WEBVTT 0 00:00:00.560 --> 00:00:02.400 Andrew Dunkley: Hello again and thank you for joining us. 1 00:00:02.400 --> 00:00:04.800 This is a Q and A edition of Space 2 00:00:04.880 --> 00:00:07.760 Nuts. My name is Andrew Dunkley. Thanks for 3 00:00:07.760 --> 00:00:10.600 your company. Uh, in this show we answer 4 00:00:10.600 --> 00:00:13.120 audience questions and we've got, 5 00:00:13.140 --> 00:00:16.000 uh, plenty. Today, uh, Martin 6 00:00:16.079 --> 00:00:18.880 is asking us questions about the Big Rip. 7 00:00:19.280 --> 00:00:21.920 Or is it the gnab gib. We don't know which. 8 00:00:22.440 --> 00:00:25.200 Uh, Mike is wanting to know what was 9 00:00:25.200 --> 00:00:27.320 around before the Big Bang. I think we've had 10 00:00:27.320 --> 00:00:30.180 that one before but we will revisit it. Uh, 11 00:00:30.180 --> 00:00:32.300 questions about colliding neutrons on the 12 00:00:32.300 --> 00:00:34.860 stars and sunsets on the moon. 13 00:00:35.020 --> 00:00:37.740 Ah, how, ah, beautiful. Sitting 14 00:00:37.740 --> 00:00:39.980 there looking out over the Sea of Tranquilly 15 00:00:40.540 --> 00:00:43.460 getting covered in dust a 16 00:00:43.460 --> 00:00:45.780 pina colada that you can't drink because you 17 00:00:45.780 --> 00:00:48.380 know. Never mind. 18 00:00:48.620 --> 00:00:50.580 We'll answer all of those questions on this 19 00:00:50.580 --> 00:00:53.420 episode of Space Nuts. 15 seconds. 20 00:00:53.420 --> 00:00:55.704 Professor Fred Watson: Guidance is internal. 10, 21 00:00:55.856 --> 00:00:58.700 9. Ignition sequence start. 22 00:00:58.860 --> 00:01:01.739 Space Nuts. 5, 4, 3, 2. 23 00:01:01.836 --> 00:01:04.149 1. 2, 3, 4, 5. 24 00:01:04.246 --> 00:01:04.680 Speaker C: 4321. 25 00:01:04.760 --> 00:01:07.520 Professor Fred Watson: Space nuts astronauts report it feels 26 00:01:07.520 --> 00:01:07.800 good. 27 00:01:08.760 --> 00:01:10.760 Andrew Dunkley: Joining us again to solve all of those 28 00:01:10.760 --> 00:01:12.480 riddles is Professor Fred Watson Watson, 29 00:01:12.480 --> 00:01:14.040 astronomer at large. Hello Fred Watson. 30 00:01:14.120 --> 00:01:16.760 Professor Fred Watson: Hello Andrew. Good to hear your 31 00:01:17.450 --> 00:01:20.320 uh, conjectured sunset. Uh, drinks on the Sea 32 00:01:20.320 --> 00:01:22.520 of Tranquilly. I hope I can join you for it. 33 00:01:23.880 --> 00:01:26.680 Andrew Dunkley: Even if you could suck on that straw. Uh, 34 00:01:26.680 --> 00:01:28.760 lunar regolith probably doesn't taste very 35 00:01:28.760 --> 00:01:29.160 nice. 36 00:01:30.120 --> 00:01:32.630 Professor Fred Watson: That's right, yep. 37 00:01:32.630 --> 00:01:35.430 Andrew Dunkley: But um, yes, one day someone will be sitting 38 00:01:35.430 --> 00:01:38.430 in a, um, in a building looking out over 39 00:01:38.430 --> 00:01:41.030 the lunar surface, probably, you know, 40 00:01:41.030 --> 00:01:43.590 downing a beer or who knows what, 41 00:01:44.440 --> 00:01:46.110 uh, or maybe they'll just have to suck it out 42 00:01:46.110 --> 00:01:48.710 of the, the air in front of them because of 43 00:01:48.710 --> 00:01:51.630 the gravity. Who knows? Um, shall 44 00:01:51.630 --> 00:01:53.390 we get down to business and see if we can 45 00:01:53.390 --> 00:01:54.470 solve some of this stuff? 