WEBVTT 1 00:00:00.240 --> 00:00:02.799 Hi there, it's Space Nuts yet again. How many are 2 00:00:02.839 --> 00:00:05.160 we up to now? Four one hundred and seventy four? 3 00:00:05.240 --> 00:00:07.519 My goodness, it's a Q and A edition. My name 4 00:00:07.559 --> 00:00:11.240 is Andrew Dunkley. Thanks for joining us this time. We 5 00:00:11.359 --> 00:00:15.160 are going to be answering questions about what constellations look 6 00:00:15.359 --> 00:00:19.000 like from a different point in space. If you're traveling, 7 00:00:19.199 --> 00:00:22.440 when when does it not look like your neighborhood anymore? 8 00:00:22.719 --> 00:00:25.519 It's an interesting question. We're going to talk about a 9 00:00:25.640 --> 00:00:29.320 comet that's been in the sky recently, and I've seen 10 00:00:29.359 --> 00:00:31.679 lots of happy snaps from people on the Space Nuts 11 00:00:31.719 --> 00:00:35.960 podcast group facebook page about this comet, sou Chin Shan. 12 00:00:37.000 --> 00:00:39.560 We'll also be discussing the age of the universe and 13 00:00:39.679 --> 00:00:44.039 citizens science. That's all on this edition of Space Nuts. 14 00:00:43.960 --> 00:00:50.399 Fifteen second Channel ten nine ignition sequence. 15 00:00:50.039 --> 00:00:57.359 Space Nuts NI or three two one Space Nuts. 16 00:00:57.679 --> 00:01:01.280 As can I reported, Bills goods and joining. 17 00:01:01.039 --> 00:01:04.000 Us to answer all of those questions, it is Professor 18 00:01:04.040 --> 00:01:06.280 Fred Watson. Hello Fred, Hello on. 19 00:01:06.439 --> 00:01:08.560 Duh, Nice to see you here. 20 00:01:09.000 --> 00:01:12.239 Very yes, yes, hey you been since I saw you last. 21 00:01:13.799 --> 00:01:17.359 Sitting here? Really just waiting for something to help? 22 00:01:18.079 --> 00:01:23.879 Yes, funny that funny? Shall we get stuck straight? Into it. 23 00:01:24.640 --> 00:01:26.640 We should. Yeah, my coffee is going cold, so we 24 00:01:26.680 --> 00:01:27.280 should Oh. 25 00:01:27.359 --> 00:01:31.159 Yeah, yeah, get into that. We are going to New 26 00:01:31.280 --> 00:01:34.560 York first. This is a question from Roger. 27 00:01:36.799 --> 00:01:40.959 Roger truck driver. And then I'm traveling through the around 28 00:01:41.000 --> 00:01:43.799 Back Park in Upstate New York. I got a question 29 00:01:43.920 --> 00:01:48.719 about the constellations. I'm guessing that anywhere in our solar 30 00:01:48.840 --> 00:01:52.200 system you went, they pretty much looked the same. But 31 00:01:52.519 --> 00:01:54.680 how far would you have to go before things start 32 00:01:54.760 --> 00:01:58.359 to get disoriented? We were to we were to go 33 00:01:58.519 --> 00:02:03.519 to Alpha Centaur, like four light years away, would just 34 00:02:03.599 --> 00:02:07.799 still recognize some of them? Are? Would they be completely disoriented? 35 00:02:09.280 --> 00:02:13.080 And I'm kind of thinking of like science fiction shows 36 00:02:13.439 --> 00:02:16.599 where they show the stars flying by like trees when 37 00:02:16.639 --> 00:02:19.639 you're going down the road. I'm kind of guessing it 38 00:02:19.680 --> 00:02:22.639 wouldn't look like that because of the distance between them. 39 00:02:22.919 --> 00:02:26.000 They probably look like they stayed in the same place. 40 00:02:26.240 --> 00:02:30.000 But now the question is how far can you go 41 00:02:30.120 --> 00:02:35.039 before I think, before you don't recognize the neighborhood anymore? Right, 42 00:02:35.800 --> 00:02:38.520 loving the show, guys, keep on trucking. 43 00:02:39.479 --> 00:02:43.680 There he is. Thank you, Roger. I always love that. 44 00:02:44.479 --> 00:02:47.840 I haven't heard from Roger in a wall. Yeah, that 45 00:02:48.000 --> 00:02:52.639 was an interesting analogy about driving down the highway and 46 00:02:52.719 --> 00:02:55.719 the trees fly past. They do portray space travel that 47 00:02:55.840 --> 00:02:58.800 way with the stars, but I think it would probably 48 00:02:58.879 --> 00:03:02.639 be a much more boring viewed in that in real 49 00:03:02.800 --> 00:03:05.840 terms after a while, I mean, it'd be pretty extraordinary 50 00:03:05.879 --> 00:03:08.680 to look at, but eventually you'd be saying, oh, yeah, 51 00:03:08.719 --> 00:03:13.680 there it is, the stars still