#445: Snowball Earth Theories, Dinosaur Asteroid Origins, and the Hubble Tension Resolved

Hi there, thanks for joining us on another episode of Space Nuts. Andrew Dunkley here, and it's good to have your company. Coming up on this episode, we're going to be looking at Snowball Earth. There was a time where it was just a frozen sphere of nothingness for well billions of years. Now they have a new theory about that, and it's no Irish joke. There's a clue in there. The dinosaur asteroid's origin has been revealed. Yep, the thing that started the getting rid of them all across the planet. We know where it came from. And the so called crisis in cosmology might not be a crisis at all. We're talking about the hubble tension. We'll talk about all of that on this episode of Space Nuts fifteen in Channel ten nine ignition sequence Space Nuts or three. Two review on space as When I report it, Neils good and. To help us unravel all of that, decipher it and use his codebook to figure a few more things out, is professor I've Fred what's an astronomer at large? Hello Fred, Hello Andrew, keep up the good work there. It's going very well. It's good to see you now. I just I thought i'd sort of start out a left field because I spotted a story only today actually which dovetails with something we talked about some time ago, and that was the work that's being done to perfect engine technology to achieve greater speeds for interstellar travel in years to come, or maybe not interstellar but into planetary perhaps. And we know NASA is working on this kind of technology to create really fast and high performance engines. They're working with I think it's general electric to achieve that. They may have been gazumped, Fred, have you heard about this? Uh? No, the Chinese. The Chinese claim to have developed a new engine that can achieve a speed of twelve thousand miles per hour or nineteen seven hundred kilometers an hour, and the aircraft can reach an altitude of thirty kilometers. Now you compare that to the concord. It's Mac sixteen versus Mac two, which is an extraordinary claim. Now, apparently they've released a paper which has been peer reviewed from what I understand, and it's not April or first, I'm confident of that. So they reckon that they've made this leap in technology to develop a Mac sixteen engine, And just think of this thread, you'd be able to fly from Sydney to New York in fifty minutes. Yes, fifty minutes. That's extraordinary if it's real, and I don't see why it wouldn't be, but you never know with these things. But apparently, according to the paper, the engine operates in two modes. There's a continuous rotating detonation engine, which is a scary thing in itself by the sound of it, which will get it to mark seven and the air and the fuel create a rotating shockwave with continuous thrust. And then a straight line oblique detonation engine which fires above mark seven and pushes it all the way to mark sixteen. It sounds amazing, sounds amazing. How far short they are of getting this into production, I don't know, but it certainly sounds like it's in development. That would be amazing to be able to achieve those kinds of speeds. It would revolutionize travel around the world. It's been done already by yeah, the British have been working on this for decades now. With then it's an air breathing It's a hybrid engine that breathes there at low altitudes and turns into a rocket motor when you get above the atmosphere. Yeah, I think I did hear about that. I did not go to those sort of space. Yeah, well it can. It's capable of entering orbit, so it can get up to you know, twenty six thousand kilometers an hour. But it's then acting as a rocket motor, so it's the project was called well hotel was the style of thing, horizontal takeoff and landing, so it flies like a plane, takes off like a plane with the air burning jet engines, just gradually accelerates, clicks over into being a rocket motor when the atmosphere gets too rarefied, and then sends you up to orbit. As I remember right, I think it's called the saber the engine if I remember righter. But the big problem was keeping the air cool, and there was some The main breakthrough was apparently a heat ex changer that could bring the temperature of the air down from seven hundred degrees celsius or something to liquid nitrogen temperatures in something like a thousandth of a second as it passes through the engine, And that was a big breakthrough. Now we've I think we've spoken about it before a long long time ago, because I haven't really been much News. It was being supported by the British government. I don't know whether that support has now dwindled, because it would be you know, the idea about this was economics. It was to be able to have the same spait spacecraft that will take you up there and bring you back and was completely reusable. And to some extent, I think Elon Musk's Base X and the Falcon Nines have kind of cornered the market on that because they've now got reusable spacecraft which are routinely being used every day almost so maybe there's no space for it. But yeah, extraordinary technology, and I'm sure the Chinese technology is above board what you've just been describing. Yeah, it's from the Beijing Power Machinery Institute and they've published their paper in the Chinese Journal of Propulsion Technology. I can see a problem with it, though. Let's say they do