WEBVTT 1 00:00:00.160 --> 00:00:02.640 Hi there, thanks for joining us. This is Space Nuts 2 00:00:02.759 --> 00:00:06.599 Q and A where we answer audience questions, and on 3 00:00:06.639 --> 00:00:09.919 this episode we're going to be talking about the relationship 4 00:00:09.960 --> 00:00:15.199 between dark matter and the cosmic web. We'll also look 5 00:00:15.240 --> 00:00:19.160 at an issue that's been raised about the synchronization of 6 00:00:19.559 --> 00:00:24.320 communication between Earth and long distance spacecraft. How do they 7 00:00:24.399 --> 00:00:27.359 do that because they're moving at rat of knots at 8 00:00:27.359 --> 00:00:29.960 great distances away from us, so how do we talk 9 00:00:30.000 --> 00:00:32.719 to them. There's also questions about whether or not there's 10 00:00:32.759 --> 00:00:36.719 more than one asteroid belt and can we build a 11 00:00:36.759 --> 00:00:41.479 space wheel. We'll tackle all that today on Space. 12 00:00:41.200 --> 00:00:47.640 Nuts fifteen seconds guidance in Channal ten nine ignition. 13 00:00:47.439 --> 00:00:55.359 Sequence Space Nuts or three two one Space Nuts. 14 00:00:55.679 --> 00:00:57.479 As when I reported Bill's. 15 00:00:57.119 --> 00:01:04.000 Good, here he is again, Fred. What's an hello? Fred? Hi, Andrew? 16 00:01:04.200 --> 00:01:05.159 How are you? 17 00:01:05.319 --> 00:01:07.079 I'm as good as the last time you saw me. 18 00:01:09.799 --> 00:01:11.239 I'm even wearing the same shirt. 19 00:01:11.319 --> 00:01:14.480 Strangely enough, it's extraordinary, isn't it, Soli? 20 00:01:14.640 --> 00:01:20.480 What a coincidence? Amazing? Are you ready to tackle some questions? 21 00:01:21.599 --> 00:01:22.000 Why not? 22 00:01:22.719 --> 00:01:25.280 All right, let's get down to it now. Our first 23 00:01:25.359 --> 00:01:31.400 question or questions come from the same source, and it's 24 00:01:31.480 --> 00:01:37.519 Ben and he's got a couple of interesting ideas. He says, Hi, 25 00:01:37.560 --> 00:01:41.000 there Andrew and Fred, longtime listener, but first time questioner 26 00:01:41.000 --> 00:01:45.280 from Chicago, though originally from Australia. Just in the form 27 00:01:45.400 --> 00:01:47.760 of a text as I'm one of the lucky sods 28 00:01:48.120 --> 00:01:53.920 who's gotten COVID twice in two months and can't talk. 29 00:01:54.040 --> 00:01:58.280 I'm sure some people can appreciate that. Just have two questions, 30 00:01:58.319 --> 00:02:00.840 not related, and of course one is going to be 31 00:02:01.079 --> 00:02:05.560 about dark matter. Fred mentioned in an episode that matter 32 00:02:05.640 --> 00:02:09.120 and dark matter don't interact, and one way of seeing 33 00:02:09.520 --> 00:02:14.039 that was some galaxies have moved over time, but the 34 00:02:14.039 --> 00:02:17.000 blob of dark matter doesn't move with it, to paraphrase. 35 00:02:17.319 --> 00:02:21.280 But if that's the case, my question is, how did 36 00:02:21.400 --> 00:02:24.840 dark matter form the cosmic web pattern of the universe 37 00:02:24.879 --> 00:02:28.000 in the first place. If it doesn't move, since galaxies 38 00:02:28.039 --> 00:02:32.080 are theorized to be held together using dark matter, wouldn't 39 00:02:32.120 --> 00:02:37.240 then wouldn't then moving off the dark matter blob mean 40 00:02:37.840 --> 00:02:41.719 they would start to fly apart. That's his first question. 41 00:02:41.759 --> 00:02:44.280 We'll get to the second one after we've solved. 42 00:02:43.960 --> 00:02:49.280 That riddle thread So that the interaction there is an interaction, 43 00:02:50.080 --> 00:02:53.919 which is via gravity. The least understood of all the 44 00:02:54.120 --> 00:02:58.879 fundamental forces, and that's why you know, if you've got 45 00:02:59.439 --> 00:03:03.199 a unif some baby universe that's got this web of 46 00:03:03.520 --> 00:03:10.000 dark matter, because that dark matter has gravitational interaction, then 47 00:03:10.240 --> 00:03:12.960 it will pull the normal matter in, so you do 48 00:03:13.039 --> 00:03:15.719 get you know, the galaxies strong, all out, strong, out 49 00:03:15.719 --> 00:03:18.199 along the cosmic web, as we find today when we 50 00:03:18.240 --> 00:03:22.240 observe galaxy