there. Yeah, and what 52 00:03:13.840 --> 00:03:15.840 check it in the thousand years time and see where 53 00:03:15.879 --> 00:03:18.319 it is. It might be a bit like that. 54 00:03:20.599 --> 00:03:23.759 It probably is actually. I mean, for first of all, 55 00:03:24.360 --> 00:03:27.919 we you know, on human timescales, with the technology that 56 00:03:28.000 --> 00:03:30.439 we have today, it takes a long time to get 57 00:03:30.719 --> 00:03:35.680 even beyond the little bit of Pluto as we know 58 00:03:35.800 --> 00:03:38.039 from New Horizons, which I think took nine years to 59 00:03:38.120 --> 00:03:42.000 get from Earth to Pluto on its epic voyage in 60 00:03:42.080 --> 00:03:47.479 the early part of this century. And it is interesting 61 00:03:47.599 --> 00:03:52.599 that that that has been used as a baseline to 62 00:03:52.919 --> 00:03:55.879 directly measure the distance to some of the stars. The 63 00:03:56.000 --> 00:03:58.759 fact that we know where star is from the Earth, 64 00:03:59.439 --> 00:04:02.280 and yeah, you get to what is it, thirty thirty 65 00:04:02.479 --> 00:04:05.719 astronomical units something like that. The distance out to Blueto 66 00:04:05.719 --> 00:04:08.719 it's thirty forty and an astronomical unit is one hundred 67 00:04:08.719 --> 00:04:11.360 and fifty million kilometers the distance from the Earth to 68 00:04:11.439 --> 00:04:16.839 the Sun. To get a view from there, their positions 69 00:04:17.560 --> 00:04:22.360 look very, very slightly different. You need to measure them 70 00:04:22.480 --> 00:04:26.600 accurately with the kind of equipment that New Horizons has 71 00:04:26.639 --> 00:04:28.600 on board. But yeah, you can see the difference there. 72 00:04:28.639 --> 00:04:30.639 You can see what we call the parallax, the distant 73 00:04:30.680 --> 00:04:35.079 the different position in the sky that a star looks 74 00:04:35.439 --> 00:04:37.959 to be from different things. Yes, in the name of 75 00:04:38.040 --> 00:04:41.319 a well known book by an author who has a 76 00:04:41.399 --> 00:04:44.079 voice very similar to the one that you're not listening 77 00:04:44.160 --> 00:04:45.639 to now, but you will be in a second. 78 00:04:46.439 --> 00:04:49.959 I think I know him. Yes, it just happened. It 79 00:04:50.040 --> 00:04:51.920 does happen to have a copy of the book on 80 00:04:52.040 --> 00:04:54.439 my desk. As you mentioned you were. 81 00:04:54.600 --> 00:04:57.079 Yeah, yeah, it's a great, great word and a great 82 00:04:57.160 --> 00:05:02.079 title from book. But you know, Roger's comments are right 83 00:05:02.160 --> 00:05:04.160 on the money. You've got to go a long way 84 00:05:04.240 --> 00:05:07.000 before the constellations start looking different. I think if you 85 00:05:07.079 --> 00:05:10.160 went to Alpha Centauri, you look at the sky and 86 00:05:10.319 --> 00:05:13.920 think that's pretty well the same sky that we see 87 00:05:14.240 --> 00:05:20.279 from except actually for except for you know, the Alpha 88 00:05:20.360 --> 00:05:23.480 Centauri itself, of the Alpha Centauri systems is a triple 89 00:05:23.600 --> 00:05:27.519 triple star system that would look pretty damn bright, and 90 00:05:27.680 --> 00:05:31.399 so you wouldn't really see the stars of Centaurus. But 91 00:05:31.720 --> 00:05:34.040 a lot of the stars in the sky are at 92 00:05:34.120 --> 00:05:37.879 distances which you measure in hundreds of light years. I 93 00:05:37.959 --> 00:05:40.560 guess with the naked eye we see out to about 94 00:05:40.839 --> 00:05:44.040 very roughly a thousand light years, and so traveling just 95 00:05:44.160 --> 00:05:47.079 for four and a bit light years is not going 96 00:05:47.160 --> 00:05:49.959 to change things that much. There'll be some constellations that 97 00:05:50.079 --> 00:05:52.160 will have the odd star looking as it's in the 98 00:05:52.199 --> 00:05:54.759 wrong place, and said Norris will be one of them, 99 00:05:54.800 --> 00:05:57.600 because you're right next to one of the stars of Centaurus. 100 00:05:58.639 --> 00:06:02.720 But I think generally speaking, you will be able to 101 00:06:02.800 --> 00:06:05.879 recognize them. They might look just slightly walked, but you're 102 00:06:05.879 --> 00:06:09.199 able to recognize them. It was certainly a common feature 103 00:06:09.959 --> 00:06:13.519 of textbooks that I used to read on astronomy when 104 00:06:13.560 --> 00:06:18.160 I was a youngster growing up and getting interested in astronomy. 