159: Intergalactic Radio Waves

Automatic TRANSCRIPT

In fifteen seconds guidance internal Chan nine ignition sequence, Spence nuts. Spence nuts. Three four five three two one. At the not reported feels good. Hello yet again. Thank you for joining us on the space nuts podcast. My name's Andrew Dunkley, your host, and with me as always is professor Fred, Watson, astronomy at large hullo, Fred Andrew, how you going very. Well, how are you? Yes, I'm surviving nicely. Thank you. It's good to hear. Danley minutes since you told me. Anyway, let's talk about this week's episode episode one hundred fifty nine of the spice nets podcast. We got to look at a situation that I find quite surprising, but having worked in radio thirty five years, or whatever it is and radio is very common radio. Waves are very common in the universe. But now it's been discovered that they might be a ridge of plasma emitting radio waves, connecting to galaxy clusters which just sounds mind boggling, when you consider that the limit of radio signal in spices, fifty light years or something. So this, this is rather fascinating. We will also knock off a couple of questions in what is yet? Another shortened version of our podcast. We got to look at a question about, doc matter pushback from Dr Robert, Scott. Thank you, Robert, and Kevin Rutherford's asked us about the Michelson Morley experiment. Expand. Could be the michelson-morley experiment, depending on how you pronounce his name. But. It looks like Kevin's detected could be a contradiction in that experiment. And well, we'll, we'll investigate that tiger a little bit of work to figure that one out. But first, Fred, let's look at these, these radio waves that same to be sort of working between these two galaxy. Clusters sounds rather fascinating. It does indeed. And it's something that's been suspected for decades, actually that we would find something like this. And it probably means we will eventually find a lot more of these. So what's happened is that two clusters of galaxies. And of course, galaxies are these huge aggregations of stars and gas and dust, one of which we live in coal the Milky Way galaxy but we know that galaxies coming clusters, two of them, which have been studied in data will have shown a, an interesting thing between them. These two galaxy clusters. The, the not close together that, that, you know, they are relatively close together on the sky. But when you look at the scale at you talking about this is millions of light years apart that they are eight maybe a little bit unexpected that you'd find the bridge of material between them. But clearly people have been expecting this because astrophysicists have been looking for it. So the two galaxies rejoice in the name of I- bell zero three double nine zero four zero one, and you might notice those numbers early to apart which tells you that these two clusters next to one another galaxy clusters, by the way, I usually they usually have the name a ballet in front of them because they were catalogued by an call Joe J bile, who did a lot of these work in the nineteen eighties. She knew he spent some time in Edinburgh, the all observatory where I was working, because he wanted to use some of the photographic material that we had to identify his is galaxy. Clusters. He was a delightful man is no longer with us, but it's nice to season him cropping up every time you talk about galaxy clusters so bell, three nine nine able 4._0._1. these two galaxies, which may well, be about to merge together in other words undergoing a collision, but what is being observed is a bridge of material between them and it's, it's plasma as you said, it's a it's basically energized atoms and the interesting thing about it. And I think this is why this has become such a big story is that to have a plasma like that you need magnetic fields to, to excite it until the ridge tells you that the there is magnetism, connecting these two galaxy clusters. And that's a magnetic field over a very, very large distance. They so if you think about a Bama Ignat, you know, the kind of thing you might put in your pocket. This is something like that. But he's ten million light years long. So. Is the plasma? So it feeds into trying to understand how magnetic fields originate, and, in fact, that's what a lot of modern astrophysics bow, where magnetic fields, come from. It's one of the reasons why a stray Leah is involved with the square kilometer right project, the largest telescope in the world, which will be completed within the next decade in two places one in Western Australia, and the other in South Africa s K is the next big thing in radio straw, me and they will certainly be using that facility to look for bridging magnetic fields between clusters of galaxies because among stated intentions, the stated aims of the S K is understanding the origin of magnetism in the universe. Now it wasn't the Esca that was used for these survey Sion's, but it was a sort of. What you might call a distant cousin of the s k thing called Lofa low fire is the low frequency array. So it's a set of radio telescopes looking at low frequencies from the universe is still is still VHF bound is far as we're concerned in terrestrial communications. But that's low frequency for for astronomy. Low far is actually located in Europe. In fact, in several sites in Europe. I visited one of them