surveys and things of that sort. The point 51 00:03:22.400 --> 00:03:26.960 I was making about the lack of interaction of other kinds, 52 00:03:27.000 --> 00:03:29.120 in other words, that you know, they don't bounce off 53 00:03:29.240 --> 00:03:34.879 one another. Was a couple of examples where we know 54 00:03:35.479 --> 00:03:39.840 that clusters of galaxies, which are the biggest sort of 55 00:03:39.879 --> 00:03:44.960 objects in the universe, they've collided and the gas and 56 00:03:45.759 --> 00:03:49.360 stars in those galaxies have sort of ground to a 57 00:03:49.400 --> 00:03:52.159 hole in the pile up. So what you end up 58 00:03:52.199 --> 00:03:57.240 with is a big blob of galaxy debris, except it's 59 00:03:57.280 --> 00:03:59.680 not debry. It's much the same as it was before 60 00:03:59.719 --> 00:04:03.319 they interacting, but they're gravitationally probably pulling one of an 61 00:04:03.400 --> 00:04:03.800 apart and. 62 00:04:03.840 --> 00:04:04.479 Things like that. 63 00:04:04.680 --> 00:04:08.400 So you've got two galaxy clusters, they collide, and you 64 00:04:08.479 --> 00:04:11.680 get a smash up there, which you can identify as 65 00:04:11.719 --> 00:04:16.360 being two different galaxy clusters colliding, but the dark matter 66 00:04:16.879 --> 00:04:20.240 from each of those because each of those clusters would 67 00:04:20.240 --> 00:04:23.079 have had its own dark matter halo. The dark matter 68 00:04:23.160 --> 00:04:28.560 just carries on. It doesn't interact either apparently with itself 69 00:04:29.000 --> 00:04:32.639 or with the debris the normal matter. 70 00:04:33.759 --> 00:04:34.879 So what you've got is. 71 00:04:36.800 --> 00:04:40.399 A scenario where you've got a new cluster of galaxies 72 00:04:40.480 --> 00:04:43.600 that's been formed from the two colliding clusters, and on 73 00:04:43.639 --> 00:04:45.560 either side of it is a blob of dark matter, 74 00:04:45.759 --> 00:04:48.160 which is the dark matter from the two original clusters 75 00:04:48.160 --> 00:04:52.120 that's just carried on going because it doesn't impact the 76 00:04:52.199 --> 00:04:56.160 normal matter. It does gravitationally, so it'll tend to have 77 00:04:56.199 --> 00:04:59.439 a gravitational influence on it, but the dark matter basically 78 00:04:59.519 --> 00:05:00.680 just just carries on. 79 00:05:01.399 --> 00:05:05.759 I'm very confusing for it. I can understand why we 80 00:05:05.800 --> 00:05:08.319 get so many questions about it, because it just doesn't 81 00:05:08.600 --> 00:05:09.639 seem to make sense. 82 00:05:11.439 --> 00:05:15.079 No, So the only thing that makes sense. 83 00:05:14.920 --> 00:05:19.160 Is that the particles of dark mutter normal matter door 84 00:05:19.519 --> 00:05:22.720 sort of bounce off one another, but they do have 85 00:05:22.839 --> 00:05:24.480 a gravitaxial effect on each other. 86 00:05:24.600 --> 00:05:26.720 That's really the way to put it. 87 00:05:27.160 --> 00:05:29.519 Okay, that makes it sound a little bit more simple, 88 00:05:29.879 --> 00:05:30.399 I hope. 89 00:05:31.399 --> 00:05:31.560 Now. 90 00:05:31.560 --> 00:05:37.680 Ben's second question, which is for spacecraft Communicating with them 91 00:05:37.720 --> 00:05:40.720 takes obviously longer and longer the further they are away, 92 00:05:41.199 --> 00:05:44.079 with all the planets moving all the time along the 93 00:05:44.120 --> 00:05:49.560 gravitational along with gravitational differences, the further or even closer 94 00:05:49.600 --> 00:05:53.079 to other orbital bodies, how do we keep the spacecraft 95 00:05:53.240 --> 00:05:57.839 synced to Earth perfectly? Would we, for spacecraft very far away, 96 00:05:57.959 --> 00:06:02.759 have to pinpoint or point telescopes further ahead of where 97 00:06:03.279 --> 00:06:06.480 they will be if it takes hours for the signal, 98 00:06:07.040 --> 00:06:11.319 or if it's close to a body like the Parker 99 00:06:11.439 --> 00:06:14.800 Solar probe. Would that not mess with the signals with 100 00:06:14.959 --> 00:06:19.839 delays possible or possibly the signal bending somehow. I'm sure 101 00:06:19.839 --> 00:06:22.759 these are taken into account, but I just wonder how 102 00:06:22.959 --> 