105 00:06:18.319 --> 00:06:22.879 It's a common feature to have pictures of constellations as 106 00:06:22.959 --> 00:06:26.959 they are now, as they would be in ten thousand years, 107 00:06:27.160 --> 00:06:30.720 as they will be in fifty thousand years, and you know, 108 00:06:30.879 --> 00:06:32.720 and so it goes on. And that's because of the 109 00:06:32.800 --> 00:06:35.600 intrinsic motions of the stars themselves. It's not because we're 110 00:06:35.800 --> 00:06:39.399 changing our vantage point, but it was always the same. 111 00:06:39.480 --> 00:06:42.439 You could see the basic outline of a constellation and 112 00:06:42.600 --> 00:06:45.000 it would just change slightly sort of, you know, you 113 00:06:45.120 --> 00:06:47.199 realize that it's not quite the same, that something's a 114 00:06:47.240 --> 00:06:49.800 bit different about it. So I think that will be 115 00:06:50.000 --> 00:06:53.160 what you'd see as you journeyed deeper and deeper into space. 116 00:06:54.360 --> 00:06:56.879 Yeah, so you'd have to go a heck of a 117 00:06:56.959 --> 00:07:00.800 long way before yeah, really sort of went where the 118 00:07:00.839 --> 00:07:01.279 hell am I? 119 00:07:01.879 --> 00:07:02.079 Yeah? 120 00:07:02.120 --> 00:07:05.120 I think I think fifty light years a hundred light 121 00:07:05.240 --> 00:07:08.319 years you would start seeing a completely different set of 122 00:07:08.839 --> 00:07:11.839 you know, set of star patterns. You really would worry 123 00:07:12.279 --> 00:07:15.399 where you were. This would be a very alien sky 124 00:07:15.560 --> 00:07:15.800 to you. 125 00:07:17.279 --> 00:07:22.560 Yes, yes, indeed, a really interesting question. And that's brilliant 126 00:07:23.360 --> 00:07:26.279 and you know, not surprising that it's come from Roger, 127 00:07:26.319 --> 00:07:29.120 who spends a lot of time traveling and he probably 128 00:07:29.199 --> 00:07:31.319 is driving along in the trees were flashing past, and 129 00:07:31.399 --> 00:07:35.240 he went, wait a minute, yep, there's a question in that. 130 00:07:36.240 --> 00:07:37.000 So there it is. 131 00:07:38.920 --> 00:07:47.240 Thank you, Roger, Well done, Space MUDs. Our next question 132 00:07:47.519 --> 00:07:52.920 comes from Lisa. Lisa is from Prince George in British 133 00:07:52.959 --> 00:07:57.920 Columbia in Canada. Hello, Professor Fred and Andrew. I was 134 00:07:58.040 --> 00:08:02.439 lucky enough to have clear skies to comet. I'm going 135 00:08:02.480 --> 00:08:06.040 to get it right this time. Soo Chin Shan was 136 00:08:06.160 --> 00:08:09.480 passing by. He was passing by and got to observe 137 00:08:09.519 --> 00:08:11.800 it two nights in a row. I shared a few 138 00:08:11.839 --> 00:08:14.759 pictures on the Space Nuts podcast group Facebook page. If 139 00:08:14.839 --> 00:08:19.959 anyone is interested, I probably saw them, Lisa, I did too. Yeah, 140 00:08:20.360 --> 00:08:23.519 witnessing such a rare event was truly awe inspiring, and 141 00:08:23.600 --> 00:08:26.839 it got me thinking. We know this comet has an 142 00:08:26.920 --> 00:08:30.279 orbital period of eighty thousand years, but do we know 143 00:08:30.519 --> 00:08:34.200 for sure that it's been here before. Is it possible 144 00:08:34.240 --> 00:08:36.919 that it dropped out of the oort cloud more recently 145 00:08:37.200 --> 00:08:40.840 and is on its first lap, so to speak? Is 146 00:08:40.919 --> 00:08:44.279 there any way to tell other than direct observation if 147 00:08:44.320 --> 00:08:47.720 a comet is a repeat visitor. Thanks for a wonderful podcast. 