#407: Unraveling the Universe's Expansion Enigma & Mars' Hidden Volcano

Hi there, Thanks for joining us so on yet another episode of Space Nuts. My name is Andrew Dunkley, your host, and it's good to have your company again. Thanks for joining us. Coming up, we'll be looking at an old chestnut, the expansion speed of the universe. The theory is again under the spotlight due to for a change, non conflicting evidence, so we'll talk about that. And a giant volcano has been discovered and it was hiding in plain sight. Guess where. Yeah, you're right, we'll you're talking about that on this episode of Space Nuts. Fifteen second guidance in Channel ten nine ignition sequence Space Nuts four three two Space Nuts as when I report it, Bill's good and joining us to explore all of that is Professor Fratt Watson, Astronomer at Large. Hello, Andrew, Good to see your smiling face again. You look a bit healthier than you did last time I saw you. Yeah, yeah, improving. I generally don't suffer jet lag for very long, but this time it's really hit me hard. And I think it's got everything to do with the fact that I managed to sleep on the flight home, which was bad because we got home at eight o'clock in the evening, so and I calculate I probably slept seven hours on the plane because it left in the evening and good, yeah, yeah, I know. And then when we got back, of course I didn't really feel that sleepy. So and it's taken me a long time to adjust, but I'm starting to get it all back, which is good. And yeah, getting over the illness that came with it. I do not recommend having a heavy cold or COVID or whatever it is I had in conjunction with jet lag. They do not like each other and they fight with a nail. So yeah, not a fun combination, but I'm sure it's not uncommon in this day and age. But yeah, we're getting we're getting through. Its been a bit of a long haul. Boom boom, How are you how? Things fine? Thanks? Bit chaotic due to my upcoming trip as well, So we'll be we'll be fine. We'll be fine. Yeah, we can't wait to talk to you about that. In fact, when this episode is out, it's probably around the same time as you'll be at the event that you're attending, So that'll be good. Fred. Let's get stuck into it. We've got a couple of really amazing topics to talk about things we've talked about, well, one of which we've talked about many times before. The other we haven't because it's only just been discovered. We'll get to that shortly, but let's talk about this situation with the expansion speed of the universe. We get a lot of questions from the audience about it. It's in the news again because an old theory has sort of been confirmed by more evidence from a new source. And and that's I mean, that's great, but it's also got people saying, well, hang on a minute, this can't work. It doesn't doesn't add up. There's still a hole in the information and we can't figure it out. It's it's really quite an intriguing scenario and the real head scratcher. And there's a lot of scratch scratched heads in the astronomical community, exactly as you've suggested that, Andrew. So what what are we talking about. Let's, as they say on the radio, let's unpick the story a bit. We we have a number of different ways of measuring the expansion of the universe, and what we're talking about here, Andrew, is the expansion of the universe now. In other words, we're not talking about, you know, back in the day or back in the origins of the universe. We're talking about the expansion speed now, and astronomers have got a slightly curious way of expressing that it is because the bottom line is, with an expanding universe, the further away you look, the faster something is receding from you, and that is just standard geometry. The further away you look, the faster it's moving. That was Hubble's discovery back in nineteen twenty nine. And the speed is that things are moving away from us are measured in units of kilometers per second. That's the speed. We can understand that, but it's kilometers per second per megaparsec. In other words, well, let me just tell you what a megaparsec is. It's a million parsex. One parsec is three point twenty six light years, so a megaparsic megaparsec is three point twenty six million light years. To use the numbers that we're more common more commonly familiar with, astronomers use parsex and megaparsex because that's the measurable quantity. You can't measure light year, but we can turn the measured quantity very easily into a light year, which actually is a nicer way of expressing things. It's one most people can get their heads around. The distance light travels in one year. So the value that the Hubble telescope arrived at. And remember when the Hubble telescope was launched back in nineteen ninety, one of its main aims, the main aim of the mission was to measure the expansion velocity of the universe, in other words, measure the Hubble constant. And that was because at that time, and I remember this very clearly, there was huge disparity in different camps on what this constant was, ranging from fifty kilometers per second to megaparsec per megaparseic to one hundred kilometers per second per megaparsic. In other words, they differed by a factor of two. Two groups of astronomers who were both convinced they were right, but their values were so far apart they could never be reconciled. And it turned out when the Hubble Telescope did its work and measured that expansion, the value was almost exactly the average of those two fifteen one hundred it's seventy three kilometers per second per megaparsec, and that is now the accepted value coming from the Hubble space telescope. However, the problem is that there are other ways of measuring the Hubble constant, and they involve looking back at the cosmic microwave background radiation, which is, as you know, we've talked about it many times before. It