00:06:25.680 people plan for it. I know telescopes account for this 103 00:06:25.879 --> 00:06:30.319 with redshift, but I wasn't sure how two way communication 104 00:06:30.439 --> 00:06:35.800 with satellite probes works. That's a really interesting question because 105 00:06:36.079 --> 00:06:39.079 we take for granted that we can still communicate with Voyager, 106 00:06:39.439 --> 00:06:42.839 and it is way beyond anything else that we've sat 107 00:06:42.879 --> 00:06:43.519 out so far. 108 00:06:45.120 --> 00:06:47.439 Right, it's twenty two light hours away at the moment 109 00:06:47.480 --> 00:06:50.959 I remember, Yeah, So yeah, it is a good question, 110 00:06:51.040 --> 00:06:58.079 but it can all be compensated for, and in fact 111 00:06:58.120 --> 00:07:05.680 the ben mentions the signals. And there's a classic case 112 00:07:06.720 --> 00:07:09.639 of I think it was the Cassini spacecraft when it 113 00:07:09.680 --> 00:07:11.800 was on its way to Saturn. 114 00:07:11.920 --> 00:07:13.600 This is in the early two thousands. 115 00:07:14.800 --> 00:07:21.079 It was at one point behind the Sun to us, 116 00:07:21.920 --> 00:07:24.079 but we could still see the signals because they were 117 00:07:24.120 --> 00:07:28.959 being bent by the gravitational effect of the Sun, just 118 00:07:29.079 --> 00:07:33.120 like light is. You know, it's the general relativity says 119 00:07:33.120 --> 00:07:36.199 that gravity will alter the direction of a beam of 120 00:07:36.279 --> 00:07:39.120 light or a beam of radiation. Then that was one 121 00:07:39.160 --> 00:07:43.639 of the ways. Actually, the Cassini observations of signals coming 122 00:07:44.120 --> 00:07:47.240 from the you know, the spacecraft being on the backside 123 00:07:47.240 --> 00:07:49.079 of the song but still being able to see the 124 00:07:49.120 --> 00:07:53.439 signals was one of the again one of the confirmations 125 00:07:53.480 --> 00:07:59.839 of gravitational deflection of light. Once again, you know, underpinning 126 00:08:01.199 --> 00:08:05.680 relativities absolutely fundamental place, you know, understanding of the universe. 127 00:08:06.399 --> 00:08:09.040 And yes, if you if you had a spacecraft that 128 00:08:09.160 --> 00:08:13.480 was moving across our line of sight and occasionally they 129 00:08:13.480 --> 00:08:16.480 are doing because they're you know, if you've got gravitational 130 00:08:16.839 --> 00:08:20.680 sling shot maneuvers, that might well put the spacecraft on 131 00:08:20.759 --> 00:08:23.279 the trajectory that's going across our line of sight. You 132 00:08:23.319 --> 00:08:26.639 do need to aim your your radio telescope ahead of it. 133 00:08:26.680 --> 00:08:28.639 You've got to you've got to take it into account, 134 00:08:28.800 --> 00:08:33.600 and people do that and it's completely routine. So because 135 00:08:33.600 --> 00:08:36.240 we understand what the orbits are doing, it's uh, it's 136 00:08:36.240 --> 00:08:42.559 basically a routine, you know, a routine maneuver or maneuver 137 00:08:42.639 --> 00:08:45.919 of telescope operations. Probably the person to talk to you 138 00:08:45.960 --> 00:08:49.000 about this is Glenn Nagel, who looks after the Tidbin 139 00:08:49.039 --> 00:08:53.440 Miller tracking station, one of NASA's deep space tracking network, 140 00:08:53.840 --> 00:08:57.200 which is stop far from camera. I might talk to 141 00:08:57.240 --> 00:08:58.879 him about it next time, I seeing. 142 00:08:59.120 --> 00:09:01.919 Yeah, why not? So Ben was pretty spot on with 143 00:09:02.000 --> 00:09:07.120 his salrus. Ben goes on to say thank you for 144 00:09:07.200 --> 00:09:11.159 answering this rambling and for the wonderful podcast. He said, 145 00:09:11.799 --> 00:09:15.159 I also worked for the ABC in Ultimo for a while. 146 00:09:15.200 --> 00:09:18.440 That's in Sydney, so maybe we crossed paths Andrew and 147 00:09:18.519 --> 00:09:21.600 never knew it. I was in the dark corner of 148 00:09:21.639 --> 00:09:25.879 the newsroom, Ben. I never got to the newsroom much. 149 00:09:25.919 --> 00:09:28.720 I think I actually only entered the newsroom once in 150 00:09:28.759 --> 00:09:33.120 my life, and I could feel the tension the moment 151 00:09:33.200 --> 00:09:37.440 or walked in. I know they talk about the atmosphere 152 00:09:37.559 --> 00:09:45.360 of places creating certain awareness amongst humans. I've never felt 153 00:09:45.360 --> 00:09:49.440 more intimidated than the Dale walked into the ABC Radio newsroom. 