148 00:08:47.759 --> 00:08:50.840 I've been listening since twenty eighteen and love of both 149 00:08:50.879 --> 00:08:55.080 the show and the community that has formed around it. Lisa, Oh, 150 00:08:55.159 --> 00:08:58.279 that's lovely, Lisa. I'm glad you're enjoying being part of 151 00:08:58.360 --> 00:09:01.320 a space nuts podcast group on Facebook. And if you're 152 00:09:01.360 --> 00:09:03.639 not yet, maybe you should go along and have a look, 153 00:09:03.639 --> 00:09:07.080 because it is a great little page. And yeah, I 154 00:09:07.120 --> 00:09:10.799 think everyone really enjoys there, their time there and their 155 00:09:10.840 --> 00:09:14.120 company and the conversation they have with each other. However, 156 00:09:14.879 --> 00:09:18.519 we have an important question to answer with Sue Chin 157 00:09:18.759 --> 00:09:21.639 Shan the comet that was in the sky recently on 158 00:09:21.759 --> 00:09:24.480 the nights I was best able to observe it. It 159 00:09:24.600 --> 00:09:27.519 was cloudy, and then when it finally cleared up, the 160 00:09:27.679 --> 00:09:29.759 darn thing was too low on the horizon for me 161 00:09:29.879 --> 00:09:32.279 to get a look at it, so I never ever 162 00:09:32.360 --> 00:09:35.639 got to see it myself, which I'm very disappointed about. 163 00:09:35.720 --> 00:09:37.919 But I'm pretty sure it won't be the last one 164 00:09:38.440 --> 00:09:41.039 to pass by in the next several years, so I 165 00:09:41.120 --> 00:09:42.440 might get a shot at another one. 166 00:09:43.799 --> 00:09:48.240 Oh you will. And I've got a similar story to you, Andrew, 167 00:09:48.559 --> 00:09:51.080 which is that when it was at its brightest in 168 00:09:51.159 --> 00:09:55.039 the evening sky here in Sydney, we had really overcust weather, 169 00:09:55.080 --> 00:09:57.480 which we've got now it's been like this for a 170 00:09:57.600 --> 00:10:02.600 month and it's not very conducive to astronomy. But I 171 00:10:02.720 --> 00:10:05.240 was lucky enough when we were I think I told 172 00:10:05.279 --> 00:10:07.840 you we were many. Now we're down at a place 173 00:10:07.879 --> 00:10:13.240 called Sea Lake near Lake Tyril in northern Victoria for 174 00:10:13.559 --> 00:10:16.600 a star fest, and there were lots of telescopes there, 175 00:10:17.159 --> 00:10:22.360 and one of them had his. One of the astronomers 176 00:10:22.440 --> 00:10:25.639 who was using these telescopes had his telescope coupled to 177 00:10:26.080 --> 00:10:30.080 a detector, a real time detector, in other words, a 178 00:10:30.159 --> 00:10:34.799 TV camera, and he was showing the results on a 179 00:10:34.840 --> 00:10:38.159 screen and he was actually pointing it at Tushin Chan 180 00:10:38.519 --> 00:10:42.600 Tu Chin Shan, and so I did see it, but 181 00:10:42.840 --> 00:10:45.519 not through the telescope, but I saw it live as 182 00:10:45.600 --> 00:10:48.559 it was on the screen. So that cheered me up 183 00:10:48.639 --> 00:10:52.639 quite a lot. Now to Lisa's question, that's a really 184 00:10:52.679 --> 00:10:57.039 good one as well. And this business of the eighty 185 00:10:57.120 --> 00:10:59.279 thousand years, it's a little bit of a moveable face 186 00:10:59.360 --> 00:11:04.320 because comment often their orbits are perturbed strongly by the 187 00:11:04.399 --> 00:11:08.519 gravity of other objects in the Solar System, including in 188 00:11:08.639 --> 00:11:13.399 particular the planet Jupiter, which is the biggest of the planets, 189 00:11:13.759 --> 00:11:17.120 and so often the orbital period of these very long 190 00:11:17.200 --> 00:11:22.679 period comets changes. Now to the nub of the question, 191 00:11:22.919 --> 00:11:26.039 could this be its first visit into the inner Solar System? 192 00:11:27.120 --> 00:11:29.879 I think it could be. I'm not sure in this case, 193 00:11:30.559 --> 00:11:33.039 and I should have read up on this, because there 194 00:11:33.120 --> 00:11:37.759 are markers in a comet's emissions when it gets near 195 00:11:37.840 --> 00:11:42.039 the Sun that give you some idea as to how 196 00:11:42.519 --> 00:11:46.000 many times it has been around the tracks, in other words, 197 00:11:46.000 --> 00:11:50.000 how many times it's passed close by the Sun, because 198 00:11:50.039 --> 00:11:52.000 it changes the structure of the comet. Every time it 199 00:11:52.080 --> 00:11:54.960 goes around the Sun. You get more of the volatiles 200 00:11:55.159 --> 00:11:59.000 blown away and you're left with a more dusty body. 201 00:11:59.279 --> 00:12:01.559 And I think think there's you know, the rate at 202 00:12:01.559 --> 00:12:05.639 which these chemicals, the elements within and molecules within the 203 00:12:05.720 --> 00:12:11.600 comets I see body, The