could say the same for Fred, you know, because Fred Hoyle. Yeah, Fred. Fred Kepler, No, I moved that up. There are also got one. I've got one. I'll go one. Freddie Mercury. There you were, Freddie Mercury. Yeah. No, it's not far off, is it. Brian May and Freddie Mercury like that. They were. They were a lot of quite interesting. There are a lot of astronomers with Fred as their middle name, including David Marley, actually David Frederick Marlin. There were other Fredericks too, So I suspect there's not a link that you can make. I think a more interesting one is not to do with names. But I do remember many years ago when the old Siding Spring Lodge still existed, the one that burned down in the One Belong fire in twenty thirteen. We used to have evening dinners there for all the astronomers who were on the mountain because they were staying at the lodge. They used to have a. Dinner every evening, and conversations that those dinners were where many many collaborations were dreamed up, was quite extraordinary. So sometimes there were twenty astronomers around the table. I do remember one time sitting there and all of the all of the astronomers on one side of the table, everyone was eating soup. All of them on one side of the table were left handed. Yeah, And I thought, surely that was telling us something about astronomers and the way their brains are, because I've left hand too. So maybe all of all the threads were left handed, and all the bright right. Right could be it anyway, So curious collaboration, Sorry, curious correlationident I'm looking for Regarding interferometry. Let's come back to it for a minute. Even though we're talking about space. It's it. With current technology, it's not possible. And that is, you know, given that you can combine was it eight radio observatories to make the EHT the event Horizon Telescope, all facing one side of the Earth. They were all linked together by very accurate timing. The clocks were the vital part of that. And that's because in radio astronomy, the frequencies are low enough that you can actually you can interrogate the phase of the wave that's coming in. So a wave coming in has a phase, and that means you can concentrate on one particular or determine which part of the wave you're looking at a high bit or a low bit or whatever. Now you can do that in radio astronomy. The frequencies are low enough that you can actually analyze those phases as they're going through, and then you can mix them later in such a way that the phases actually add or subtract from the different telescopes that you're looking at around the world. But that's the whole, you know, that's the whole, not the rezon data. But it's very much the mode of operation of radio telescopes. They all operate, with the exception of single dishes. All the arrays operate on that principle of being able to know what phase your signal is at and then add or subtract at that instant the other ones to form an interferometer, which lets you measure very small angles and identify detail on very small scales. The reason why you can't do that with optical astronomy is simply that the frequencies are too high. There is no technology at the moment that can sample the frequencies of light waves in a way that will be reliable enough to add the signal coming from say the Hubble telescope or the Games web telescope. It may not be far away though, that we do have that technology, because I've seen papers on the use of what's called heterodyne methods, which are what they're used in radio astronomy, trying to apply those to optical seas, even though the frequencies are very high. It's very challenging, but it may one day be possible. It's not at the moment, but it's an interesting idea. And yeah, a nice suggestion book. Yes, indeed, thank you, BO, and good luck defending yourself from the bullies with the name B. This is Space Nuts Andrew Dunkley here with Professor Fred Watson. Let's take a quick break from the show so I can tell you a bit about our sponsor, Nord VPN, And just quickly, what is a VPN. It's a virtual private network that protects. You while you're online. It works on. Your PC, your notebook, your tablet, your mobile phone or cell phone, and even your smart TV. It's just a piece of software, but it's pretty powerful. Why do you need a good VPN? Pretty simple. It enables you to use the Internet no matter where you are, with total security by encrypting the data and maintaining your confidentiality. It's especially handy in places where you might be using public Wi Fi or unsecure public network systems and protect you from data breaches and scammers. But even at home, it adds a significant layer of protection and will warn you if you're visiting a questionable website or experience some kind of security issue. It's pretty cluey stuff. So which VPN do you need? The best one, of course, and that's nord vpn. Right now, they have extra discounts available for Black Friday plus up to four extra months for free, So just go to the special space Nuts url nord vpn dot com slash space nuts and click on get the deal to find out which package suits you. Don't forget all their other amazing services, including nord Pass, which is my fave. You can securely save all your usernames and passwords, and they backed themselves with a thirty day money back guarantee. The u r L again nord vpn dot com slash space Nuts. That's nord vpn dot com slash space nuts, and then click on get the deal for a Black Friday exclusive deal. As a space Nuts listener, That's nord vpn dot com slash space Nuts check out all the details in our show notes. Now back to the show. Space Nuts. Well, now our next question Fred, Sorry bo our next