154 00:09:49.919 --> 00:09:56.120 I could feel how I don't know how deep the 155 00:09:56.159 --> 00:10:02.039 place was as an observer, and that's where they make 156 00:10:02.080 --> 00:10:05.200 all the news and current affairs programs for ABC in 157 00:10:05.279 --> 00:10:10.679 New South Wales. And I yeah, look, I don't envy 158 00:10:10.720 --> 00:10:12.799 you being there. I couldn't have worked in that environment. 159 00:10:12.840 --> 00:10:15.679 It was just too much for me. I liked my 160 00:10:15.720 --> 00:10:19.440 little regional radio job out in the Sticks much more, 161 00:10:19.799 --> 00:10:23.960 much more relaxed. Thank you, Ben. Great to hear from you, 162 00:10:24.039 --> 00:10:26.519 and hope all is well in Chicago. This is Space 163 00:10:26.639 --> 00:10:35.440 Nuts with Andrew Dugley and Professor Fred Watson Space Buds. 164 00:10:35.759 --> 00:10:40.080 Let's get some audio questions sorted out. Fred, and one 165 00:10:40.120 --> 00:10:43.799 of our regular sender inters is Sandy from I'm going 166 00:10:43.879 --> 00:10:45.960 to say Melbourne. I said that last time when I 167 00:10:45.960 --> 00:10:48.639 was wrong was a Brisbane I don't know Sandy somewhere my. 168 00:10:48.759 --> 00:10:53.240 Fred, Sandy from Melbourne a game. My question today is 169 00:10:53.279 --> 00:10:58.360 about the asteroid belts between Mars and Jupiter. As I understand, 170 00:10:58.360 --> 00:11:05.200 that's where the the primary asteroid belts are now, is 171 00:11:05.200 --> 00:11:08.440 there any other asteroid belts that's past the orbit of Jupiter, 172 00:11:09.240 --> 00:11:12.960 so I'm preferring to perhaps out towards Neptune that sort 173 00:11:13.000 --> 00:11:15.120 of or. 174 00:11:15.240 --> 00:11:17.679 Uranus sort of sort of distance. 175 00:11:19.919 --> 00:11:23.399 I'm assuming the answer is known, And if the answer 176 00:11:23.440 --> 00:11:26.840 is no, how come they've sort of massed together between 177 00:11:28.320 --> 00:11:30.360 Jupteri Mars and not further out. 178 00:11:31.080 --> 00:11:34.679 Thank you, Thanks Sandy. If you've got asteroids around Uranus, 179 00:11:34.919 --> 00:11:37.519 I think you should the doctor. But they're more likely 180 00:11:37.559 --> 00:11:44.000 to be emerhoids. Sorry I couldn't help it. Yeah, yeah, 181 00:11:44.320 --> 00:11:47.320 and look, I like the question because my first thought 182 00:11:47.399 --> 00:11:50.200 is we'll hang on the asteroid belt, yes, know all 183 00:11:50.240 --> 00:11:52.440 about that. Is there another one out there? And I 184 00:11:52.559 --> 00:11:54.720 just thought, well, it's the Kuiper Belt, but is not 185 00:11:54.840 --> 00:11:59.279 the same, is it? Or is it the same? Yeah? 186 00:12:00.120 --> 00:12:00.840 Right, Andrew. 187 00:12:01.919 --> 00:12:05.000 It's true that there are other asteroid belts, and they're 188 00:12:05.120 --> 00:12:12.919 quite different in character. So Sad is right that the 189 00:12:12.919 --> 00:12:17.399 main asteroid belt is the one and the most highly populated, 190 00:12:17.600 --> 00:12:20.600 is the one that lies between the orbits of Mars 191 00:12:20.720 --> 00:12:25.480 and Jupiter, and that's been known about since the early 192 00:12:25.759 --> 00:12:29.320 nineteenth century. The first one of those series was discovered 193 00:12:29.480 --> 00:12:32.080 on the first of January eighteen hundred and one, and 194 00:12:32.159 --> 00:12:35.960 that set the pass for you know the understanding that 195 00:12:36.000 --> 00:12:40.039 there is a belt of small objects between between Mars 196 00:12:40.039 --> 00:12:42.559 and Jupiter. We used to call them minor planets. In fact, 197 00:12:42.639 --> 00:12:46.480 when my MSc thesis is called the determination of minor 198 00:12:46.480 --> 00:12:52.399 planet orbits where you go. So that's what we now 199 00:12:52.399 --> 00:12:55.559 call the main asteroid belt. Actually, Sunday is right because 200 