46 00:01:54.870 --> 00:01:55.510 Professor Fred Watson: Why not? 47 00:01:56.070 --> 00:01:58.550 Andrew Dunkley: All right, our first question comes from 48 00:01:58.550 --> 00:02:01.430 Martin. Now this was a really long involved 49 00:02:01.430 --> 00:02:04.410 question and I' um, I 50 00:02:04.410 --> 00:02:07.010 hope Martin will forgive me but uh, I sent 51 00:02:07.010 --> 00:02:09.730 you the whole question but I'm just going to 52 00:02:09.730 --> 00:02:12.090 do the precede version so that we're not here 53 00:02:12.090 --> 00:02:14.250 for the next 25 minutes reading out. It's not 54 00:02:14.250 --> 00:02:16.650 that long but anyway, uh, gents, thanks so 55 00:02:16.650 --> 00:02:18.290 much for the podcast. That was the question. 56 00:02:18.930 --> 00:02:21.730 No, I have uh, some questions about the Big 57 00:02:21.730 --> 00:02:24.450 Crunch now it seems to be back in vogue. 58 00:02:24.930 --> 00:02:27.770 One, is it in fact now the favoured 59 00:02:27.770 --> 00:02:30.730 theory? And two, also if we 60 00:02:30.730 --> 00:02:33.660 do get a Gnab Gibson in a 61 00:02:33.660 --> 00:02:36.300 lot of ways it sounds like a super ultra 62 00:02:36.300 --> 00:02:39.140 hyper massive black hole with all the matter 63 00:02:39.140 --> 00:02:41.260 and energy of the universe gathering to a 64 00:02:41.260 --> 00:02:44.260 singularity. Which one is it? And 65 00:02:44.350 --> 00:02:47.060 uh, why? Uh, that's Martin from 66 00:02:47.060 --> 00:02:49.019 Melbourne of course, he goes into a lot of 67 00:02:49.019 --> 00:02:51.540 detail within his question, with 68 00:02:51.860 --> 00:02:54.380 possibilities and ideas and concepts and 69 00:02:54.380 --> 00:02:57.300 lefts and rights. But yeah, um, we have 70 00:02:57.300 --> 00:02:58.950 talked about the, um, 71 00:03:00.470 --> 00:03:03.030 the Big Crunch making a comeback. They're 72 00:03:03.030 --> 00:03:05.510 starting to. Although we are still seeing an 73 00:03:05.510 --> 00:03:07.710 expanding universe, it's just not 74 00:03:07.710 --> 00:03:10.150 accelerating like it was, I think. 75 00:03:10.800 --> 00:03:12.830 Um, so that's what's brought the Big Crunch 76 00:03:12.830 --> 00:03:14.990 concept back into vogue. But, um, 77 00:03:15.830 --> 00:03:18.830 at the moment, the Big Rip seems more logical 78 00:03:18.830 --> 00:03:19.830 given what's happening. 79 00:03:20.950 --> 00:03:22.230 Professor Fred Watson: Yes. So 80 00:03:23.830 --> 00:03:26.510 it could be neither. That's 81 00:03:26.510 --> 00:03:28.670 true. You're right. 82 00:03:29.260 --> 00:03:31.910 Um, and Martin's right that we've seen a lot 83 00:03:31.910 --> 00:03:34.790 of discussion about the 84 00:03:34.790 --> 00:03:37.470 possible reduction 85 00:03:37.550 --> 00:03:40.190 of, um, the acceleration. 86 00:03:40.510 --> 00:03:42.350 So the 87 00:03:43.070 --> 00:03:45.550 universe is expanding. We've known since 88 00:03:45.550 --> 00:03:48.190 1998 that that expansion is 89 00:03:48.190 --> 00:03:51.150 accelerating. Uh, that is the work 90 00:03:51.150 --> 00:03:53.310 that got, uh, Adam 91 00:03:53.710 --> 00:03:56.470 Reese, um, saw Perl 92 00:03:56.470 --> 00:03:59.470 Mutter and uh, Brian Schmidt, their 93 00:03:59.950 --> 00:04:02.190 Nobel Prize in 2011. 94 00:04:03.870 --> 00:04:06.270 Now, um, the recent 95 00:04:06.350 --> 00:04:08.910 evidence from the Dark Energy survey, because 96 00:04:08.910 --> 00:04:10.950 we think that's caused by dark energy. We 97 00:04:10.950 --> 00:04:12.830 think it's caused by an energy of space 98 00:04:13.390 --> 00:04:16.310 itself. That, uh, means 99 00:04:16.310 --> 00:04:18.990 that as space gets bigger, it has more 100 00:04:18.990 --> 00:04:21.230 energy. And so it gets bigger, faster. 