create an airliner that can do that trip in fifty minutes from New York to Sydney. For example, you'd leave at seven o'clock in the morning in New York. You'd arrive at eleven pm fifty minutes later in Sydney. So you get up and get on the plane and then get the Sydney and then have to go to bed right away. Yes, that's right. That's the issue, always the issue. It would make jet lag all the more worse. Do you know, I think I'd put up with that rather than all those hours twenty hour flight. Yeah, I've got one of those coming up very soon. Thing you do. Yeah, but yeah, to watch this space story. But I just find it fascinating these kinds of leaps and technology. Let's move on a new theory about snowball Earth's fred I said, there's there's no Irish joke attached to this, and there's a good reason I said that. Which I'm probably going to slide step completely. It's about rocks in Scotland and in Australia. I thought it was. I thought they said there was some of these rocks in Ireland as well. Yeah, I think I think there are. I think that's I think. That's the loose connection I made. With it also includes rocks in Namibia and North America as well as Scotland. You're probably right Ireland in Ireland because it's the west of Scotland where these where these rocks are that have recently been analyzed, and I mean it's an interesting story. I've often wondered about snowball that I've never really looked at the details of it. So it's a period of about sixty million years ago, sorry, sixty million years long, but it was a long time ago. It began seven hundred million years ago, in fact, probably more like seven hundred and twenty million years ago, and lasted until about six hundred and thirty five million years ago. And it's called the Cryogenyan Cryogenian geological period. And anything with cryo in the front of it means it's frozen solid and so and so I thought, well, how do we know this? And the way we know it, and the way we know that glacial ice covered the whole planet is because you can see in the geology the effects of glaciation everywhere. It's not just you know, I grew up in a country where ten thousand years ago the whole of the northern part of Britain was under ice, and so by all my school lessons were about glacial features in the north of England, and so you could tell from rocks whether something has been glaciated, and that's how we know everywhere there is this layer of rock corresponding to looking back, you know, six seven hundred million years where you see the evidence of glaciation, and so the interpretation of that is that you had an ice age that was the put the grandfather of all ice ages. The whole planet was frozen. And so that the new research concerns evidence from rocks in Scotland. And what's remarkable is that the sort of glacier, the glacial evidence there shows up really clearly. For some reason, that has been preserved very well there, you know, underneath the sediments that were dropped on top of on top of it later on. But the bottom line about the reason why we got this ice age is a question. I'm not sure that in the article I sent you it goes into detail about it. But the thinking is that we were seeing a period or before this period, we were seeing a time when volcanic rocks were being eroded. They were being weathered very rapidly, and apparently these were particularly in Canada, these volcanic rocks, and looking back now perhaps seven hundred and twenty million years, they were eroded by weathering and that process sucks carbon dioxide out of the atmosphere, and so what you're seeing is a situation where the atmospheric carbon dioxide is lower than normal, and in fact it is probably it was probably about half what today's level is. Today's levels in the region of four hundred parts per million if carbon dioxide in the atmosphere, and that's enough to blanket our planet and keep the temperature stable unless you put more in, in which case the temperature goes up, as you know, but if you drop too far down, then you get an ice ball. They estimate the atmosphere carbon dioxide levels back in the cryogenic period or Cryogenonian period, they estimate they were below two hundred parts per million. And what that does is lets the heat just radiate out into the interspace and you lose heat. The Earth's surface becomes very cold, and basically you get the snowball Earth. You get an Earth that is covered with ice. It's the same sort of thing that we think happened on Mars. Mars is very low carbon dioxide content, and that's why we think it got cold and dry rather than as it once was. The other There's a lot of moving parts to this story, but one of the things I found most interesting was that if this mega freeze hadn't happened, life as we know, it may not have developed, it happened at this time. It was just microbial just that was it. That's that's correct. So and the thinking, yes, it was. It was single celled organisms until that time, and they were around for you know, three billion years or so. Nothing happened except these single celled organisms, principally cyanobacteria. They just did their thing and got on with life, but didn't evolve in any way. But the end, this end of the glacial period was such a sort of rapid climate change by the standards of the time, by geological standards, that the thinking is that you've got almost an arms race to adapt to this new situation where the microbes