rate at which these are 204 00:12:11.799 --> 00:12:16.799 dispersed into space changes depending on which compound you're talking about, 205 00:12:17.240 --> 00:12:20.639 And so I think by looking at the mix of 206 00:12:20.759 --> 00:12:23.480 chemicals that is being emitted by a comet when it 207 00:12:23.519 --> 00:12:25.879 gets near the Sun, you can get some idea of 208 00:12:26.000 --> 00:12:29.200 how many times it's visited the Sun. Now, I'm only 209 00:12:29.879 --> 00:12:31.840 saying things that I recall from having looked this up 210 00:12:31.879 --> 00:12:34.679 a long time ago. So there might be nuances in 211 00:12:34.840 --> 00:12:37.960 that that aren't correct, and there might also be details 212 00:12:38.039 --> 00:12:41.360 that I haven't really explained. But at the bottom line 213 00:12:41.440 --> 00:12:43.080 is that it may have been the first time around 214 00:12:43.080 --> 00:12:45.960 the Sun. If not, we might have ways of knowing 215 00:12:46.000 --> 00:12:47.559 about it, and I should check them out just to 216 00:12:47.600 --> 00:12:49.559 see what the pondits say. About that. 217 00:12:50.559 --> 00:12:56.159 Yeah, well I was only discovered last year's. 218 00:12:54.639 --> 00:12:57.600 Right it was, so it was on its incoming orbit 219 00:12:58.000 --> 00:13:00.559 last year, so we know the first thing. 220 00:13:00.679 --> 00:13:02.799 I just did a quick search. And now I've said, 221 00:13:02.960 --> 00:13:07.320 has the commet been here before? And it says it 222 00:13:07.440 --> 00:13:09.639 has never reached the inner solar system in human his 223 00:13:09.759 --> 00:13:12.440 view before? Now apparently, so there you are. So it's 224 00:13:12.519 --> 00:13:12.919 call for it. 225 00:13:13.440 --> 00:13:16.279 It's a pristine comet, isn't a thought? 226 00:13:16.960 --> 00:13:19.879 Okay, So we just have to wagit eighty thousand years 227 00:13:19.960 --> 00:13:20.919 to have another look at. 228 00:13:20.840 --> 00:13:23.159 It and see what's changed. 229 00:13:23.799 --> 00:13:27.720 Yeah, yes, indeed there's a few that are going to 230 00:13:27.759 --> 00:13:31.000 be quicker than that's that's the good news. Thank you, 231 00:13:31.080 --> 00:13:34.240 Lisa Tho. Really good question, and yeah you're right, it's 232 00:13:34.320 --> 00:13:37.879 the first time it's been here. Apparently. This is Space 233 00:13:38.000 --> 00:13:44.519 Nuts with Andrew Dunkley and Professor Fred Watson, the road. 234 00:13:45.960 --> 00:13:46.639 Piece Nuts. 235 00:13:47.159 --> 00:13:49.879 Now Fred to our next question, although we're not moving 236 00:13:50.039 --> 00:13:53.360 far around the globe because this one comes from David 237 00:13:53.399 --> 00:13:55.679 who happens to live in Canada. 238 00:13:56.240 --> 00:14:01.159 Hello Andrew and Professor Watson. David here from Saint John's 239 00:14:01.279 --> 00:14:10.480 Nufuna in Canada, just wondering how did we measure how 240 00:14:10.559 --> 00:14:13.600 old the universe is Thanks love forcast. 241 00:14:14.320 --> 00:14:18.080 Thanks David. I'm going to ask David a question that 242 00:14:18.799 --> 00:14:21.799 every time I travel and I tell people I'm Australian, 243 00:14:21.840 --> 00:14:28.039 they'll say, oh, do you know John faith Waite? Oh, David, 244 00:14:28.080 --> 00:14:34.399 do you know Lisa? Now I gather from the provinces 245 00:14:34.440 --> 00:14:36.200 they live in. They're probably not very close. 246 00:14:36.080 --> 00:14:36.720 Together at all. 247 00:14:37.480 --> 00:14:39.840 But you know, I get that. You get that a lot. 248 00:14:41.000 --> 00:14:45.600 I get that a lot when I travel. It's ridiculous. Well, 249 00:14:45.879 --> 00:14:49.600 I might know him, except there are thirty million other 250 00:14:49.679 --> 00:14:54.679 people that you know. Ah, yeah, it's funny. It is funny. 251 00:14:55.559 --> 00:14:57.919 Ah to the universe. How do we know it's right? 252 00:14:58.039 --> 00:15:00.320 How did we measure it in the first place? What's 253 00:15:00.919 --> 00:15:01.879 the goss there? 