#430: Dark Energy Theories & Voyager's Cosmic Rays: Your Queries Answered

Hi there. This is Space Nuts where we talk astronomy and space science. My name is Andrew Dunkley, your host. Good to have your company. This is our Q and A edition where we take audience questions and we chop them up and throw them out because we don't know the answer to anything. But we are going to attempt to discuss atmospheric tubes. Now, this is a question that Jeff's come up with. It's a sort of a what if question, so we'll look at that. Paddy is asking questions about Voyager one, which has been in the news lately. And Oliver, one of our younger listeners, is talking radiation, dark matter and dark energy. All coming up on this episode of Space Nuts fifteen seconds. Guidance is in channel ten nine ignition sequence Space Nuts or three two more red ones Space Nuts. As can I report it. Bill's good and we say hello once again to Professor Fred. What's an astronomer at La TI? Fred? Hello, Andrew, fancy seeing you here? Yes, welcome back. It's been minutes. Not even sure it was minutes. I think it might just be saying continued. Do you think this joke is getting a bit old? Now? It's pretty awful in it. But space Nuts is nol for one thing. It's its bud jokes. Terrible jokes. Horrible jokes. Yes, we'll keep them coming too. Shall we get straight into it? No, let's let true. Well yeah, okay, fair enough. What I do love about space Nuts is we've got people listening all over the world, lots of questions coming from different parts of the planet. But we do have a young audience too, which I think is one of the great things about it, having young people having such an interest in astronomy and space science. One of those people is Oliver, and Oliver's got a well a pretty curly one, but he's got his own ideas on this as well. Let's see what he's on about. Yeah. Hello, I am Oliver from Queensland. I was just wondering a pretty interesting question. So you know that a black hole creates radiation, How can it doesn't get immediately softened? Does that mean the radiation has to go faster than the speed of light? But what if it's just going a bit faster? But what if black holes that could create dark energy that would actually solve a lot of things white it And if dark energy, what if that combines with matter particles and that creates dark matter. I think that would make a lot of scent. And with little things that can go fast, it goes over there and makes the border of the universe grow even faster and faster. And when it grows faster and faster, the reason it guru's faster and faster. I know, I'm saying faster and faster a lot back. What if it goes faster and faster because there's more space for the radiation to not collide with other minor particles, so it can go to the border of the universe quicker. So we can't tell because it's there because it's going so fast. Our telescopes, like the Hubble space telescope can't see it because it's going faster than the speed of light. It's just a quick question. Thanks, love the show, Goodbye. Please tell me a good answer. No, I don't really care as long as it gets solved there. I love that ending, Oliver. That's brilliant. Gosh, what a there's a lot in there that we've got to unpack. The first part was about radiation. How come radiation from a black hole doesn't get sucked straight back in? That's a good question. It's a great question and more, you know, thank you again, Oliver for getting in touch with us and for bringing a breath the fresh air to questions. It's great to have your I just I'm revved up by his excitement, you know too, I really am me too. So we think that hawking radiation, or the radiation that's emitted from black holes, doesn't come from the black hole itself. It actually comes at the event horizon. So the event horizon is that sphere. It's an imaginary sphere around the black hole, but it's the point where there's the black hole's gravitational attraction stops any light emanating from the black hole. So outside the black hole, light can travel around inside the black hole, it can't because it just gets pulled back in. Sorry, outside the event horizon, light can travel around inside the event horizon, it just gets pulled back in. And we think hawking radiation, well, it seems to be the case that it's formed by what we call virtual party FLEs articles basically coming into being and disappearing again. And they come into being in pairs. And if one of the pair is inside the event horizon and the other one isn't, then the one that's outside the event horizon gets away and can travel because it's not within the region where the speed of light isn't enough to get away from the black hole. I hope that makes sense. But that's why the hawking radiation doesn't just get pulled back in. And it is electro excuse me, it is electromagnetic radiation. It is a mixture of the different wavelengths. It's probably pretty low energy, and we have never detected it, but the theoretical basis is sound enough that we are pretty sure that it exists. Okay, And what leads, by the way to the evaporation of black holes. It's an energy loss from black holes that over billions, many billions, perhaps tens of billions of years, the black hole will evaporate and disappear. Thankfully. Sorry, So that's one part of his question. Yes, he goes on to ask about a black hole being the reason the dark energies. Now, there are some theories and studies going on that suggests this. That's right, We've covered that, and I keep meaning to re look at that paper just to work out what the mechanism is. But there is certainly a view, if I remember rightly, was it Japanese scientists who postulated this. I can't remember. We should look back at it and perhaps do it in a bit more detail sometime. But yes, there was this view that perhaps phenomena taking place within black holes are what lead to the dark energy of the universe. The only issue with that that comes to my mind is that we we equate, we believe, and the evidence seems to