means we're looking so far in space that we're looking so far back in time that we're seeing back to a time when the universe was still luminous. We're seeing effectively the last vestiges of the flash of the Big Bang, and in fact we're looking back to within about three hundred and eighty thousand years of the d bank. Now, that cosmic microwave background radiation I call it the cosmic wallpaper because it's behind everything else that we see in the universe, but also because it's got patterns on it, like old fashioned wallpaper often did. And those patterns are caused by actually acoustic oscillations within the fireball of the universe, so slightly warmer and slightly cooler zones on that cosmic microwave background radiation, and by studying those you can arrive at a value of the Hubble constant. The problem is it doesn't agree with the Hobble. The method that the Hubble telescope used, which is to look at I didn't say, this is to look at a particular type of variable star SEFID variable stars which have a known brightness. They are what we call standard candles. So that gives you the Hubble telescope observations gives you seventy three kilometers per second permega passec, but looking at the cosmic microwave background radiation you get sixty seven kilometers per second per mega passec, which is it's sort of, you know, almost a ten percent difference, not quite but getting on that way. So that is what we call the Hubble tension. That is what whearies people that we are getting a different answer. And in a way, you know, back in nineteen ninety when the Hubble telescope was launched, people would have just ignored that difference because they would have said, well, you know, that's near enough for us to know what's going on. But today we're in an era which my PhD supervisor, Professor markham Longer was described as an era of precision cosmology. We are in an era of precision cosmology in other words, we can measure these parameters much more accurately than we ever could before. And so this difference from the cosmic microwave background radiation sixty seven kilometers per second megapassek to the Hubble telescopes seventy three kilometers per second per megaparsec. That is a problem and it's something that we would like to understand and we don't. So that's the backstory. Now, enter the James Waiting Space Telescope JWST, which I'm sure many people were hoping would absolutely solve this problem and say, Okay, this is exactly what's happening. And that didn't happen. No, it didn't. What the James Webs based telescope has done is confirm the Hubble telescope value. They've looked at the same sort of the same stars. They've looked with a much bigger telescope than the Hubble, penetrated much further into space because it's got a bigger mirror, and what they get is the same answer. And by the way, this is research led by Adam Reese of Johns Hopkins University. He was one of the three people who got the Nobel Prize for the discovery of the expansion, the accelerated expansion of the universe. So he's not somebody you know that you can ignore. Is research is top rank research done on a top ranked telescope, and it basically gives the same answer, in fact, not basically, it gives exactly the same answer seventy three kilometers per second omegaparsec as the Hubble telescope did. And what they're doing is they're using a a combination of these sephid variable stars and another distance indicator, which we call type one a supernova. These are exploding stars that always wind up with the same maximum brightness. So you you could describe these types of stars as standard candles because they are luminous and they have a standard brightness. And you can describe the work done on the cosmic microwave background radiation as being the standard rulers, because you're measuring the separation of hot and cold spots on the cosmic microwave background radiation glow itself and standard So we describe those as standard rulers because they are telling we kind of know what those separations ought to be, and we can measure how they look. Somebody has suggested the possibility of a technique called standard signs, and I haven't come across that term before, but I like it very much. Where you can use gravitational waves, so using gravitational waves, and I guess the standard sirens is because they effectively the same frequency ranges as audio waves. Standard sirens from gravitational waves might one day help to resolve this problem. But at the moment, we simply don't have accurate enough values. The error bars are too big, so we don't have accurate enough values to use the standard siren method to resolve the issue. But that might be the way it goes. At the moment, Hubble tension remains with us, and we don't know what the expansion rate of the universe is. Well, you know, we know two numbers. We know two numbers, but we don't know which one's right. Yeah, So James Webb confirming the data from Hubble does not absolutely guarantee that that number is right. The other number is sixty seven kilometers per mega PARSEK, which was based on the barrier acoustic oscillation theory or evidence. The difference is six, which is a big number in an era, as you said, where accuracy is becoming the norm you, I can throw you on the spot here, Fred, do you have any theories about what the difference might be why exists? I mean, it's the big It's probably a dumb question to ask because no one knows the answer. No, But what I mean, one possible answer is really intriguing that you know, there are phenomena play that we don't yet understand or know about new physics. The universe might not be as we think it is. We've got this very neat and tidy view of the universe, and that's a fairly ambitious thing when you think that about a whole universe. We might have neglected something that we have not yet discovered. You