254 00:15:02.879 --> 00:15:07.480 So? Yeah, So the first measurements made of the age 255 00:15:07.519 --> 00:15:11.639 of the universe were when we started measuring what's called 256 00:15:11.639 --> 00:15:14.159 the Hubble constant, And the Hubble constant is the current 257 00:15:14.279 --> 00:15:16.559 rate of expansion of the universe. It's how fast it's 258 00:15:16.600 --> 00:15:20.480 expanding now. And it's an easy calculation to go from that. 259 00:15:21.080 --> 00:15:23.480 If you assume the expansion has been constant throughout the 260 00:15:23.559 --> 00:15:26.240 history of the universe, it's an easy calculation to go 261 00:15:26.399 --> 00:15:31.279 from the expansion velocity back to when everything was at 262 00:15:31.360 --> 00:15:35.080 the same point in space, and you get the answer. 263 00:15:35.399 --> 00:15:37.600 You get an answer of about if I remember this, 264 00:15:37.600 --> 00:15:42.360 about fifteen billion years. So that was the first way 265 00:15:42.440 --> 00:15:46.480 that we evaluated the age of the universe. And I 266 00:15:46.559 --> 00:15:50.440 guess that was in the early sixties seventies when the 267 00:15:50.480 --> 00:15:53.360 Big Bang theory was really becoming very much the theory 268 00:15:54.120 --> 00:15:58.120 of the universe as we know it rather than one 269 00:15:58.200 --> 00:16:02.720 that was just a hypothesis. And so that's the first way. 270 00:16:02.799 --> 00:16:05.679 But there are there are other ways of doing it, 271 00:16:06.200 --> 00:16:11.600 and we can you can sort of again it comes 272 00:16:11.639 --> 00:16:14.840 to it's all about accurately measuring distances and things of 273 00:16:14.919 --> 00:16:16.879 that sort, because that's what you need to do to 274 00:16:18.159 --> 00:16:19.960 get a good idea of well, first of all, the 275 00:16:20.039 --> 00:16:22.960 hubble constant. You've got to you've got to evaluate what 276 00:16:23.080 --> 00:16:26.919 that is, and it needs the measurement of distances. And 277 00:16:27.039 --> 00:16:29.759 there are two ways of measuring distances in this kind 278 00:16:29.799 --> 00:16:34.080 of context. One is standard rulers and the other is 279 00:16:34.159 --> 00:16:40.519 standard candles. So standard candle is is a light source 280 00:16:40.600 --> 00:16:43.720 that you hold up whose intrinsic brightness that you know, 281 00:16:44.799 --> 00:16:49.000 and then you see how bright it is from your 282 00:16:49.080 --> 00:16:51.399 vantage point. And if you know the intrinsic brightness, you 283 00:16:51.440 --> 00:16:54.320 can work out the distance, and that's how the super 284 00:16:54.360 --> 00:17:01.600 and ova work works. People are doing investigation of the 285 00:17:01.840 --> 00:17:04.720 in fact, in particular the dark energy and the accelerated 286 00:17:04.799 --> 00:17:07.319 expansion of the universe. They look at super and ova 287 00:17:07.720 --> 00:17:10.519 explosions of a particular type that we know has a 288 00:17:10.559 --> 00:17:15.319 certain brightness, and from that you can deduce the supernova's distance, 289 00:17:15.519 --> 00:17:18.039 and from that you can tell whether your value of 290 00:17:18.039 --> 00:17:20.400 the Hubble constant is right or whether it needs tweaking. 291 00:17:20.839 --> 00:17:24.079 And the standard ruler method actually goes back to the 292 00:17:24.160 --> 00:17:28.119 early universe when there are characteristic separations of galaxies, and 293 00:17:28.359 --> 00:17:32.079 even before that, the characteristic separation of the hot and 294 00:17:32.200 --> 00:17:35.440 cold features, of the warm and cool features in the 295 00:17:35.480 --> 00:17:40.039 cosmic microwave background radiation give you an idea about the 296 00:17:40.559 --> 00:17:43.039 you know, the age of the universe, the state of 297 00:17:43.079 --> 00:17:45.720 the universe at that time. So all these things come 298 00:17:45.759 --> 00:17:48.640 together and you've got a much more subtle value for 299 00:17:48.720 --> 00:17:50.480 the age of the universe. We now think it's thirteen 300 00:17:50.480 --> 00:17:53.720 point eight billion years, but that's not that different from 301 00:17:54.079 --> 00:17:59.400 just taking a straightforward, you know, linear expansion since zero 302 00:18:01.079 --> 00:18:04.880 to determine the age of the universe from the hob 303 00:18:05.079 --> 00:18:08.440 directly from the Hubble constant, So thirty point eight billion years. 