be that the dark energy of the universe is totally uniform, that it's the same everywhere, And if it was something to do with black calls, you might think it will be a bit bomp it where, you know, the more black holes you've got in one part of space, the more dark energy you've got. But that doesn't seem to be the case. So I do need to look at that again. Andrew, Okay, yeah, but see that there in lies the problem with dark energy. We keep coming up with new theories, new ideas, new problems associated with those new theories and new ideas, and it just keeps going around and around and around. In our last episode was the question came up as to how the galaxies and galaxy clusters can possibly exist as they are if there isn't a dark matter halo big enough to cover it, so we've got our thinking wrong. Well, yeah, I don't know. And then Oliver goes on to ask if dark energy could, as it moves through the the universe, affect particles and become dark matter. Could they be a relationship between the two even though by name they're not actually very accurate or are well their names they're both called dark something, and that's probably where the similarity ends. Very different in their nature. And yes, it's a good point. We Oliver talked about, you know, there being more space in the universe as a dark energy makes it expand things can travel to the boundary of the universe more rapidly. We don't actually know if the universe has a boundary or not. We suspect it may not have. It may be infinite. The boundary that we can see as a horizon the cosmic microwave background radiation, which is what blocks our view beyond, so that we don't see that the you know, the more distant regions of the universe. The universe might be very big, indeed that we can see might be quite small in comparison, so and faster than light travel. I mean, Einstein's theory holds true. That in space itself, nothing can move faster than light. Space itself can and probably did during the period of inflation, and it may do again if dark energy keeps on accelerating the expansion of the universe, so that one day the universe is so big that some things that emit light it never gets here because that those that have been carried away faster than the speed of light by the space itself, but not the light moving through it. So interesting questions there. I do like your thinking, Oliver, and I hope as time goes on we might hear from you again. Oh that would be lovely, Oliver. Thanks very much for getting in touch with us, and don't lose that youthful enthusiasm ever, because it is such a ray of light, and I really appreciate hearing from you. This is space Nuts. Andrew Dunkley here with Professor Fred Watson. Space puts Now. Fred to a text question that came in from Patty. Hi, guys, thanks for answering my last question about the end of life. I remember that one. I remember that one. Yeah, thanks Patty. So here's a more boring one or four. After Voyager one's recent drama, what is a cosmic ray and how came it affects Voyager and not computers on Earth? Did NASA have to get people out of retire out of retirement to reprogram the seventies computer? And he's made a reference to the movie The Martian where they had to do that for the path find a mission that they had to reinvent during that show. Three, how can NASA hear such a week week signal? I've seen the DSN website and the signal looks weaker than a mouse part the moon. He's got a great turn of phrase, Isn't he's a technical term? Yeah? I know. We can shout really loud to Voyager, but the return signal is so weak. For will new horizons ever overtake Voyager given it smaller and launched on a bigger rocket. I think that's more than four, but that's a full episode covered. Thanks again, guys. Paddy from rainy Northern Ireland, home of the Amar Observatory, where, at the age of eight his interest in space began. Now, granddad, so it wasn't yesterday? Yeah, great questions, budd It at Alma's a wonderful place we visited a few years ago. I know the director there very well, he's a colleague of mine from Edinburgh days and also here in Australia. He worked for many years in Australia, Michael Burton. So let's go to the beginning that you've got a list of four here. What's a cosmic ray, Well, it's high energy particle. I think they're primarily muons if I remember rightly, and we think they come from distant galaxies, that there are products of energetic, energetic events in very different galaxies, and yet they're raining down on Earth all the time. How come it affects Voyager and not computers on Earth because computers on Earth are shielded by the Earth's magnetic field and its atmosphere, and so we are not irradiated to the same extent. We do get them though. Cosmic ray events are things that we used to deal with in some of the detectors that are used. In fact, I think we spoke about this a little while ago. Maybe we didn't, can't remember, but the recent araori which we saw on Earth May the tenth, we're also visible on Mars because the subatomic particles from the Sun affected the detectors on some of the cameras. We had the same thing actually with cosmic rays, which are much more energetic than the rays that come from the sun. Back in the day when I used to build instruments, one of the problems that we had was these cosmic rays essentially creating little bright spots in the images, which you had to be careful you didn't mix up with something that you were trying to try to measure. In fact, one of them we discovered that the window of the on the front of the detector was slightly radioactive, so we were getting our own cosmic rays from that. Anyway, the bottom line is protection by the atmosphere. Didn't have to get people out of retirement to reprogram the seventies computer, or probably it happens to us a lot. Certainly the Australian Astronomical Observatory, where we used to be astronomery in charge. That's a long lived observatory, celebrates its fiftieth anniversary this year, and so the original