101 00:04:21.870 --> 00:04:24.070 That's the bottom line. Now, dark energy is 102 00:04:24.070 --> 00:04:27.040 the big puzzle. Um, what is it? Uh, how does 103 00:04:27.040 --> 00:04:29.800 it behave? So the Dark Energy 104 00:04:29.880 --> 00:04:32.120 Survey, which we've talked about recently, 105 00:04:32.440 --> 00:04:35.240 it's presented some results, has 106 00:04:36.120 --> 00:04:38.390 suggested that, uh, 107 00:04:40.240 --> 00:04:40.320 um, 108 00:04:43.320 --> 00:04:45.720 the acceleration may be decreasing, 109 00:04:46.860 --> 00:04:49.320 um, but it's not by any means 110 00:04:49.640 --> 00:04:51.640 confirmed. That still, 111 00:04:53.480 --> 00:04:55.700 uh, sort of new research, 112 00:04:56.420 --> 00:04:58.500 it needs a lot of verification. 113 00:04:59.160 --> 00:05:01.980 Um, and even if that was 114 00:05:01.980 --> 00:05:04.780 verified, we'd need to know just 115 00:05:04.780 --> 00:05:07.220 by how much it is decreasing, 116 00:05:08.040 --> 00:05:11.020 uh, and what phenomena might 117 00:05:11.020 --> 00:05:13.940 lie ahead in order to predict 118 00:05:13.940 --> 00:05:16.660 a Big Crunch or a gnab gib, as 119 00:05:16.660 --> 00:05:19.520 Brian Schmidt always put it. Not a missing 120 00:05:19.520 --> 00:05:22.360 BG brother. Was that Martin? Yes, that 121 00:05:22.360 --> 00:05:24.480 was another Martin. If you said that. 122 00:05:24.480 --> 00:05:26.840 Andrew Dunkley: Yeah, Martin Berman Govine. 123 00:05:26.840 --> 00:05:29.720 Professor Fred Watson: That's the man. Yes. Um, so it's still. 124 00:05:30.440 --> 00:05:33.120 I, um, think it's still a, uh, fairly 125 00:05:33.120 --> 00:05:35.620 speculative idea. Uh, 126 00:05:36.200 --> 00:05:38.320 I think it's very speculative that we might 127 00:05:38.320 --> 00:05:41.240 end up with a Big Crunch. Uh, it's still 128 00:05:41.240 --> 00:05:43.840 speculative that the acceleration is 129 00:05:43.840 --> 00:05:46.720 decreasing. And I was looking, uh, a couple 130 00:05:46.720 --> 00:05:48.360 of days ago at another paper, 131 00:05:48.930 --> 00:05:51.720 um, actually written by, um, a 132 00:05:52.440 --> 00:05:54.760 big group of authors, including some 133 00:05:54.840 --> 00:05:57.400 luminaries from Australia. Ah, also 134 00:05:57.640 --> 00:05:59.520 Brian Schmidt and Adam Reese, who I was just 135 00:05:59.520 --> 00:06:01.920 talking about. Now, uh, they are also on this 136 00:06:01.920 --> 00:06:04.519 paper, they've done a very, very careful 137 00:06:04.519 --> 00:06:07.400 reanalysis of the data. Ah, 138 00:06:08.440 --> 00:06:11.130 that basically was, um, 139 00:06:11.560 --> 00:06:14.520 what we based the initial idea of dark 140 00:06:14.520 --> 00:06:16.560 energy on. The accelerating universe. It's 141 00:06:16.560 --> 00:06:19.540 all about supernova explosions. Um, 142 00:06:19.640 --> 00:06:22.620 because there a recent paper that 143 00:06:22.620 --> 00:06:25.620 suggested that the acceleration wasn't real, 144 00:06:26.330 --> 00:06:29.020 uh, because of phenomena to do with 145 00:06:29.020 --> 00:06:31.940 galaxies. But, um, it turns out that, 146 00:06:32.500 --> 00:06:35.380 yes, it is definitely real. 147 00:06:35.380 --> 00:06:37.940 The acceleration has been firmly confirmed. 148 00:06:38.340 --> 00:06:41.180 But what hasn't been confirmed is that 149 00:06:41.180 --> 00:06:43.820 it's decreasing. So at the moment, I think 150 00:06:43.820 --> 00:06:46.740 the Big Rip is still the likely, you know, 151 00:06:46.740 --> 00:06:49.500 the likely outcome that the universe gets so 152 00:06:49.500 --> 00:06:51.980 big that space starts tearing itself to 153 00:06:51.980 --> 00:06:54.260 pieces. I find that very hard to imagine. 