#438: Gravitons' Mysteries & The Sun's Hidden Twin

Hi there, thanks for joining us. This is a Q and A edition of Space Nuts. My name is Andrew Dunkley. Coming up, we're going to do some homework. Gus sent us a question a couple of weeks ago. It was so convoluted and complicated he gave up. But we'll really bit at that because he's actually come up with something very interesting. He might not have realized that we'll also be looking for the Sun's dark matter twin. According to Rich, other questions involving time dilation and dead stars have been sent to us, and a question we've done before we will revisit because Fred likes Anthony's accent. That's all coming up on this edition Space Nuts fifteen in channel ten nine ignition. Sequence Space Nuts or three two space notes A and I repot it. Bill's good here is once again to answer all of those questions and more, Professor Fred, what's an astronomer A large HIPH Fred. Let's start on an optimistic note that maybe we can maybe we can answer some of them. Yes, at least we have a homework department that can we can get We can always go back to them later, which which is what we're going to do today. Shall we just get stuck straight in. I think we ought to. Yes, all right, So our first job today is to answer some homework from Gus, who's sent in this question a few weeks ago. Hello, Professor Fred and Andrew. This is Gus Ever sent from Disakwa, Washington. I sent in a question for you guys previously, and you thought I was in we Western Australia. I've been thinking about gravity today and it came to my mind that if energy and mass are equippedent, then essentially shouldn't energy also create graph be at some level. I'm not sure if this is a related question or or extension or a separate question. Though. Additionally, if a body of any size is generating or it has mass and it is generating a gravitational. Field, does not that field itself have energy and mass? And would that field not create additional gravity by its simple existence? So if that's the case, or even kind of the case, my question is where does the energy and mass go? If or I have no idea where to go? Thank you? I love love the show and appreciate being able to ask. Thank you. Gus. Yeah, I kind of yeah, he ran out of puff, but. You know, we've we put this one on the back burner because there was a lot going on there, a lot of thinking, and Fred's done the homework and you've. Come up with an answer. In fact, you've suggested before we started that Gus might have been onto something. Yeah, I think it's doing pretty well with that sort of thinking. We did talk I think we covered part of this a little while ago. You spoke about if you if you've got, you know, a planet, and you increase its temperature by two hundred degrees celsius or something that actually contributes to its mask because you're putting energy in and so it would affect it's gravitational pool. But the nub of I think Gus's question comes down to the issue of whether the hypothetical particles, which we haven't yet detected and there is no theory to support them, but they are still doing the rounds. The hypothetical particles of gravity, which we call gravitons, I guess analogous to the fact that we call particles of light photons, which are certainly not hypothetical. We know a lot about them, and they certainly exist. They're definitely part of our big picture of the subatomic world. But gravitons aren't yet, but they are thought to exist. So that because gravity is one of the four fundamental forces of nature, all the others have particles associated with them, and so we expect gravity too as well. And eventually we were probably able to prove that gravitons exist and that they know that they are real, and that we can see evidence of them. So the issue that postulates the boils down to do gravitons themselves have mass? And the assumption has always been and this is because effectively that's what Einstein's relativity predicts, although it doesn't really talk about gravitons. But. The assumption has always been that gravitons are like photons, massless particles. They don't have a rest mass, that's the way to put it. So photons we know and don't have a rest mass. Gravitons are assumed not to have a rest mass either. But there is science that's going on. People are researching this and in fact i'm reading an article which is easy to find. It's on The Guardian's website. It's actually four years old, now four and a half years old, but it's about the work of one particular physicist who name His name is Claudier Dram, who's at Imperial College in London, and she has built a theory that postulates that gravitons have mass, and if they do, then they've got intriguing consequences and one of them is that they would have If they do have mass, then it would mean that their influence on very large distances, on very large scales is weaker, and that could account for the phenomenon that we see of the acceleration of the universe, the accelerated expansion of the universe, in other words, what we call dark energy. If you have mass, gravitons with mass, then that could explain the accelerated expansion of the universe. Fantastic thing, you know, that would be that would solve so many problems. However, and I'm going to quote from the Guardian article here because I love this this theory. It is what it says is despite successive efforts, previous versions of the theory had the unfortunate feature of predicting the instantaneous decay of every particle in the universe. So there is there's a drawback to it. And a quote from Claudia Iram, very clever people who'd worked on this and the arguments were very compelling. People thought it would be impossible to make it work. But well, there was a paper published back in twenty eleven which had a pretty