00:12:55.879 --> 00:12:58.480 he's talked about it as being multiple belts, and in 201 00:12:58.519 --> 00:13:02.159 a way there are different families is within those asteroid belts, 202 00:13:02.480 --> 00:13:05.200 within that main asteroid belt, if I put it that way. 203 00:13:06.039 --> 00:13:08.519 We talked about some of those in the last episode 204 00:13:08.519 --> 00:13:13.360 of Space Notes. Now as regards other asteroid belts, yes 205 00:13:13.399 --> 00:13:18.799 there are, and as you said, Andrew, the Kliper Belt 206 00:13:18.840 --> 00:13:21.480 is what really comes to mind. And that's just one 207 00:13:21.519 --> 00:13:25.600 of a number of different groups of icy asteroids which 208 00:13:25.600 --> 00:13:27.559 are beyond the orbit of Neptune, which is why they 209 00:13:27.639 --> 00:13:31.159 called trans Neptunian objects. One of the bigger ones is 210 00:13:31.159 --> 00:13:34.360 called Pluto, but it is just one of the bigger ones, 211 00:13:35.840 --> 00:13:40.879 and there are different families within that group of transit 212 00:13:41.039 --> 00:13:46.480 Tunian objects. There are objects called classical Coiper belt objects. 213 00:13:46.799 --> 00:13:50.200 There are objects called resonant objects where they have a 214 00:13:50.279 --> 00:13:53.759 resonance with the orbit of Neptune. And then the most 215 00:13:53.759 --> 00:13:57.039 distant ones are called scattered disc objects. So these are 216 00:13:57.039 --> 00:14:00.200 three different groups of objects which are in that to 217 00:14:00.440 --> 00:14:05.360 asteroid belt. They have a different formation we think from 218 00:14:06.240 --> 00:14:10.159 from the inner asteroid belt, because mostly I see those 219 00:14:10.200 --> 00:14:14.519 objects as we know blue toys, and that means that 220 00:14:14.559 --> 00:14:18.360 what we're seeing is a family of objects that really 221 00:14:18.399 --> 00:14:21.879 are the remnants of the of the of the cloud 222 00:14:21.919 --> 00:14:24.799 of dust and gas from which the Solar System formed. 223 00:14:24.840 --> 00:14:28.320 It's the outer extremities, objects that have never been warmed 224 00:14:28.399 --> 00:14:31.919 up by the Sun, the star that formed in the middle, 225 00:14:32.360 --> 00:14:36.039 whereas the asteroid belt is principally rocky objects, and we 226 00:14:36.120 --> 00:14:40.480 think it's just a sort of cloud of debris that's 227 00:14:40.519 --> 00:14:43.679 been shepherd in into that particular orbit between Mars and 228 00:14:43.720 --> 00:14:49.360 Jupiter by the huge gravitational pool of Jupiter. Jupiter's gravitational 229 00:14:49.440 --> 00:14:53.039 influence is enormous on the other planets and the minor planets, 230 00:14:53.039 --> 00:14:55.840 and we think that's what it is. There's a region 231 00:14:56.080 --> 00:15:00.360 between Mars and Jupiter where debris is collected and probably 232 00:15:00.399 --> 00:15:03.360 it's still primordial damer it's the rocky material from which 233 00:15:03.360 --> 00:15:06.480 the planets were made, but it was never able to 234 00:15:06.559 --> 00:15:08.960 form a planet because it's giant right next to it, 235 00:15:09.039 --> 00:15:11.320 as gravity is kind of swishing. 236 00:15:10.960 --> 00:15:11.840 It around a lot. 237 00:15:12.840 --> 00:15:16.519 So yes, logical reasons why we understand these different sorts 238 00:15:16.519 --> 00:15:17.240 of belts. 239 00:15:17.799 --> 00:15:22.240 What about the oat cloud? Yeah, would that be an 240 00:15:22.240 --> 00:15:23.720 asteroid belt of some kind? 241 00:15:24.559 --> 00:15:26.440 I'm meant to mention the oak cloud. Thank you for 242 00:15:26.840 --> 00:15:31.279 reminding me, Andrew, that's more of a sphere of objects 243 00:15:31.360 --> 00:15:33.159 rather than the belt of objects. I mean, we think 244 00:15:33.200 --> 00:15:34.759 of a belt as being within the plane of the 245 00:15:34.759 --> 00:15:39.919 Solar System, as indeed the asteroid belt is. The Transceptunian 246 00:15:40.000 --> 00:15:42.559 objects are much more highly inclined in their own bits, 247 00:15:42.600 --> 00:15:44.840 so they're not really a belt, but they're more like 248 00:15:44.879 --> 00:15:46.960 a belt than the Oak cloud, which is thought to 249 00:15:47.039 --> 00:15:52.080 be something that surrounds the Solar system completely. And yes, 250 00:15:52.240 --> 00:15:55.639 again it's the outer edges of this blob of gas 251 00:15:55.639 --> 00:15:58.480 and dust from which the Solar System formed. So the 252 00:15:59.000 --> 00:16:01.639 oak cloud is where the bits come from, and they 253 00:16:01.639 --> 00:16:05.320 are mostly made of vice. So that's a big difference. 