154 00:06:54.500 --> 00:06:55.300 Andrew Dunkley: I do too. 155 00:06:55.960 --> 00:06:58.660 Professor Fred Watson: Um, but that seems to be the more likely 156 00:06:58.740 --> 00:07:01.580 outcome than a big crunch. Or it might just 157 00:07:01.580 --> 00:07:04.420 keep going forever. Look, we're talking 158 00:07:04.420 --> 00:07:06.500 so far into the future now. With the 159 00:07:06.500 --> 00:07:08.060 observations that we can make at the moment, 160 00:07:08.060 --> 00:07:10.100 it's very hard to make any firm predictions. 161 00:07:10.580 --> 00:07:12.420 Andrew Dunkley: You know what I can't get my head around, 162 00:07:12.420 --> 00:07:14.660 Fred Watson, is that, uh, we've got an 163 00:07:14.660 --> 00:07:17.570 expanding universe. It's expanding 164 00:07:17.570 --> 00:07:20.570 at an accelerating rate. Makes me wonder 165 00:07:20.970 --> 00:07:23.770 how much bigger it's getting every second 166 00:07:24.170 --> 00:07:26.170 because it's expanding out in all directions. 167 00:07:26.650 --> 00:07:29.570 Professor Fred Watson: It is. And actually that's a parameter that 168 00:07:29.570 --> 00:07:32.370 we don't know. Uh, um, 169 00:07:34.330 --> 00:07:37.250 well, no, that's not quite true. Um, there 170 00:07:37.250 --> 00:07:39.770 is something that we call the scale factor. 171 00:07:40.170 --> 00:07:42.410 It's just a measure of the scale of the 172 00:07:42.410 --> 00:07:44.410 universe and that's getting bigger. 173 00:07:45.170 --> 00:07:45.930 Uh, so 174 00:07:49.080 --> 00:07:51.480 you can talk about the scale factor. You can 175 00:07:51.480 --> 00:07:54.010 say that now it's, uh, 176 00:07:54.840 --> 00:07:57.480 X amount bigger than it was the day before 177 00:07:57.480 --> 00:08:00.440 yesterday. Um, but in terms 178 00:08:00.440 --> 00:08:03.040 of the physical size of the universe, we 179 00:08:03.040 --> 00:08:05.980 don't know, we don't know how big it is. Um, 180 00:08:07.780 --> 00:08:10.640 uh, we know that 181 00:08:10.640 --> 00:08:12.960 the expansion extends out to the horizon 182 00:08:12.960 --> 00:08:15.540 beyond which we can't see any further. Uh, 183 00:08:15.540 --> 00:08:17.740 but there's more universe beyond that and 184 00:08:17.740 --> 00:08:20.540 it's still expanding. So we don't know how 185 00:08:20.540 --> 00:08:22.700 far it goes on beyond that. And that means we 186 00:08:22.700 --> 00:08:24.900 don't know how big it's getting. The scale 187 00:08:24.900 --> 00:08:27.420 factor is an interesting one though. Um, and 188 00:08:27.420 --> 00:08:29.540 it's what you get from redshift. If you 189 00:08:29.540 --> 00:08:32.080 measure the redshift, ah, of a, uh, 190 00:08:32.080 --> 00:08:33.300 distant galaxy, 191 00:08:34.620 --> 00:08:37.420 um, that immediately gives 192 00:08:37.420 --> 00:08:39.940 you the geometry, gives you the scale factor 193 00:08:39.940 --> 00:08:42.500 from that redshift, uh, we call the redshift 194 00:08:42.500 --> 00:08:45.460 Z. It's a, a M measure 195 00:08:45.460 --> 00:08:48.340 of how far to the red the spectrum of a 196 00:08:48.340 --> 00:08:51.220 galaxy shifted. And the increase in scale 197 00:08:51.220 --> 00:08:53.780 factor, uh, as you look back, 198 00:08:54.260 --> 00:08:55.860 I should say the decrease as you look 199 00:08:55.860 --> 00:08:58.460 backwards, if you look out to a redshift of 200 00:08:58.460 --> 00:09:01.220 Z, the difference in scale factor 201 