fresh question Fred. Comes from Vincent. Photons are the force carrying particle that mediates the electromagnetic force governing the behavior of things like magnetic fields. But they can also form into self propagating electromagnetic field, which we call light. If the hypothetical graviton were to exist, could it also form into analogous self propagating graviton waves? What would those be? I say graviton waves to distinguish them from what we know as gravity waves under relativity, since I think they would be two different things. Or are they one and the same? Vincent, mm, good question. It is a good question. I'm going to be I'm going to make a comment from pedants corner here, Andrew, because gravity waves are things that happen in atmospheres. Gravitational waves, however, are the wabbling of space and time that we can detect. And yes, I told it was from pedance corner. I'm sorry about that. Apologies, Vincent, you know what I mean. So that's an interesting question. And what we're talking about here is, you know that nexus between quantum theory and relativity, because relativity is what determines gravity as a waveform, the gravitational waves, whereas quantum mechanics would be what would determine the behavior of gravitons. I don't actually think, though, that there is any need to distinguish the speed of gravitons, which is the same as the speed of photons, light sym atomic electromagnetic particles. I don't think there's any need to distinguish that from the speed of gravitational waves, which we know is also the speed of light. I do understand, you know, the direction that Vincent's coming from in terms of separating these the analogue between that electromagnetic force and the gravitational force, and the analogue between photons and gravitoons. Sadly, we don't actually know whether gravisoons exist or that they likely who knows that they do, but we have no theory for it. But that's interesting thinking. I suspect the answeres know that they are one and the same, as you've suggested. Okay, yeah, it's just one of those mysteries that we are yet to resolve. The particle physics, i suppose, is probably one of the most mysterious areas of space science because we've been trying to you know, we've been trying to capture things, We've been trying to study things, the Higgs boson, for example, And yeah, they make these little discoveries, but then they come up with so many different questions as to why and how and what they actually discovered. It's a little bit weird, to say the very latest. The weirdest thing I read recently, which comes from a quantum physicist, is a paper that suggests and actually I think it was carried there was an interview with this gentleman carried by a new scientist magazine. But this person, who is at the one of the universities in Spain, he suggests that the laws of physics aren't really there. There's something to do with subjective consciousness, and that is a really spooky idea. And he's a quantum physicist. So yeah, but I'm afraid I think a lot of this code goes into philosophy as well, sort of metaphysics and things, and some of the terminology I'm afraid lost me go to Wikipedia to look up several of the words that I was reading, and I didn't understand what Wikipedia said either, So. It sort of seems to occasionally cross into the realm of we live in a world that's actually just been created by a mass consciousness rather than being a physical reality. Well, I think that's where this I think that's where this argument was heading. Yeah, because there are some that actually think that's a thing that we we've basically imagined ourselves into existence. That's that's why I think there's a book in that somewhere, but I'm not writing it. I could way too m So what was the answer to Vincent's question, Dono? It was maybe? Maybe? Probably, I mean basically I think it was. I think it's the one, the one in the same spade of gravital is going to be the speed of gravitation. Words. Yeah, very good. Thanks, excuse me, thanks Vincent, Okay, space nuts. Our final question, well, sort of a question the stiatementy weedy thing, which is coming from Christopher. Hello, gentlemen, my name is Christopher Blue, contacting you all again from Bayville, North Carolina, and I just want to tell if y'all had ever heard or read anything about the reasons there were floods. I think this was back in biblical times, but it was because the solar system had ejected a planet, and it had whizzed by Earth, leaving like a snakelike serpent of light across the sky. I didn't know if y'all had heard anything about that, or if I'm just having like a fever drink. But keep it up, guys, love the show, and hey, may it forth me with you? Thanks you, thank you, Christopher. And then I've got a terrible one line in response to Christopher, No way we're doing that, the boom tishmites. Indeed, hang on, I've got that sound effect. I think I think I've got that sound effect. I can't remember what it's called, though, it's got a weird name, but oh, hang on, is this it? There? It is? You can quick love it. What's it called. It's called rim shot. Oh yeah, well here's a riot. That's right. Yeah, that's right. Look, you can draw some events in history to astronomy, like the Christmas Star, which we've talked about in the past, and there wasn't anomally and as peronomic a normally around that time. That is well documented. So yeah, the question of whether or not these biblical floods that Christopher refers to could have been coincided with some sort of an astronomical event. Probably not that big a stretch, if you can get the timeline and the proofing. Yes, I think that's right. I think you've got to look at these