304 00:18:08.480 --> 00:18:11.079 It's got a lot of input into it, but even 305 00:18:11.119 --> 00:18:13.240 the crudest method gives us something similar to that. 306 00:18:14.839 --> 00:18:16.920 While you were talking, I thought I'll do a Google 307 00:18:17.039 --> 00:18:21.759 search and I asked what is the exact age of 308 00:18:21.839 --> 00:18:26.880 the universe? And the answer was interesting. According to estimates, 309 00:18:26.920 --> 00:18:29.279 the universe is thirteen point seven billion years old with 310 00:18:29.359 --> 00:18:33.759 an uncertainty of two hundred million years. We can't really 311 00:18:33.839 --> 00:18:35.039 be exact, can we. 312 00:18:36.160 --> 00:18:41.759 No, that's right, so our technology has to improve. I 313 00:18:42.440 --> 00:18:48.079 have always had not a theory, but the notion that 314 00:18:48.359 --> 00:18:52.039 when we do get down to the exact age of 315 00:18:52.119 --> 00:18:55.880 the universe, it will turn out to have been created 316 00:18:56.200 --> 00:18:58.839 on the first of April, and that will tell us 317 00:18:58.920 --> 00:19:01.279 things about the universe that we probably don't really want 318 00:19:01.400 --> 00:19:01.559 to know. 319 00:19:02.119 --> 00:19:05.759 If it's just one big joke, yeah, oh, how are 320 00:19:05.799 --> 00:19:06.160 you loved? 321 00:19:07.039 --> 00:19:07.240 Yes? 322 00:19:07.440 --> 00:19:11.960 Imagine So so there it is. David several ways of 323 00:19:12.079 --> 00:19:14.359 making the measurement, and they all come up with around 324 00:19:14.400 --> 00:19:19.519 about the same number. Finally, Fred, we have a question 325 00:19:19.759 --> 00:19:24.359 from Sandy. I love these short form questions. Hi, Fred 326 00:19:24.400 --> 00:19:27.960 and Andrew, are there citizens science programs that you know 327 00:19:28.119 --> 00:19:32.559 of where average people I e. Me help with scientific 328 00:19:32.720 --> 00:19:39.720 data for asteroid occultations, occultations and light curve data submission 329 00:19:39.799 --> 00:19:43.119 for stars and asteroids. Wow, thanks Sandy. 330 00:19:45.359 --> 00:19:48.839 Yes, another great question and good on you. Some do 331 00:19:48.960 --> 00:19:52.839 that means you're making measurements, and citizens science is a 332 00:19:52.880 --> 00:19:56.039 great way of getting those measurements into our knowledge base. 333 00:19:57.599 --> 00:19:59.440 So the first thing that came into my mind was 334 00:19:59.839 --> 00:20:04.880 the universe, and Zuniverse is a kind of suite of 335 00:20:05.000 --> 00:20:09.279 citizen science programs that started, I think with the Galaxy 336 00:20:09.480 --> 00:20:14.079 Zoo project, which was citizens science citizen scientists looking at 337 00:20:14.160 --> 00:20:18.720 images from the Sloane Digital Sky Survey, and that's a 338 00:20:18.920 --> 00:20:23.599 telescope in New Mexico that surveyed the northern sky in 339 00:20:24.119 --> 00:20:27.359 very great detail. Discovered all these weird and wonderful objects, 340 00:20:28.440 --> 00:20:32.920 and they are among them galaxies, I mean, the weird 341 00:20:32.920 --> 00:20:36.000 and wonderful galaxies is probably what mostly this was about, 342 00:20:36.039 --> 00:20:40.960 hence the name Galaxy Zoo, which produced some quite extraordinary discoveries. 343 00:20:43.160 --> 00:20:45.279 Hanni's object is one that comes to mind. I think 344 00:20:45.319 --> 00:20:48.799 we might have mentioned that recently, a green blob next 345 00:20:48.839 --> 00:20:52.799 to a galaxy, which was eventually traced to gas fluorescing 346 00:20:53.359 --> 00:20:56.160 after an outburst from the center of the galaxy probably 347 00:20:56.160 --> 00:20:57.960 are burnt by the black hole at the center of 348 00:20:58.000 --> 00:21:01.400 the galaxy some millions or even billions of years ago. 349 00:21:02.200 --> 00:21:05.559 Haney's vote. It was called because I think that's the 350 00:21:06.559 --> 00:21:10.039 Dutch word for objects, and she was a Dutch school teacher, 351 00:21:10.319 --> 00:21:13.880 which probably still is. So that sort of thing was 352 00:21:13.920 --> 00:21:16.680 a particular version of cities and science, but that sort 353 00:21:16.720 --> 00:21:20.759 of spread its tentacles and became something called the zuniverse, 354 00:21:21.799 --> 00:21:24.960 which I think has a number of different projects in it, 355 00:21:25.079 --> 00:21:28.680 and I think there may well be they may well 356 00:21:28.759 --> 00:21:34.160 be asteroid occultation you know pages or like data like 357 00:21:34.240 --> 00:21:38.680 curve pages. I actually just googled cities and Science asteroid occultations. 