know, certainly our basic theories are all correct. Relativity works perfectly, quantum theory works perfectly, and themselves are not reconcileable. So that's another tension as well. But the hubble tension may come down to something that we just have not discovered yet, and when we do, it might change our view of the universe markedly. New physics, if I can put it that way, Physics that we don't yet understand could open the door to all kinds of different things, extra dimensions, all sorts of things of that sort. So it's very exciting in its own way, this hubble tension. People are going to keep chipping away at it until we get an answer, and somebody will come along with a theory that says, ah, what if there was a fifth dimension and it did this to the other four? Ye, that could be the answer, but we don't know yet. Look, let me throw a curveball at you, just because it is a curveball. But if we do find some new piece of information that answers the question, could that then put a dint in Einstein's theory of relativity because he's always thought he was wrong. He always wanted to be proven. Yeah. So, and yet as yet all tests have proven him right. Yes, with a very high degree of precision. So what it might show is that Einstein's relativity is only part of the story. In a similar way to Einstein's theory of relativity, the general theory, which is all about gravity, that showed that Newton's theory was only part of the story. Newton's theory works really really well until you get into high gravitational fields and it doesn't work at all. But you didn't know about how gravitational feels and it works really well, but and it's well enough that it is telling us part of the story, but not the complete story. Maybe the same is true with general relativity, with Einstein's theory, that part of the story, but not a complete thing. One more point with hubble tension. Somebody is going to ask the question as to whether or not the influence could be dark energy or dark matter or both. Is that a possibility. Well, they're all taken into account in these calculations, you know, we we do know about them, but they're all taken into account. Sorry, that's somebody with the answer. Hope it is. Where my phone's gone? All right, just stop ringing anyway, So fair enough? All right, Well, it's it's one of those questions that will remain mysterious until somebody somewhere who will probably win a Nobel prize comes up with that light bulb moment, possibly a standard candle moment, Boombo. We'll have to wait and see. With the cosmic microwave background radiation diminishing, I assume it's diminishing. Will there come a time where we can't rely on that anymore? It's diminishing in the sense that that that radiation that we see that sort of wall of radiation, which is what it is that is actually moving away from us at the speed of light. But and and over time, those patterns what we call the baryonic acoustic ostellations, which you refer to the patterns in the in the wallpaper, they will change. But we're talking about millions, if not billions of years, so we've got a bit of time to this. We've got time to work on it. Andrew, all right, sounds good. We need it, Yes, sometimes we do. If you would like to read up on that story, it is a really fascinating read. It's Science alert dot com. This is Space Nuts. Andrew Dunkley here with Professor Fred Watson buds Now. Fred to a discovery that has been confirmed and there will be no doubt, and that is a major announcement at the fifty fifth Lunar and Planetary Science Conference in Texas the other day that they have discovered a new volcano beyond Earth and not surprisingly, it's on Mars. It's a monster and it's been in our face all this time. We just haven't really noticed it, probably due to weathering or erosion or whatever you want to call it. But yes, a new well it's not new, but it's new to us. New volcano on Mars. Yeah, I mean we know of several volcanoes of Mars, and including the highest mountain in the Solar System, Olympus Mons, twenty three kilometers high above the plains of Mars, a huge, huge volcano. And this new discovery, which I might just mention at the beginning of our chat about it is is by Dr Pascal Lee, who's a planetary scientist with the Seti Institute and also the Mars Institute based at NASA Ames and he is the lead author of the study. So what Pascal and his colleagues have done is looked at many what you might call aerial photos of Mars, the you know, the the images imagery taken from orbiting spacecraft of which there have been many since Mariner nine in nineteen seventy one, and combined it with the radar measurements, the basically measurements of the height of the features on Mars's surface, which have come from other spacecraft Mars Expresses one that's got radar on board. That's the European so sorry, the European Space Agencies spacecraft Mars Express and others too. So they've built up a topographic map of Mars, and what they've looked at is a region which is called Noctis Labyrinthus or Labyrinthus, and that name gives it away. It's a labyrinth of features, basically features of the night, I guess because notice is what that means. So it's essentially what you might call a tangled area of geology, the Labyrinth of the Night, named back in the early days of Mars exploration. But so it's easy to see why people have missed this. But when this group of scientists have looked in detail at actually the sort of eastern end of Notice Labyrinthus, they find basically all the symptom symptomatic structure of a volcano, an arc of mesas of raised hills which slope downhill away from the high area, the summit area, and this extends out more than two hundred kilometers away from what they actually speculate was the Cold era, the volcanic vent probably once containing a lava lake. We see lava lakes actually on Jupiter Moon EO. We can see their