00:09:01.220 --> 00:09:03.420 between the universe now and the universe as 202 00:09:03.420 --> 00:09:06.260 it was then is one over one plus Z. 203 00:09:06.420 --> 00:09:09.420 It's such a simple equation. Scale factor is 204 00:09:09.420 --> 00:09:12.290 one over one plus z. Uh, that's the 205 00:09:12.290 --> 00:09:14.650 change in uh, scale factor and that's an 206 00:09:14.650 --> 00:09:17.170 absolutely rigorous geometrical equation. So 207 00:09:17.170 --> 00:09:19.850 we do know the scale factor changes but we 208 00:09:19.850 --> 00:09:21.770 don't know what it means in terms of physical 209 00:09:21.770 --> 00:09:23.370 size because we don't know how big the 210 00:09:23.370 --> 00:09:24.050 universe is. 211 00:09:24.610 --> 00:09:27.470 Andrew Dunkley: No, can't see it. Um, but uh, 212 00:09:27.470 --> 00:09:29.970 it must be a massive amount of 213 00:09:30.050 --> 00:09:31.800 inflation uh 214 00:09:32.850 --> 00:09:35.010 every second if it's accelerating outwards 215 00:09:35.010 --> 00:09:37.010 and it's already as big as it is. I mean. 216 00:09:37.010 --> 00:09:37.730 Professor Fred Watson: Yes, that's right. 217 00:09:38.290 --> 00:09:40.500 Andrew Dunkley: What's driving all this dark energy? Um, 218 00:09:41.330 --> 00:09:43.440 probably. But uh. Oh gosh, 219 00:09:44.630 --> 00:09:46.880 um, it's unthinkably huge. 220 00:09:47.520 --> 00:09:49.360 But uh. M. Martin, in answer to your 221 00:09:49.360 --> 00:09:51.960 question, uh, there isn't really a favoured 222 00:09:51.960 --> 00:09:53.920 theory, they're just theories. 223 00:09:54.320 --> 00:09:57.040 So it's um, at the moment still 224 00:09:57.040 --> 00:09:59.680 expanding. Therefore the RIP concept's 225 00:09:59.680 --> 00:10:01.640 probably more favourable than the crunch 226 00:10:01.640 --> 00:10:04.440 concept. But maybe it won't be either. It 227 00:10:04.440 --> 00:10:06.720 might just keep going forever and ever until 228 00:10:06.720 --> 00:10:09.510 we bump into something else. I don't know. I 229 00:10:09.510 --> 00:10:12.230 don't know. Maybe it'll be the Big Dint. I 230 00:10:12.230 --> 00:10:12.750 don't know. 231 00:10:14.190 --> 00:10:16.030 Professor Fred Watson: I've got one of those in my car actually. 232 00:10:16.190 --> 00:10:19.150 Andrew Dunkley: Oh, haven't we all? Um, yes, 233 00:10:19.150 --> 00:10:20.960 thanks for the question Martin. It's a, ah, 234 00:10:21.070 --> 00:10:22.750 really interesting one to speculate about. 235 00:10:23.150 --> 00:10:25.190 This is Space Nuts Andrew Dunkley with 236 00:10:25.190 --> 00:10:26.510 Professor Fred Watson Watson. 237 00:10:29.310 --> 00:10:30.510 Space Nuts. 238 00:10:30.750 --> 00:10:33.230 Our next question is an audio question from 239 00:10:33.230 --> 00:10:33.710 Mike. 240 00:10:35.490 --> 00:10:38.130 Speaker C: This is Mike, uh, from Chroma in the uk. 241 00:10:39.170 --> 00:10:41.890 Um, you had a question. 242 00:10:42.210 --> 00:10:44.690 Uh, well on the podcast I'm listening to 243 00:10:45.010 --> 00:10:47.410 the beginning of the universe as in the Big 244 00:10:47.410 --> 00:10:50.329 Bang. Um, you referred to it as 245 00:10:50.329 --> 00:10:52.370 being nothing before it. 246 00:10:53.360 --> 00:10:56.130 Um, surely from uh, 247 00:10:56.130 --> 00:10:58.970 a non science point of view it would be 248 00:10:58.970 --> 00:11:01.890 better to say there was something before 249 00:11:01.890 --> 00:11:04.530 the Big Bang but you don't know what it was. 250 00:11:05.140 --> 00:11:07.250 Um, why do you 251 