are not permanently in deep freeze. You've got a warming climate, and the evolution of the microbes kicks in at a much higher level than it was before. And that is where we think that the multi celled organism started to be formed. And that's what are the ancestors of all the animals that we see today. Yes, so basically those who survived the thaw or adapted to it created. Life as we know. It just an extraordinary sort of factor to come out of it. The other thing, I correct me if I'm wrong. But these rocks we were talking about in Ireland and Scotland and Australia and everywhere else. The reason that these are so different is I believe these were rocks that actually stuck out of the ice. Is that correct during. That yes period that they may have done or at least been subject to less placier activity. So yes, they may have you know, had only a thin layer of ice over them, rather than be under kilometers of ice. So I think you're right there. And just to confirm you quite right that some of these rocks are in Ireland as well. Hadn't spotted that Andrew in my reading of the paper. But yes, so you've got particularly you've got these rocks on some of the Scottish islands. These are small islands called the Gavelos and it's basically in the west of Scotland. It's under the Potaska Formation. This is a geological area. Potaska very well known to Scott's people because it's the name of a well known pipe tune. So let me quote from one of the authors of this work, and he's actually a PhD candidate at the University University College London. The layers of rocks exposed on the Garvelis are globally unique. Underneath the rocks laid down during the unimaginable cold of the glaciation are seventy meters of older carbonate rocks formed in tropical waters. These layers record a tropical marine environment with flourishing cynobacterial life that gradually became cooler, marking the end of a billion years or so of a temperate climate on Earth. Most areas of the world are missing this remarkable transition because the ancient glaciers scraped and eroded the way the rocks underneath. But in Scotland, by some miracle, the transition can be seen, and I think that's underlining what you said. They were either sticking up through the ice or they weren't particularly deeply covered by ice. So it's minerals and radiometric dating of the minerals that have allowed this discovery to be made. Yeah, it's incredible, isn't it. All The answers are right there in front of us in the dirt. Sometimes simple that that's how we we know so much about the history of not just our planet, but the you know, the other. Planets of the Solar System. Just learned from looking at the rocks. That's right, Yeah, fantastic. If you'd like to read the article or chase up that story, it's on the Cosmos magazine dot com website. There's a space Nut's Andrew Dunkley here with Professor Brad Watson. Murder your spacebuts. Speaking of dirt, Fred, we've got the dirt on the dinosaur asteroid. We we now know thanks to a new study where it came from. This is fascinating too, it is. That's right, and you know, it's not that long ago that people were really still speculating about where the remnants of this asteroid was. We're now pretty certain that it's in the Chickalog Basin in the Gulf of Mexico, that that is the site which actually was the impact site of this asteroid. So what you can do is you can look at the rocks that you find in that region. Once again, we're looking down at the dirt, but basically look to see whether we know of anything like it out there in the Solar system. And the bottom line is that yes, we do find that. In particular, and this is work being done at the University of Cologne in Germany. The. Element Ruthenium is basically a chemical marker. Put it that way. That is found in the debris around the Chick Salam impact and apparently in other sediments around the world, because the debris from that explosion spread all around the world. It was so, you know, such a major piece of piece of explosive material. It was only explosive because it hit the ground at a very high speed, probably thirty or forty kilometers per second. But the fingerprint of ruthenium has been found in that debris, and it turns out that that coincides with rocks in the Maine asteroid belt, that's the region between Mars and Jupiter, but at the outer edge, outer edge of the asteroid belt, not sort of not the kind of place you'd expect. You would think if that rock had come from the asteroid belt, you'd think it will be near the inner edge, but the chemical specifics tell you that it's actually at the outer age. And that is really very very interesting deduction. Who would have thought that we will built a pinpoint where that asteroid came from sixty six million years after. The event, and maybe the asteroid yeah, I guess they worked it out on the chemical composition elements rather than backtracking. Yes, that's right, it's we don't have enough information to backtrack. We don't know what anglic came in at or you know what it's all of it was before it collided with Earth. So it's all about chemistry, is this? And and in particular some quite quite sophisticate Well, I suppose you call it chemical physics, because they're using radiation techniques basically to look for these levels of ruthenium in the basically in the debris from the from the asteroid creator and surroundings, and