some years ago, which was non saying in northern France. And it it's like it looks like a just an array of poll stuck in the ground. It's not elegant dishes or anything like that low far only needs relatively simple antennas, but there are many of them as indeed. They ask it will be yes K, we'll have hundred thirty six thousand ten shape like small Christmas trees are actually shed like large Christmas. Trees, made our Benko hung. Is that's what it looks like. But, but he's very high tech stuff on by this out of there. That's right. It's probably got big civil current as well. I can tell you actually that when they made the prototype of that. And they used to actors have base for, for each of these antennas, and the several thousand ten is in the prototype, model the Pathfinder, they actually used a concrete slabs with holes in the middle, which they bought secondhand from the post office in the United Kingdom. Because they were they were telephone manhole surrounds, you know, you have a manhole cover way at the bottom of the holy you've got these telephone cables with a metal cover on it, while this, they've got a concrete surrounding, and somehow the square kilometer array, people found a cheek deal to buy a couple thousand of these manhole cover areas. Yeah. That's that was the base of their of the base of their prototype right now to change the design because they realize. Is that for hundred sixty hundred thirty six thousand of these things it was going to get very expensive in second non hills. So they thought of another way. Debate anyway. So that will be what they love frequency square kilometer array. Component in a strategy will look like but lo fi has, as you know, the one in Europe has essentially made this great breakthrough that we found the fields between clusters of galaxies. I'm sure the story will move on as the squad killer Mehta awry evolves. We might find that there there's a web of magnetic fields, connecting all galaxy clusters that could be one of the discoveries that might be made and that would play in directly play into trying to understand where my take fields, come from opens up a question in my mind because as I understand it. I Bill, I three non non L for I one merging. Yeah. And Al galaxy is guide to merge with the drop of the galaxy. So one wonders, if we'll start sort of exchanging these materials it could be. It could be already happening, Andrew because that will be something that. From our vantage point will be very difficult to detect I do have friends in the in the business, though, who are specialists on, on cosmic magnetism might ask them about it, because that's a really good point that maybe galaxy Andromeda which are closing on the speed of is, I think it's around two hundred kilometers per second that closing speed means that they're on a collision course that may already be a bridging material between them that links them in the way that we say these two galaxy clusters Ling really interesting coming well done. Thank astronomy papers, not. Short. An identity dead qualify, but only so two hundred kilometers per second merging. Right. And and how long before the merger happens. It's about three and a half billion years, really does let you know how big the space between. All right. You're listening to space nuts, Andrew Dunkley here with professor, Fred. What's in? Space butts now Fred before we get onto today's questions, something's popped up in the news, which is rather extraordinary, we've, we've talked about space tourism and the organizations, private organizations that are looking at putting people into space sub orbital flight that kind of thing, people get to experience for two hundred thousand dollars a pop or whatever it is zero g for a short period of time, and then glide back to worth we'll get rocketed backdoor or whatever it depends on who they go with us oppose but now Nassar's playing the game. Yeah, that's right. And I guess, this e can put it in context, the context is that the current US government administration sees the private sector, essentially taking over the space station within the next decade. Or so it may even be before that Bobby, where the next five years the. That. Nasa wants to open the station to private industry and that they will eventually private industry will take over the running of the, of the space station for whatever purposes, might be deemed necessary, and one of those purposes could well be tourism. So this is sort of opening gambit in the in the private sector for NASA to start. You know, start opening up the possibility of space tourists now to ease the transition to the from the private sector to the commercial. So from the publicly owned sector to the commercial sector. So we've got the deal that you can now buy. You could buy a holiday on the international space station as you've been able to do before you on this. Well, not really the space station itself. So for about a decade during the early two thousands, a company called space adventures bro- broke the deal between roscosmos the Russian space agency, but a few really wealthy people who wanted to go into space that because in those days as he's now, actually, well, no in days. While the shuttle was still flying. US astronauts were ferried up down to the space station with shuttle, butts, cosmos, went with the Soyuz, spacecraft, which was a three seater