254 00:16:06.039 --> 00:16:08.480 Yeah, all right, So the answer to say Andy's question 255 00:16:08.679 --> 00:16:09.200 is yes. 256 00:16:09.159 --> 00:16:14.440 Ish, it's yes, and it's big time yes really because 257 00:16:14.440 --> 00:16:17.519 we've got you know, so much more that we now 258 00:16:17.600 --> 00:16:20.480 know about the Solar System, and it's various families of 259 00:16:20.759 --> 00:16:24.759 minor objects, small objects which are important to us because 260 00:16:24.799 --> 00:16:28.399 these things occasionally collide with the Earth, so that's why 261 00:16:28.399 --> 00:16:29.679 we need to know about them. 262 00:16:30.240 --> 00:16:34.679 It would it be logical to suggest that these kinds 263 00:16:34.679 --> 00:16:36.759 of belts exist in other solar systems. 264 00:16:37.360 --> 00:16:41.320 Yeah, I think so. There's the problem with trying to 265 00:16:41.320 --> 00:16:43.240 discover them is that the objects in them are so 266 00:16:43.320 --> 00:16:46.679 small that they're you know, trying to detect them from 267 00:16:47.120 --> 00:16:49.440 from the distance that we are, which is measured in 268 00:16:49.519 --> 00:16:51.759 light years rather than millions of kilometers as we are 269 00:16:51.799 --> 00:16:57.320 in the Solar system. That's a difficult task, but maybe 270 00:16:57.320 --> 00:16:59.759 one day we'll find some evidence. There is actually evidence, 271 00:16:59.759 --> 00:17:04.599 there's evidence of comic clouds. For example, around one star 272 00:17:05.319 --> 00:17:10.880 from below if I remember rightly had an object that 273 00:17:12.079 --> 00:17:14.759 was in its protoplanetary disc that's the disc of stuff 274 00:17:14.799 --> 00:17:17.720 that's got a form planets that actually broke up into 275 00:17:18.240 --> 00:17:21.039 into pieces, and it's thought to have been an asteroid collision. 276 00:17:21.640 --> 00:17:25.640 And we've also seen a very peculiar star that has 277 00:17:25.720 --> 00:17:30.319 a brightness range that changes, and the thinking is that 278 00:17:30.400 --> 00:17:33.000 we're seeing a cloud of comments passing in front of it. 279 00:17:33.519 --> 00:17:36.240 So yes, there evidence is there, right. 280 00:17:36.000 --> 00:17:39.640 Okay, thank you Sandy, Great question, and yes you were right. 281 00:17:42.200 --> 00:17:43.079 Okay, we take a. 282 00:17:45.079 --> 00:17:49.799 Space neuts. Our final question today comes from Steve. 283 00:17:50.759 --> 00:17:50.960 Hi. 284 00:17:51.079 --> 00:17:56.200 Guys, it's Steve here from Liverpool and England. Actually just 285 00:17:56.279 --> 00:18:01.839 across the river from Liverpool, so technically plastic sculpture. Just 286 00:18:01.880 --> 00:18:06.480 a question reference. Do you ever think a Von Brawn 287 00:18:06.599 --> 00:18:10.279 wheel or you know wheel space station will ever be built? 288 00:18:11.759 --> 00:18:15.160 It's within our capabilities now, I think, you know, with 289 00:18:15.279 --> 00:18:20.319 multiple launchers and modular design they could even sell different 290 00:18:20.319 --> 00:18:24.480 modules to hotels, et cetera. But do you think it'll 291 00:18:24.519 --> 00:18:28.119 ever be built? Thank you, take care and calling on 292 00:18:28.200 --> 00:18:28.559 with the show. 293 00:18:28.759 --> 00:18:31.960 Cheers, Good on your Steve. Thank you. I'll be visiting 294 00:18:32.000 --> 00:18:34.960 Liverpool sometime next year. Can't wait. 295 00:18:35.319 --> 00:18:38.079 Can't go to the Beatles experience and do its grown. 