hostile response from the you know, the scientific world. In other words, people saying, this is all ridiculous. It doesn't work. It means every particle in the universe decays instantaneously. So so it's still a work in progress. But the reason why it was in the news back in twenty twenty is that Claudier Durham was the recipient of a one thousand, sorry, one hundred thousand US dollar Blavatnik Award for young scientists, and it's one of you know, it's an award that is put in a place where people think it's going to the research is actually going to bear some fruit. She actually won the Adams Prize as well, which is Cambridge University very prestigious award. So it's still a theory. Massive gravity still a theory, but has attractive features. I mean, if you can explain away the accelerated expansion of the universe by having massive gravitons, that is brilliant, but especially if you can do it without everything else in the universe us decaying. So you know, it's interesting. And one of the other aspects is that you might be able to detect this by fairly subtle ways using gravitational wave detectors, and as they become more and more excuse me, more and more refined, and I guess the gold standard is going to be leaser that. What's it called large interferometric space. I can't remember what the A stands for, but it's an EASA project to have a space based gravitational wave observatory. It's if something like that had the sensitivity that we expected to have, then it may well be that we can one day say, well, gravitons have mass, and that would revolutionize our whole thinking about the universe. So Gus, you've done very well there in yeah an idea, even though you run out of steam as I would have done where where you were in the thinking. It's it's got some credibility. Laser intoferometer, space antenna. That's it. Thank you. Your answer to gusa's question is going to ask probably result in someone asking another question, which might be, Okay, we don't know that gravitons exist, or we just assume that we haven't identified them. But could gravitons be dark matter, uh, dark energy. For that matter. Well, well, yeah, that's what we're saying that they're saying there's no need for dark energy if you've got massive gravitons and they weaken their effect, weakens of the distance, So you don't need dark energy because the you know, the basically the gravitational pull of everything in the universe is weaker than we think it is, and that we could explain the accelerated expansion dark matter. Yeah, it's an interesting thought, except dark matter. Well, dark matter is something that's associated with normal mutter. I think I've got to think about that one a bit more. So there's more work from you, Andrew. Sorry about that. Yeah, okay, thank you, Gus. We finally got there. While we're talking about dark matter, here's a question from Rich in the UK, Hi both and Hugh in the studio. Great show, such a broad spectrum of information. You do a great job. Okay. My question harks back to a number of different episodes we've talked about the theory of our sun may have been born of a twin planet nine roaming about somewhere in there, and that dark matter is only measurable by its gravitational effects. So I put two and two together and came up with thirteen point seven. Is there any plausibility in the idea that the Sun has a dark matter twin somewhere in the vicinity, in the vicinity that could be demonstrating the effects we see on our Solar system instead of a planet nine rich from the UK, or maybe it's a town called Ah. I'm not sure. No, it's not like it's yes, so interesting idea. I mean, we've got no evidence of dark matter entities. Yes, stars for a star, planets for a second. And in fact, it was experiments done in the nineteen nineties, some of which were done here in Australia that ruled out the possibility of there being lots of dark matter objects, which we call black holes. Basically, it ruled out, you know, the dark matter was dense stars in other words, what were called black dwarf or rogue planets or black holes that we hadn't detected because they would have a signature on the stars beyond them, they'd have a gravitational lensing signature. And I think that will be the same if you had a dark matter planet, it would have a gravitational lensing signature, and nothing's been observed so far. It's true though that some people have suggested that perhaps Planet nine isn't a planet, perhaps it is a black hole, some tiny mass black hole something you know, Mutch, more than a star, which would suggest that it was a primordial black hole, one that was created in the Big Bang, not by the collapse of the star. So yeah, these are ideas I think that are floating through the astronomical community as well, So you're not thinking that far out of the box, except a dark matter planet is something that I don't think mainstream astronomy things could exist, so that might not be the exact answer. Yes, very good, Thank you, Rich. This is Space Nuts Andrew Dunkley here with Professor Fred Let's take a little break from the show to tell you about our sponsor in Cogny. Now, if you use the Internet, chances are you've registered your name, your address, your phone number, your credit card details on one or more or many websites. Occasionally, those websites will get infiltrated and that data gets sold on the dark web, and there was a case recently where thirteen million people most likely had their medical data sold through the dark web. Thirteen million. Now what happens to that data, Well, it could be just about anything. Data is available commodity the days. It's used to create fake IDs, it's used to enable people to make spam email, spam phone calls, and spam emails. It can lead to you being scammed. There was a famous case only