spacecraft, but only two or used so space. Adventures, did the stale where a passenger could fill the third seats at there were seven? I think there was seven takers for the day lease that was paid. We know was twenty million dollars for a few guys on the space station. Then it was probably more than double that for the most expensive one. The prices that have been quoted now though are a bit higher than that because. The, the ticket to get there could be as much as fifty eight million US dollars. This would come from an up one of the organizations that are going to be ferrying stuff up most notably SpaceX, which is interesting. I would have felt the price would have come down. Because SpaceX, of course, reuse that boosters, and that means that, that price per kilogram to gain to open should be cheaper anyway. That's the price that's being paid under. There is a daily rate for the space station of thirty five thousand US dollars per night. Not probably includes a Cup of tea in the morning as well. You kinda hope so, yes, yes. But you wouldn't be able to drink at lucky normally would know up six by Diller. He's not gonna out of plastic container or something with ROY. Yeah. So all right. That'll be interesting. I'm sure they'll be Titus all the way over four. I think it'd be marvelous, but you know what never going to happen now? Let's move onto some questions. And this one comes from doctor rob Scott who resides on the Sunshine Coast in Queensland, and no derogatory remarks remarks this time about the state of origin because it bit me in the face big dog. Now he says, if gravity can interact with the fabric of space time, gravitational waves could dark matter. Just be a pushback from this fabric on meta could this account for the high rotational speeds, some steadying force from the fabric of space, allowing higher speeds of matter without galaxies breaking apart me is? Yeah. It's a nice idea from rob. And I think he's I think he's thinking is is, is good. So I suppose what you could do is okay. We've got replaced with this problem galaxies rotate. Faster than they should be able to stay together. You know you see a galaxy he can measure rotation. You can look at it and see how much mass you think is there. But it turns out that if that solar is, then the thing should afloat apart. So there are two possible ways of dealing with that question. One is what is now the accepted standard version that there is this material matter which envelops the galaxy, and it's the gravity of dot matter that holds a galaxy together. But there is another possible interpretation, which was suggested very early in our understanding of dot must tell what you buck in the nineteen eighties more behind milligram. I think he's Tel Aviv university in Israel suggested that it could be that we've got our understanding of the way the dynamical forces work, and he'd propose something called mom, which is modified Newtonian dynamics now in a sense that aligns with what rob is suggesting. That you've got a what he calls a pushback from, from the fabric of space that would manifest itself as a force field, which could be interpreted as a modification of new Newtonian dynamics. So it it's it's got connections with what was proposed back in the nineteen eighties. The bottom line is that it doesn't work because the whilst you can use mum door sort of pushback force to interpret galaxies holding themselves together. When they shouldn't it doesn't work when you look at clusters of galaxies, and it doesn't work when you look at the volition of the universe as a whole, and that's the problem that these the idea of some sort of material dot matter is fully consistent. With everything else, we measure in the universe, whereas, modified Newtonian dynamics as it, and that's why it's largely been abandoned after say, and he might well, be listening to this podcast because I know he's a listener one of my colleagues is about to embark on a PHD looking at bummed. But if I do Tony dynamics. So maybe rob Scott in the Sunshine Coast, that Dr rob Scott will be happy to know that people are. Instigating still Besigye that we've, we've is our understanding of physics since wrong. Not the fact that there is some material that we don't we don't see so. Yeah. I think he's I think he's good. Good thinking, and you never know we will wait to see the end of pitas, PHD thesis in a few years time, find out where the mugged my actually be the answer could bay. Thank you. Rob your question. Really appreciate it. Now we turn our attention to a question from Kevin Rutherford, Kevin lives in Michael's field in the UK. And it looks like he's a kindred spirit of yours. Fred, he said, studied, the Michelson Morley experiment at school and indeed in first year physics at Sandra's university in nineteen seventy seven shortly after Fritz time, they, you bet seventy years before, Fred was there. After it was. Anyway. Briefly, does the Lago experiment contradict, the Michelson Morley theory, both experiments used interferometry to detect properties of whatever it is. That is moving through. And yet, one concluded there is no aether, while the other concluded that space time can wobble. Is there a contradiction or was the michelson-morley experiment? Not sensitive enough for its purpose. That's a great question. It's not a fellow since Andrew's graduate that good to hear from you Kevin