296 00:18:38.160 --> 00:18:41.160 That's exactly what I'm going to do. Yeah, I'm going 297 00:18:41.200 --> 00:18:44.720 to do the Beatles Tour. Yeah, space Wheel. The first 298 00:18:44.720 --> 00:18:47.200 time I ever became aware of space Wheel, Fred was 299 00:18:47.240 --> 00:18:48.640 when I was a kid and I used to watch 300 00:18:48.680 --> 00:18:51.519 a TV show called Space Patrol. It was one of 301 00:18:51.519 --> 00:18:59.359 those marrying it type shows. Yeah, they Captain Scarlett was 302 00:18:59.359 --> 00:19:01.720 was probaly will be the most famous of the shows. 303 00:19:02.119 --> 00:19:04.799 This one was called Space Patrol and one of the 304 00:19:04.799 --> 00:19:09.519 space ships was actually a space wheel that I don't 305 00:19:09.599 --> 00:19:13.640 remember much more about it than that. I do remember 306 00:19:13.640 --> 00:19:17.279 a strange space creature called Gabbler, and they were trying 307 00:19:17.319 --> 00:19:20.640 to teach him to say medicine, but he kept saying 308 00:19:20.680 --> 00:19:24.240 pencil instead. Look, I don't know why that's stuck in 309 00:19:24.240 --> 00:19:29.240 my head. Say pencil, Say medicine, Gabler. He'd say pencil. 310 00:19:29.319 --> 00:19:31.680 Or was it say pencil, Gabler, He'd say medicine. It was. 311 00:19:32.279 --> 00:19:37.319 It was a sweet, some weird interstellar bird. I've got 312 00:19:37.359 --> 00:19:40.359 some strange memories from my childhood, but that one sticks 313 00:19:40.359 --> 00:19:44.160 out because of the space wheel. Do you think we'll 314 00:19:44.200 --> 00:19:44.839 ever build one? 315 00:19:46.920 --> 00:19:53.920 I do, because it is, you know, the most direct 316 00:19:54.119 --> 00:19:57.000 way of trying to provide well, that's the only way 317 00:19:57.039 --> 00:20:00.119 we know of trying to provide an artificial gravity in 318 00:20:00.119 --> 00:20:02.119 a spacecraft that's away from the Earth. You've got to 319 00:20:02.160 --> 00:20:04.880 be very careful about it, though, because there are only 320 00:20:04.960 --> 00:20:08.599 certain limits between which you can build it in terms 321 00:20:08.599 --> 00:20:13.079 of diameter and how fast it rotates. What gives me 322 00:20:13.160 --> 00:20:15.640 some confidence in this is a conversation I had. It's 323 00:20:15.680 --> 00:20:18.880 quite a number of years ago now, but with the 324 00:20:19.000 --> 00:20:22.880 husband of Linda Spilker, Linda Spilker was the mission scientist 325 00:20:22.960 --> 00:20:26.480 for Cassini for the Cassini Space mission. Her husband Tom 326 00:20:26.640 --> 00:20:30.559 is the space engineer contracted to NASA. He was at 327 00:20:30.599 --> 00:20:32.839 the time, I guess it problem still is and his 328 00:20:32.880 --> 00:20:37.960 specialty is space wheels. It's all designing the possibility of 329 00:20:38.039 --> 00:20:42.720 these large rotating structures in space that will give you 330 00:20:42.799 --> 00:20:47.839 artificial gravity. I know, when I think of the future 331 00:20:47.880 --> 00:20:51.720 of humankind, I tend to think of them not as 332 00:20:52.079 --> 00:20:54.880 colonizing Mars, which I think would be a bad thing 333 00:20:54.920 --> 00:20:57.680 to do, but I think of them building megastructures in 334 00:20:57.720 --> 00:21:00.680 space which might have artificial gravity, a bit like the 335 00:21:00.720 --> 00:21:04.960 Halo world from that very well lit early game. Oh yeah, 336 00:21:05.039 --> 00:21:08.359 it was in the early years of the century. Love 337 00:21:08.640 --> 00:21:10.680 loved playing that game with the boys when they were 338 00:21:10.680 --> 00:21:12.640 at home. And of course they made it into a 339 00:21:12.640 --> 00:21:17.720 TV series, although they've got canned after two seasons, but yeah, 340 00:21:17.759 --> 00:21:20.480 it's become a huge franchise. Did you know I might 341 00:21:20.519 --> 00:21:23.000 have mentioned this before, but in Halo there was a 342 00:21:23.039 --> 00:21:24.240 Private Chips. 343 00:21:23.960 --> 00:21:29.680 Dubbo, one of the characters. Yeah, Private Chips Dubbo because 344 00:21:29.680 --> 00:21:31.400 and he had an Australian accent. 