recently where somebody got a call from their bank and it was so convincing they gave them information which led to them losing tens of thousands of dollars and the bank won't pay up because they voluntarily gave the information out. It's a very nasty case, but this is what happens. So what do you do about it? Well, you can go in and clean it. Up yourself, but as fast as you do it, some other organization or individual has already taken your data and sold it again. It's estimated would take you probably two years to wipe the Internet of all your personal information if you went it alone, if you knew how to, so probably better to get someone to do it for you. The solution is simple. You sign up to in Cogni and they. Will do all the hard work for you. They'll clear all your personal data from the world wide web and they'll keep they'll keep cleaning it up in an ongoing fashion. All you have to do is sign up, fill out a bit of background information, give them permission to work on your behalf, and then you just go from there. And it's it's simple, it's inexpensive, and it gives you peace of mind knowing that your personal information cannot be corrupted or stolen or sold on the web through in Cogny. So how do you do this? Well, as a space nuts listener, you get a special deal. Just go to incogni dot com slash space nuts. That's in Cogni dot com slash space nuts. There is a special deal on at the moment sixty percent discount and that will enable Incogny on your behalf to limit public access to your private info and reduce that risk of identity theft significantly and keep your data from being sold. And that's what it's all about. There are several options in terms of subscriptions as an individual, or you can do it as a family and friends plan. Each plan varies in price, but if you pay for an annual plan up front, it really drops the price significantly over the course of a year. But if you want to pay month by month. You can do that too, and don't forget comes with a thirty day money back guarantee. A thirty day money back guarantee. All you have to do is log in, create an account, and sign up for whatever deal suits you at incognity dot com slash space nuts and don't forget the coupon word space nuts. Surprisingly, so that's in cogniti dot com slash space nuts and the coupon code space nuts. Now back to the show. Okay, we take yourself space nuts. Our next question comes from Sean. There seems to be controversy surrounding the James Webspace telescopes pictures of galaxies in the early universe, and how many of them seem to be too big and well formed when they're only half a billion or less years old. I was pondering this question over coffee this morning people tend to do that, and was wondering if time dilation might have anything to do with this. It seems to me that if the early universe was expanding at anywhere near light speed from our point of observation thirteen point eight billion years in the future, things wouldn't be what they seem. You guys are the best. I hope this question can provide a few moments. Of filler for your awesome podcast. Sean from British Columbia. Sure you you you underestimate yourself as far more than filler. This is interesting stuff, this questions of fillers. Yeah so yeah, I mean time dilation is an interesting aspect of our view of cosmology. I don't think it solves the problem in this case, but partly because what you're talking about, Sean, here is relativistic time dilation from special relativity. You're talking about it from the point of view of things moving at near relativistic speeds, in other words, near the speed of light. And yes, you're right that the early universe expanded, probably faster than the speed of light, but only for about tenth of minus thirty three of a second. So this was way way before the origin of galaxies, way way before the origin of well matter actually, because it was just pure energy at that stage, and since then the exper has been much more sedate. So the speeds involved are not such as to I hope I'm saying the right thing here to be relativistically significant. In other words, they wouldn't cause time dilation of the kind that you're thinking of. In other words, the idea that we're seeing we're looking back our look back time is illusory. That's the point that I think you're making that we think we're looking back in time to a time, you know, when the universe was only half a billion years old, but we're not. We're actually that's an illusion. We're looking back to a time later than that, and I don't think it works in that situation. It's a nice thought. Time dilation is always good to think about because it's such a boogie phenomenon, but I don't think it works in this case, so far more than a filler shown. Great question, Thank you very much. Indeed, thanks Sean. And a question from Jane. How many stars in the humanly observable universe are already dead? Yes, well that the slow I can't give an answer to this, but I can laffle on about it. Sorry, the rapid the brief lifetimes of very massive stars, they are only ten million years or less. For you know, a very massive star such as we think were created in the early universe. These are you know, lift fast, die young stars. They're what makes the spiral arms of galaxies look blue. These are young stars, massive stars that aren't going to last very long. They'll detonate with a super and ova, possibly forming a black hole very quickly. So there's lots of these stars that are already dead because they're now something else. The most numerous stars are in the vicinity of the Sun in our own galaxy are red dwarf stars, and they're very old, and they'll go on being very old because they they're the opposite of these you know, live fast, die young, right, super massive stars. They're low mass, they