basically, you know, looking at how it compares with other asteroid impacts and carbonaceous meteorites which also come from that region of the Solar System. So what might have caused a rock from that particular part of the Solar System to you know, turn its attention to us. Did Satain get upset in check a rock at us or something? It's probably it's probably a just a gravitational disturbance, you know, something that disturbed the orbit of this asteroid in its comfortable zone of the asteroid belt. Maybe an interaction with another asteroid, because when objects come together they needn't necessarily collide. But if they can interact with each other gravitational so that one of them gets thrown out of its orbits, and you know, it's possible that that would have been the case. It's kind of like being in a crowd at a Chinese supermarket. Really, That's that's what it's like. Yes, yes, I didn't want to go that way, but you ended up you have to you have to go that way, Yeah, just because everything's so crowded. It's it's a bit like that. The The thing is that that event, whatever tipped it out of its comfortable orbits, that might have happened a long time before the sixty six million year day ago that we have for the for the impact for the extinction of the dinosaurs. So it might have been in a in an orbit that intersected the Earth's orbit for a long long time before the crunch finally came when it tried to be in the same place at the same time as the Earth. So yes, so we there's details for this story that we still have a long way to finding out. But it may well have been as I said, it's either a collision with another asteroid or maybe even something like the gravitational pull of gas giants. Maybe Jupiter perturbed that objects orbit in such a way that it interacted with another asteroid and got thrown out of turned out of the asteroid belt. We probably will never know that. It's interesting enough, I think, to discover whereabouts it came from. Yes, the other thing that came out of this is that it all bat writes off that this was a comet impact. Yeah, but not absolutely. Yeah, that's right. There's still there's still a possibility. But you know, comets a different beast from asteroids. There, they've contained lots of ice as well as the rock, and that means that the chemistry of the residual material from the impact would have different properties. So I think it's you know, you can never say never, but the the the body of opinion seems to be that it was actually an astrolier rather than a comment. Yeah. I do have just one more question about this story, and this is the most important one for it most important. You mentioned the element. So was the person who discovered that named Ruth. That's a good question. I'd have to take that one to notice. But my guess is that that's where the name came from. Maybe maybe it was somebody who was ruthless. They thought, yeah, I'll call it ruthenium because I'm ruthless. Who knows. Yeah, that's that's a thought to that story. If you would like to read it is available at space dot com. This is Space Nuts Andrew Duncley here with Professor Fred Watson. Space meds Now. Fred to the so called crisis in cosmology. We're talking about the the Hubble tension. Now we've we've done this story a few times over the years. This is where the basically the expansion speed of the universe, depending on how how you calculate that number, comes up with two different answers, and they've never been able to figure out why. But now they're starting to think, well, there's no crisis at all. Everything's right, Yes, So. Let me just explain how this this tension, the Hubble tension comes about. Yeah, because there are two ways of measuring the expansion of the universe. One uses standard candles and the other use is a standard ruler. And put it that way, so the the standard candles. Taking that first, if you know how bright your candle is, then you can work out how far away it is from you, because you know, you know it's real brightness. It's intrinsic brightness, then you can work out what is going on in terms of because we know the way light gets fainter. We know the rule by which light gets fainter as you move to greater in greater distances. It's what called the inverse square, or it goes as the square of the distance one over the square of the distance. So standard candles are usually stars in galaxies, and in fact this is what led us detect the expansion of the universe in the first place, because in the early years of the last century, around nineteen hundred, a group of astronomers in the United States measured the intrinsic brightness of a particular kind of variable style, one whose brightness varies, but it varies in a in a periodic way. And it turns out that there's a relationship between how frequently it varies and what the intrinsic brightness is. And you usually take it at peak brightness or minimum brightness, which doesn't really matter as long as you know what it is. And so that's the time honored way of working out how far away galaxies are. To look for these variable stars and then basically look at you know, how bright they look to us and from that work out the distance, and that lets you produce a value for what we call the Hubble constant, which is the number that basically tells you how fast the universe is expanding. The Hubble constant is in units of kilometers per second per