358 00:21:39.200 --> 00:21:43.720 They came up with a number of interesting websites. Unistella 359 00:21:43.799 --> 00:21:48.480 has one Unistellar Citizen Science. Unistellar is a company that 360 00:21:49.759 --> 00:21:55.079 is actually manufactures a very particular kind of telescope, and 361 00:21:55.359 --> 00:21:59.759 they have an asteroid occultation citizen science page. That's one 362 00:21:59.799 --> 00:22:03.759 to look for. I also googled light curves, I think 363 00:22:03.839 --> 00:22:06.440 cities and science like curves. That came up with a 364 00:22:06.480 --> 00:22:11.920 whole lot of things. One of them is it's actually, 365 00:22:12.519 --> 00:22:15.480 you know, the Hubble telescope has global cities and science 366 00:22:15.559 --> 00:22:20.319 projects of its own. But zooly versus perhaps the classification 367 00:22:20.480 --> 00:22:23.720 that's biggest and perhaps most popular, and they certainly do 368 00:22:23.920 --> 00:22:30.720 have a variable star like curve citizen science project. There 369 00:22:30.799 --> 00:22:34.759 are specialist astronomical societies that do both of those things, 370 00:22:34.799 --> 00:22:40.640 as well as societies dedicated to asteroid observations and dedicated 371 00:22:40.720 --> 00:22:44.720 to variable star work. Most of them are international and 372 00:22:44.880 --> 00:22:47.039 very well established, and they're not that hard to find. 373 00:22:47.559 --> 00:22:50.279 So have a look around, Sandy, and you're sure to 374 00:22:50.359 --> 00:22:51.279 find the right one for you. 375 00:22:52.200 --> 00:22:54.759 Oh yeah, I thought I'd just throw one out there 376 00:22:54.839 --> 00:22:57.680 and say, you know, what is the greatest discovery by 377 00:22:58.079 --> 00:23:01.119 astronomical discovery by a citizen sign scientists? And it went 378 00:23:01.599 --> 00:23:05.440 straight to an August twenty twenty four article in fiz 379 00:23:05.559 --> 00:23:11.039 dot org Citizen science projects identify twenty new astronomical discoveries 380 00:23:11.039 --> 00:23:18.359 and that included previously unidentified supernovae. And there's more than 381 00:23:18.400 --> 00:23:22.079 two thousand volunteers across one hundred and five countries that 382 00:23:22.200 --> 00:23:26.039 are working on these projects. The project is called Killer 383 00:23:26.119 --> 00:23:33.759 Nova Seekers, and they're aiming to find kilo novae, the 384 00:23:33.880 --> 00:23:37.640 explo cosmic explosions of neutron stars and black holes colliding 385 00:23:37.720 --> 00:23:40.640 in distant galaxies. So there's all sorts of stuff going 386 00:23:40.680 --> 00:23:43.759 on out there. If you've search deep enough, you'll find 387 00:23:43.799 --> 00:23:46.920 what you're more in terms of citizen science in the 388 00:23:47.119 --> 00:23:50.960 realm of astronomy. So yeah, there's a lot going on. 389 00:23:51.839 --> 00:23:55.359 I don't do it with astronomy, but I do do 390 00:23:55.519 --> 00:23:58.079 a little bit of a thing that's not I don't 391 00:23:58.079 --> 00:24:00.920 suppose you call it citizens science. So I downloaded an 392 00:24:00.920 --> 00:24:06.279 app called dream Lab d am Lab, and what it 393 00:24:06.400 --> 00:24:09.119 does is at night, when I put my mobile phone 394 00:24:10.839 --> 00:24:14.240 on a charger, I open up the dream Lab app 395 00:24:14.960 --> 00:24:17.839 and I just click start session and it starts crunching 396 00:24:17.920 --> 00:24:21.680 numbers using my phone as part of a giant computer 397 00:24:22.319 --> 00:24:27.640 to sort out whatever scientific problem somebody's trying to solve. 398 00:24:27.920 --> 00:24:30.440 The last one I did, which took two years to crunch, 399 00:24:31.319 --> 00:24:37.039 was a COVID nineteen calculation. Right now, I'm doing one 400 00:24:37.119 --> 00:24:41.920 through dream Lab, supporting the Tropical cyclone Modeling Phase four study. 401 00:24:42.720 --> 00:24:48.680