this another connection with astronomy. They're of course Andrew because Kevin's from Michael's field in the UK. It's in the north of England toys pronounced Michael's field with a very short field. I Michaels field. It's where the judge will Bank radio telescope is very, let's field. So that pioneering radio telescope, the U K equivalent of our parks, here in Australia, is very close to Michael's field. In fact, you pass on them six if anybody's passing that way, but don't look while driving, because he needs -ly run into something else rather than the telescope. So they said quite a long way and great question. So okay, what is the Mickelson? No michelson-morley experiment. It's a an experiment, using light waves. And the idea was this was performed many many times. In the nineteen thousand of the eighteen eighties from the eighteen eighties onwards, because people believed that time that, that would be something called the ether and the eighth was supposed to be the component of the universe, which transmitted light. So, and the analog, of course, is the on, on the surface, we hear sound waves because sound is Trump is transmitted, by the atmosphere and so- physicists of the day figured that you needed something to transmit, light waves, and suggested that there would be an aether that was what it was called. It was the raw material of space, if you like that, that transmits, long wait so experiment to adults said, starting in the nineteen eighty s to try and measure this heath a what the way they were done was to use this thing called in into for almost actually it's usually called Michelson interferometer tickets that he's the guy who invented it. To show that light would have different properties in one direction as distinct from another. And why why did the twos? One two particular directions, while one of them is the way the earth is moving through space. And we know there is going, thirty kilometers per second around the sun. We also know that the sun is being carried at two hundred and fifty kilometers per second around the center of our galaxy so that the earth has a motion through space. And so the argument was that this interferometer should be able to detect that now, if the either existed that will be a very, very gross effect. The michelson-morley interferometer would show it up, you know, as it was being eliminated by searchlight it will be very, very obvious in that experiment, that there is an ether. And so that's you know. You know, that's that's why we recognized after the michelson-morley experiment that there isn't it? What is what led them to special relativity? Because we now know that the speed of light is the same no matter what direction you're going through. You seeing a moving through space. That's what the because similarly experiment did the michelson-morley experiment. Now, lie go the large interfere metric, gravitational observatory that you and I have spoken of many times is just a Michelson interferometer is the same instrument. But so if there was an eater. You know, the it will be absolutely overwhelmed by the signal from that. The fight the is moving through space. But what were detected now is just vibrations in space itself, which are at a much, much more subtle level? So I'm the last line of, of Kevin's question was the michelson-morley experiment, not sensitive enough for its purpose. The answer to that is no have they been in Asia. It would have picked it up because it said gross effect, but it was not sensitive sensitive enough by a very long way to detect gravitatational waves. They need the kind of exquisite sensitivity that we've spoken about with the MacOS with a lie. Go into parameter which can detect changes in length that amount to one ten thousands of the damage of approach Elvis, still just staggering stuff, so Michelson Morley. Experiment was no any of that kind of sensitivity. So there are no contradictions, but it's yeah. It's a really interesting question and a good thing to think about as well. It gets me getting my mind, but to second year first year physics, moose back in the day you were wrong actually about it being being seventy years before Kevin was to tell you that the university of Andrews was founded in fourteen thirteen. And I was there. Very shortly. Fair enough. Kevin also writes that he found if w initials in his desk. He's not sure what they meant. Anyway. Thank you for your question. Really appreciate it. And hopefully you go to bit more insight into what you were pondering about, which is terrific. And thank you, as always Fred, it's been a great pleasure as always. Thank you. You too. Drew. We'll be soon. I'm sure we will Fred Watson, astronomer at large and just a reminder, patriarch dot com slash space. Nuts. You can certainly subscribe to the space nuts podcast there. If you're an Instagram user, you can find out parent organization bites IT Zid HQ on Instagram. You can also find us on Facebook, just do a search for space nuts and YouTube as well until next time. Thank you, as always for your contribution to this little podcast and for listening in, and we'll catch you in the next episode of spice nuts. To this place. Nuts podcast. Subscribe to the full podcast on itunes and Stitcher or your favorite podcast distributed. This is another quality podcast production from dot com.

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