mega passe, but we don't really need to worry about that because at the moment, all we're interested in is the number. And so until now, the best estimates from the standard candles, in other words, the Cepheid variables have come out at about seventy four kilometers per second megaparsec. But then the standard ruler method is looking back at the flash of the Big Bang, the cosmic microwave background radiation, which we see as it was about thirteen billion years ago, and there are features in that variation which have separations that we know would be characteristic of a certain particular time. And what we're talking about here when I say features, I mean peaks and troughs in the temperature of the Big Bang. Effectively what you're looking at, and from that you can also deduce the Hubble constant the expansion rate as it is today. But the answer you get from that is sixty seven point five kilometers per second per mega passe eg, which is round about six and a half kilometers per second per mega part sect different from the other one, and that is now we're in such a precise era that that now has people worried. So what's happened. Well, the same team who've done a huge amount of this work in the past, led by Dr Wendy Freeman Friedman, one of the big names in this kind of science in the United States. Wendy and her team have used our new toy web, the James Webspace Telescope, which. We always knew it would it would solve this problem. We knew it would certainly help. It would either make it worse or it would solve it. And yeah, you're right to cut to the chase. It's probably solved it because it's now looking as though the method is more like that, you know, the method where you measure the brightness of these variable stars is giving an answer more like seventy kilometers per second omega passe, which is much closer to that sixty seven point five that you get from the cosmic microwave background radiation. And it turns out that when you think about the error potential eraror of both of them. Then it overlaps. So in that regard, you've got something that falls within the air bounds of both of these methods, and so maybe we are seeing the right answer at last. So it basically brings it back to an average. That's right, that's rights. Yes. You know, when I started my career, Andrew, there were two camps and basically they were using similar methods. One said that the Hubble constant was fifty kilometers per second per mega pass. The other said it was one hundred kilometers per second per mega past second. They were both right. I thought they were both right, and it turned out that the answer, the real answer, was the average of them with seventy or five of the. There you go, pretty simple solution at the end of the day, but a lot of hard work went when in fine and yeah, we. Hope that's that resolves the Hubble tension. It will be gratefully cosmic class disappeared. Yeah, yeah, I wouldn't be surprised though. In months to camps somebody comes up with a debunking theory. Well, there you go, it couldn't happen. It could happen at this point in time, looks like it might have been resolved. This has been frustrating for a long time, but maybe as simple as hang on a sec. You're both right, and here's why. Yeah, that's stories on SYE Tech Daily dot com. Question without Notice spread that's come through from one of our live viewers, Wayne high wayIn this harks back to the snowball Earth story we did. Wayne, I wonder how much bigger the diameter of a frozen Earth would be to the current Earth. Do we have any idea what that might have been. Yeah, it probably wasn't that much different. It's you know, I mean at the moment, a lot of that water is still there, but it's wet. You know, this is now it's turned into eyes, so it's not going to be it's certainly not going to be tens of killer meters different. It might be a few killo meters different on average, and I'm talking about the average. But I don't think it would you know, it wouldn't have turned into a gas giant or anything like that. It's an interesting question though, because we think it's because of frozen water out in the depths of the Solar System adding to the mass of the gas giants. As they were being formed. We think that is one reason why they became so big, because they had enough bounds to hold on to a gas envelope. And so it's a good question to ask that at what difference would the ice blake. But this is really just a surface layer of ice rather than a solid block of ice, which may be at the core of the gas giants. Indeed, all right, thank you. Why nice to get questions without notice while we're going out live during our recording sessions. Good to hear from you, Fred. We're just about Dan. Thank you very much. A pleasure, Andrew, good to talk and some interesting topics, and there'll be more next week. Indeed there will, Thanks Red Professor Fred Watson, Astronomer at Large. I don't forget to check us out online Spacenuts podcast dot com, space Nuts dot io. We can check out the shop, maybe become a supporter of the podcast if you're interested, just have a bit of a flick around. And if you follow us on social media, don't forget to like us, follow us, add us to your favorites list, or click the subscribe button depending on which platform it is. And thanks to Hu in the studio as always and from me Andrew Unkley. 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