effects. They're real. So we think that the scientists think that this caldra on this new volcano or newly discovered volcano also contained a lava lake. It is being called the Noctis volcano. That's the name that is being given to it because it is so close to the Noctis Lebrinthus region. Fantastic discovery. Really extraordinary, isn't it? Yeah? It is, And it's a big one. It's over nine thousand meters in height and a diameter of four hundred and fifty kilometers or two hundred and eighty miles and the speak American twenty nine six hundred feet from sea level I suppose to the summit. Do we call it sea level on Mars. No, it's got some weird name like the standard day or something like that, but it's it's it's just a you know, standard measurement. And it's funny though because curiously, you know, the northern hemisphere of Mars is generally speaking below that, uh, and we think that the northern hemisphere of Mars once had an ocean in it, and so that datum is probably not far off what would have been sea level then, even though the sea's gone. But the but the you know, the standard is the same. So yes, that that's the bottom line we're measuring it. And in fact. I think in this case it's probably at the local topography or this volcano, the newly discovered one, and the major of other volcanoes that are on Mars, including Olympus Mons which is on the edge of this area, but this three other ones, Pavonia and two more. They are in a region that's called the Tarsis. The tharstest rise that Tarsis depending on how you whether you're correctly pronouncing it or not, it's it's a high, high level region and that the thinking is that this was a sort of bulge caused by magnetic pressure underneath that gave rise to the Tarsis rise, and the volcanoes have popped out through that. Olympus Mond is on the edge, but not you not, this volcano is also on that high high ground region. So it's fairly you know, it's a fairly good place to look if you're going to try and find a new volcano. This region where there's a bulge probably caused by a magnetic pressure, is a good place to look. And the other curious thing about it is that it's at one end of the valley's Marinaris. Yes, so I noticed that, correct, you know, I was going to bring there that. But it's quite a fascinating part of the planet around this is around the equatorial regions, I believe, and you've got Vallas Marinaras, you've got the new volcano, you've got a string of three to the west, and then Olympus Mons on the edge of that region. It's a really amazing area, it is. That's right, So Valles Marinaris, the Marina Valley's biggest canyons in the Solar System as far as we know. But exactly as you've said there at one end of it. It makes it look very much as though, you know, back in the times when Mars was warm and wet, It's water flowed one way or the other and probably away from the notis volcano down towards the low regions in the northern hemisphere of Mars. So yeah, we're kind of building up a picture of the of the early geography of Mars. It would have been quite spectacular with the volcanoes and gigantic canyons. One a time to be off Mars with a camera and yeah, absolutely. The other interesting thing that's come up in this story is that of glacial ice. And they're already talking about this new discovery being a potential location for a landing zone because of some of the potential resources and what other information might be able to be gained from the kinds of things that you might discovery. Yes, they've already identified a possible landing site there. But you're right, and this glacier ice is thought to lie underneath some of the volcanic deposits, so you know, it's probably pre dates the volcanic activity. That means it's going back almost to the dawn of the Solar system three point eight, three point nine, maybe four billion years ago. Really extraordinary, extraordinary discovery, is there. Fantastic work by this team of scientists' they've identified all kinds of volcanic features, you know, the sort of stuff that you get, things called rootless cones, which are basically mounds that surround a volcano, the various lava flows, pyroclastic deposits, that's all the you know, the the rock and dust that comes out of a volcano. We hear about pyroclastic flows on on our own planet, which are very very dangerous because they've got carbon dioxide as well in the atmosphere. You can't breathe in them, but there's ash, cinders, pomis, all sorts of stuff coming down and it's all there in this region around the Octis volcano. So superpose of work, I think, indeed, yes, and worth a read. You can catch that story at the fizz dot org website. That's the end of this particular program. And don't forget if you would like to follow us up at any time, jump on our website space nuts dot io or space nuts podcast dot com. We'd love for you to have a look around. And don't forget if you want to become a patron, that's the first pool to call our website. And don't forget if you're a YouTube follower to hit the subscribe button button below because more subscribers the better. As it turns out, I don't really understand it, but all comes down to statistics in the end. And Fred, that brings us to the end. Thank you so much. It's a pleasure. Andrew, you haven't done the pointing down to the button trick there, but that's where you press. Yes. That's one. Yeah, very good. I'll see you next time. Maybe it's a Q and a session sometime. Okay, it's very possible for it. Thank you Professor Fred What's an astronomer a large part of the team here at space Nuts and hoping you can join us on our Q and a episode coming up very very soon. And thanks to Hugh in the studio for what I do not know, but thanks anyway, and we'll catch you on the next episode of Space Nuts. Until then, Bye bye, thank Spacenuts. 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