with an open mind in regard to whether they're describing something that that happened. And there's a good chance. That there were. I draw the line at the Solar System ejecting a planet and a serpent like light across the sky. I think, though so, Christopher's question reminds me of a book written by two colleagues of mine, the Rod Observatory in Edinburgh. Suddenly, I don't actually have a copy of that book. I used to have one because they wrote a nice dedication in it, but I lent it to somebody. It was called The Cosmic Serpent, and that's what Christopher was saying is what reminded me of it. And it's by Victor Klub and William Napier to colleagues. In fact, Victor Club was my boss, and as far as I know, Victory is still going strong, living in retirement in by Year in northern France, in a castle where we visited him about a decade ago. Anyway, the Cosmic Serpent was the book that these two gentlemen wrote in the wake of their discovery that the Earth has probably been bombarded by comics and asteroids. This was all at the end of the nineteen seventies, and unfortunately somebody else kind of picked up the qudos for that discovery. They did write a paper which was published in Nature magazine in nineteen seventy nine, I think, called a Theory of Terrestrial Catastrophism, and it was all about things that may well have hit the Earth and how, you know, not just wiping out the dinosaurs, which was the new idea at that time, and it was that that caused the media star But there may have been episodes in historical times that have caused catastrophes of one sort or another that may have accounted for things like the flood to be ensconced in the certainly initially in the folklore, but eventually in the Pentateuke, the books of Moses. So it's it was. An interesting theory. I think things have probably moved on quite a lot since then. But these two were hard nosed scientists and they were prepared to look at a lot of the history of Earth in terms of how things like impacts from asteroids might have generated the kind of phenomena that we that we saw. So yeah, it's something that I think we as scientists need to be open minded about. And you know, it goes into other cultures as well as evidence that there was an impact, probably a large meteorite, which gave rise to some of the dream time stories of our first nations people. Here in Australia, certainly up in the Northern Territory, there are stories that tally with a potential impact about ten thousand years ago. You've got a culture here which goes back sixty thousand years so that culture is a living culture with a lot of verbal tradition in it and that's how you know the phenomena like a catastrophic event like a meteorite hitting the ground could be preserved in the stories that they have, the dream type stories. Fascinating. Yeah, it just reminded me. For this has got nothing to do with Christopher's question, but you were talking about ancient beliefs and ancient events and not to dismiss them. But while we were in Turkey the other day, we visited the ruins of Ephesus. I don't know if you've heard of the city of Ephesus, fascinating. Got the walk the original streets of Ephesus and saw the temple, and one of the things that I spotted there that was pointed out to us was the statuette of Artemis. They got us of, got us of the moon. Yepo relation to Apollo relation. He was, yeah, yeah, and so yeah, the statuette of Artemis is in Ephesus and still still exists there today. A Roman statue made around one hundred a d. I think, which still sits on a plints in in the city of Ephesus in Turkya. But you blink and you miss it, but it's there. Amongst all the ruins. But you can still see how the city existed and was laid out, and all the buildings. And one of the buildings that remains prominent and has still got quite a solid structure is the brothel, which is right near the road to the port. Because the ocean used to actually reach where Ephesis is no longer nearby because of the changes in earthquakes and things. But yeah, there was a road leading from the port into Ephesus, and one of the first buildings you come to is the brothel. So yes, but fascinating place, really interesting place. Has so many interesting ruins in Europe and in Asia and Turkey is no exception. Christopher, thanks for the question about biblical floods. Yeah, probably something somewhere has crossed paths with astronomy or space science that's created that possibility. Indeed, and thanks to everyone who's sending questions. Don't forget you can send in questions to All you have to do is jump on our website, Space Nuts podcast dot com or space Nuts dot io and go to the AMA link where you can send us text or audio questions. If you've got a device with a microphone, that's all you need to send us an audio question. We'd love to hear from you. Don't forget to tell us who you are and where you're from. Fred, thanks as always for answering everybody's questions. Much appreciated. I appreciate being here too. Thanks Andrew, take care and the hook Husky voice goes back to normal. Soon hopefully, Yes, and thanks to hear in the studio for not pestering us with questions. And from me Andrew Dunkley, thanks for joining us. Hope you can join us again on the very next episode of Space Nuts. Until then, Bye bye. I'm the man. By there you go, And when I find the when I find the intro, I'll hit it and I again say from me and Fred and you bye bye. You'll be listening to the Space Nuts podcast, available at Apple Podcasts, Spotify, iHeart Radio, or your favorite podcast player. You can also stream on demand at fights dot com. This has been another quality podcast production from the Nights dot Com