345 00:21:31.759 --> 00:21:32.799 And well there you go. 346 00:21:33.079 --> 00:21:36.319 So he appeared in the first version of the Halo 347 00:21:36.640 --> 00:21:39.720 video game, Private Chips Dubbo because I'm from Dubbo. This 348 00:21:39.759 --> 00:21:43.279 is where I am. So yeah, so somebody must have. Yeah, 349 00:21:43.440 --> 00:21:46.240 it's a great name. Love it. And he didn't get 350 00:21:46.319 --> 00:21:50.200 killed off. He wasn't he wasn't a Red Shirt. Sorry 351 00:21:50.200 --> 00:21:54.160 I'm getting I'm digressing. Space wheels, Yes, but you're right 352 00:21:54.160 --> 00:21:57.440 that was the Halo was a space wheel, a big one. 353 00:21:57.599 --> 00:21:57.799 Yeah. 354 00:21:58.119 --> 00:22:00.440 And if we could lost to the engineering to build 355 00:22:00.440 --> 00:22:02.319 something like that, I think that's a far better way 356 00:22:02.880 --> 00:22:06.519 than colonizing a lot of the world that might have, 357 00:22:07.079 --> 00:22:09.960 you know, rudimentary microscopic life on it. 358 00:22:10.599 --> 00:22:14.000 So if you build a space wheel, and as you said, 359 00:22:14.000 --> 00:22:16.680 you've got to be careful because of size and speeds 360 00:22:16.720 --> 00:22:21.119 and creating that oneergy effect, would bigger be better because 361 00:22:21.119 --> 00:22:23.920 you wouldn't have to rotate it nearly as fast or 362 00:22:24.200 --> 00:22:24.559 I don't know. 363 00:22:24.759 --> 00:22:28.240 Yeah, Yeah, it's a it's a fine line between the two. 364 00:22:28.319 --> 00:22:31.279 It's I looked at some of the work that Tom 365 00:22:31.279 --> 00:22:35.119 Spilker is done, and you know, you you've you've wanted 366 00:22:35.200 --> 00:22:40.480 big enough that it mimics gravity rather than making you 367 00:22:40.559 --> 00:22:43.559 feel sick, which is what happens with the smaller ones, 368 00:22:44.160 --> 00:22:47.279 and you know you want you want to ensure that 369 00:22:47.680 --> 00:22:50.200 if you if you drop something in this artificial gravity, 370 00:22:50.240 --> 00:22:53.240 it just goes directly downwards rather than moving sideways, which 371 00:22:53.680 --> 00:22:56.279 if it's too small and rotating too quickly, then it 372 00:22:56.319 --> 00:22:57.680 would do or moving. 373 00:22:59.119 --> 00:23:01.039 I'm just thinking all these questions as I go. But 374 00:23:01.599 --> 00:23:04.200 if you did build a space wheel in orbit around 375 00:23:04.279 --> 00:23:09.240 Earth as a hotel or whatever, a research center, probably 376 00:23:09.240 --> 00:23:11.359 both in years to come, and who knows what else, 377 00:23:11.400 --> 00:23:14.599 But would you have it pointing at Earth on its 378 00:23:14.640 --> 00:23:18.200 axis or on its wheel? Because if you if you 379 00:23:18.279 --> 00:23:23.079 had it sort of wheel up, then you'd be standing 380 00:23:24.039 --> 00:23:26.599 with your feet in proximity to Earth. But if you 381 00:23:26.599 --> 00:23:29.279 put it on its axis, you'd actually be standing sideways. 382 00:23:31.400 --> 00:23:35.240 Yes, I think what you might do both, couldn't it? 383 00:23:35.640 --> 00:23:35.839 Yeah? 384 00:23:35.920 --> 00:23:37.960 You could? I think you'd. 385 00:23:39.319 --> 00:23:44.519 You you you know, I'm guessing here that what you'd 386 00:23:44.519 --> 00:23:47.160 want to do is really aligned it up in terms 387 00:23:47.200 --> 00:23:51.440 of where the Sun is. So if you had it 388 00:23:52.200 --> 00:23:54.559 with its axis pointing towards the Earth, but in a 389 00:23:54.559 --> 00:23:58.319 geostatiary orbit, so it was going around the Earth once 390 00:23:58.359 --> 00:24:02.839 a day, that would mean that you'd sort of limit 391 00:24:02.960 --> 00:24:06.240 the twenty four hour cycle of night and day. 392 00:24:08.440 --> 00:24:10.240 In a way that you wouldn't if it was some 393 00:24:10.359 --> 00:24:10.880 other way. 394 00:24:11.279 --> 00:24:15.440 That's a good thought. Yeah, actually that's a really good thought. Yeah, 395 00:24:15.720 --> 00:24:18.960 I know, trust you to come up with a better 396 00:24:19.000 --> 00:24:23.079 idea than me. Yeah, I'm glad did that makes perfect sense? 397 00:24:23.759 --> 00:24:28.400 So the answer is yes, probably it will happen. Why 398 00:24:28.440 --> 00:24:30.599 hasn't it happened yet? I think they've been focused on 399 00:24:30.640 --> 00:24:31.279 other things for it. 400 00:24:31.480 --> 00:24:38.480 I suppose it's fairly significant engineering. You know, there was 401 00:24:38.519 --> 00:24:42.119