churn through their hydrogen fuel very slowly and last for billions of years, outlasting the son. The Sun's got a lifetime of about ten billion years. These red dwarfs have going much longer than that. So there's a lot of the stars that aren't dead yet. But at the same time, there are a lot of stars that are that they're dead too. So, Jane, I can't give you an answer to that question directly, but to say that, yes, there is a popular of objects in the universe that are no longer visible because they've turned into something else, either a black hole or a white dwarf, as a sun like star would turn into. It's one that I'll think about again a bit more. I'm not going to call it homework because I might forget, but I'll think about that a bit more and see if we can come up with a number. How many stars in the humanly observable universe are already dead? Have to be in the billions? Well they well, oh yeah, absolutely so. How many stars are there in the universe? About ten to twenty three, because there's something like ten to the eleven stars in a galaxy, and there's about ten to the twelve galaxies in the universe, So that makes ten to the twenty three stars. And there stars like those in our own galaxy, but that doesn't count for the ones that might have already popped off a superner, so it would be it would be billions. It might actually be more than billions. It's a lot. A lot is a technical answer. Is a lot a lot. Thank you, Jane. Lovely to hear from you, and nice to get a question from our female audience sector. That's very official. It's the only way I say it these days. Andrew, Yeah, try to be careful. Finally, we're going to revisit a question we've had before. This is from Anthony and the reason we're doing it again. Fred likes Anthony's accent. I'm not kidding, that's the truth. Hi, guys, Anthony here from Kenny in Irelands. I've been looking at absolute zero being minus two hundred and seventy degrees census and if it's an absolute zero, surely there must be an absolute high temperature. Could you tell me what that is? Thank you be sure to sure. I've just realized what a great what a great accent, isn't it lovely? Yeah? So sorry, Anthony, Anthony going back to Sean because that's a very Irish name. Anthony's from kirl Kenny. Here's a weird thing, Andrew, A little weird coincidence. The friend of mine that I mentioned who was reading reading Dune back in nineteen sixty seven, Yep, his name is David Kilkenny. Yeah, there you go. I think, look there just just a little strange coincidence. Dave doesn't I'm sure Dave doesn't listen to the space nuts. But if you do, Dave, how are you doing time? You wrote to me again. He lives in Captown in South Africa. When I came to Australia to make my career back in the day he went to South Africa to make his career. He's another coincidence, right, yeah, quite a shocking one. I don't know if you've heard of the cartoon series called South Park. Yes, in every episode they kill Kenny. Oh there you go. There. You don't know where this is going to go to. But let's go to the question what's the absolute maximum? Now we did have this before, and we did answer it. Not if I recall correctly, the answer is there isn't one. Is that what happens? It is? That's correct. So absolute zero's defined. So temperature is the effect of particles moving in a solid. They just vibrate. So you know the fact that my desk is getting a bit warm because the heat is pointing at It means that the atoms in the desk top are vibrating in a In a liquid day, they swirl around in a gas, they zoom about all over the place. The temperature is related to motion, and the absolute zero is defined basically as the temperature at which all motion stops. So there isn't an absolute maximum because things can move as fast as you want them to, especially in the rarefied gas between the stars and planets. But absolute zero is well defined. It's the temperature which atomic motion stops. And as Anthony said, minus two hundred, two hundred and seventy three degrees minus two hundred and seventy three degrees celsius. That's cool. It's been like that here lately though. Yeah, all motions stopped. In my case, all motion stopped. That's run it well, especially on the golf course. Gosh, it's been a bitterly cold out there. We must be idiots, and most golfers are golfers and fishermen. Yeah, go out and all sorts of weather, so there is no absolute maximum antony is what we took a long time to say. But thanks for the question and love the accent. That's just about it, and forget. If you've got questions for us, you can send them through for our Q and A episodes via our website, space nuts podcast dot com or space nuts dot io. If you click on the little AMA button up the top, it'll give you at an interface to send us text questions or you can send an audio question. But on the right hand side of the homepage send us your questions. Press that and you can send us an audio question. Don't forget to tell us who you are and where you're from. Fred, thank you so much. It's been a great pleasure as always, good to chat Andrew. But I still wander how we got away with it to be eldest, but. Well we'll keep trying to get away with it, see what happens. Thanks Red soon, cheers, bye bye. Fred Watson, astronomer at large, part of the team here at Space Nuts. And thanks to Hu in the studio who turned up for two episodes this week, which is good because we had two episodes. And from me Andrew Dunkley, thanks for your company. As always, we'll see you on the next episode of Space Nuts. Bye bye. You'll be listening to the Space Nuts podcast. Available at Apple Podcasts, Spotify, iHeartRadio, or your favorite podcast player. You can also stream on demand at bites dot com. This has been another quality podcast production from nights dot Com.