some of the original pro programmers still around. They're retired, but they are occasionally called in when there are problems. So it almost certainly happened with NASA too. How can NASA here such a weak signal? Well, big dishes, big that's right. The darks. The Deep Space Network website will tell you that the Tidbinbiller and the Goldstone and the Madrid stations all have very big detectors, very big radio telescopes that can pick up that really weak signal. Number four of Paddy's questions, will New Horizons ever overtake Voyager giving it smaller and launched on a big rocket, And the answer is no. You can very easily find the numbers on the Events Above website. They've got a page on spacecraft leaving the Solar System and the first thing you see is that the one that's going fastest is Voyager one, at sixteen point nine to three to three kilometers per second relative to the Sun at present. New Horizons, on the other hand, thirteen point six seventy five kilometers per second, so slower and not as far away. So Voyager one is always going to be the most distant object, the most distant human made object. It will it will always have that status unless it hits something, and New Horizons don't. Well, the odds of yeah, you never know, it might hit something. My guess is it will go on forever because space is so big. Yeah, maybe it might get captured by you know, it's further down the street to the chemist, but it's that's right. Space is big. That's right. What was there? Was there another one of she's at it, Thank you buddy. Fantastic questions, but yeah, well worth asking because Voyager has been in the news because the've had some technical issues but they've they've sorted them out, so that might be where they drag back the old retired nineteen seventies computer programmers with their tape cartridges and things like that. Yeah, those are the days. Like yeah, technology is taking the fun out of everything. Back in the day of tape and vinyl. Gosh, working in radio was such a joy. These days you push a button and go to sleep for a couple of minutes. It wasn't like that back in the day. I'll tell you now when I was a lad. I'm say from my perspective, things are far far better now than they It's certainly a lot easier until something breaks. Thank you, Patty space Nuts. Now to our final question Fred, and this one comes from Jeff. It's I'm down on the UK coast. I love the podcast, by the way, boys. My question is if you have a magic pipe for arguments say the meter wide diameter this pipe is totally in this story sport, but it doesn't weigh anything. So if you extend it out, say six hundred miles out into space, would it suck the atmosphere out? I don't think it would, but be interesting nominal years anyway. Cheers, chaps, keep it up, you know, I love what if questions? Jeffs And that's a real rip up. So it's an indestructible pipe, so space junk doesn't become a factor, and it's in the atmosphere. It's on Earth, and you shove it up out through the atmosphere into space where the atmosphere is almost nil, it's obviously hollow. Does it suck out our atmosphere and kill us all? Uh? No, which is great relief to all of us. Rather so, the reason why is that the atmosphere in the tube just feels the same gravitational pull as the atmosphere everywhere else. So the pressure at the bottom of the tube is always going to be the same effectively as the atmospheric pressure. It might vary slightly if the tube is sealed so that you can't get leakage of varian at the bottom then it won't be subject to the same quite the same atmosphere pressure changes that the outer atmosphere does. But it basically is still the atmosphere and it's still bound by the gravity of the Earth. So yep, it won't. It won't leak away. So why having the effect at all? You can't even wrong, japp is down. So if you're thinking about, you know, checking that out building a tube from the Isle of White up to six hundred kilometers, don't worry. It's not going to away. It'd be a big chimney. Yeah, that would be well, yeah, but the smoke it eventually back up, wouldn't It wouldn't get out in the space. If it was a chimney, that's correct, it would do what it does on Earth. It would just continue to it would continue to rise as long as it was warm, and that it would just contribute to the general less of the atmosphere in the tube. Indeed, all right, so you were right, Jeff. You didn't even need to ask the question because you knew the answer. But that's okay. I love these types of questions, the what if questions. By the way, if you do have a question for us, don't forget to visit our website, where you can click on the amail link and send us a text or audio question, or click on the send us your Questions button on the right hand side of our homepage where you can leave an audio question. Don't forget to tell us who you are and where you're from. We really do love to know where you're at. And while you're listening to us on your preferred podcast platform, please leave a review. That'll be doing us a wonderful favor. Apparently reviews make a huge difference to the state of dark matter in the universe, or the dark matter on the Internet for that matter. Football Yeah, we love your reviews. We really appreciate them. And Fred and thanks to Jeff, Patty and Oliver for contributing today. Keep the questions coming, Fred, we're done for another day. Thank you so much. Sounds great, Andrew, and we'll touch up again soon, I hope, I hope so too. Yes, maybe today, maybe tomorrow, days, maybe next week. See then. Fred Watson astronomer at large and Hugh in the studio doing what Hugh does best, and we don't know what that is. And for me, Andrew Dunkley, thanks for your company. Catch you next time on another episode of Space Nuts. Bye Bye You'll Be The Space Nuts podcast available at Apple Podcasts, Spotify, I Heart Radio, or your favorite podcast player. You can also stream on demand at bites dot com. This has been another quality podcast production from Knights dot com.