00:11:08.290 --> 00:11:10.930 refer to it as nothing 252 00:11:11.410 --> 00:11:14.130 before the Big Bang? Bit of a strange 253 00:11:14.130 --> 00:11:15.730 question but I thought I'd ask. 254 00:11:16.049 --> 00:11:19.010 Andrew Dunkley: Cheers, thank you Mike. And I'm 255 00:11:19.010 --> 00:11:21.370 going to make a little correction Mike, 256 00:11:21.370 --> 00:11:24.210 because I think it's me who suggested 257 00:11:24.370 --> 00:11:26.330 that um, there was nothing and I think 258 00:11:26.330 --> 00:11:28.530 Fred Watson corrected me and said well no, we 259 00:11:28.530 --> 00:11:29.730 don't know what there was. 260 00:11:30.530 --> 00:11:32.830 Professor Fred Watson: Is that the one like that? Yeah, 261 00:11:33.390 --> 00:11:35.590 something along those lines. It's nice to 262 00:11:35.590 --> 00:11:38.120 hear from you Mike. Um, we have uh, 263 00:11:38.120 --> 00:11:40.510 Chroma here in Sydney which is just down the 264 00:11:40.510 --> 00:11:42.190 road from where I live. So 265 00:11:43.470 --> 00:11:46.470 you were right to put the words UK after or 266 00:11:46.470 --> 00:11:49.350 the letters UK after Chroma, the 267 00:11:49.350 --> 00:11:50.430 original Chroma. 268 00:11:50.990 --> 00:11:53.310 Andrew Dunkley: We've had a few of these recently with people 269 00:11:53.310 --> 00:11:56.030 from Vancouver in the United States. Where 270 00:11:56.030 --> 00:11:58.790 was the other one? Um, which 271 00:11:58.790 --> 00:12:01.310 wasn't where we'd normally think. Yeah, 272 00:12:01.310 --> 00:12:01.670 anyway. 273 00:12:01.670 --> 00:12:03.350 Professor Fred Watson: Well, yeah, it depends on your perspective, 274 00:12:03.350 --> 00:12:04.990 doesn't it? Yes, it does. If you're in 275 00:12:04.990 --> 00:12:06.390 Britain, Chrome is in the uk. 276 00:12:06.630 --> 00:12:07.110 Andrew Dunkley: Yeah. 277 00:12:07.520 --> 00:12:10.510 Professor Fred Watson: Um, so, so the, yes, 278 00:12:10.510 --> 00:12:13.310 the, I, I mean you can say there was 279 00:12:13.310 --> 00:12:15.310 nothing. Uh, look, the, the glib way of 280 00:12:15.310 --> 00:12:17.910 saying of the origin of the universe is in 281 00:12:17.910 --> 00:12:19.470 the beginning there was nothing and then it 282 00:12:19.470 --> 00:12:21.950 exploded. And that might be what Mike's 283 00:12:21.950 --> 00:12:24.630 thinking of, um, but that 284 00:12:24.870 --> 00:12:27.730 is pointing you in the wrong 285 00:12:27.730 --> 00:12:29.450 direction because 286 00:12:30.730 --> 00:12:33.210 certainly with the best of our knowledge at 287 00:12:33.210 --> 00:12:35.690 the moment, and that excludes things like 288 00:12:35.690 --> 00:12:38.570 ideas of multiverses, because we simply don't 289 00:12:38.570 --> 00:12:40.730 know whether multiverses exist or not. 290 00:12:41.290 --> 00:12:43.930 We have a universe that we know 291 00:12:44.410 --> 00:12:46.410 had a very explosive event 292 00:12:46.890 --> 00:12:49.690 13.8 billion years ago. We believe 293 00:12:49.690 --> 00:12:52.140 it was the beginning because, uh, 294 00:12:52.640 --> 00:12:55.560 the theory of relativity says that, and 295 00:12:55.560 --> 00:12:58.520 relativity, in all the tests we've thrown at 296 00:12:58.520 --> 00:13:01.480 it over the hundred odd years that 297 00:13:01.480 --> 00:13:04.480 it's been, you know, accepted, 298 00:13:05.010 --> 00:13:08.000 um, it survived all the tests with incredible 299 00:13:08.240 --> 00:13:10.680 robustness. So it's worthwhile 300 00:13:10.680 --> 00:13:13.640 believing what it tells you. And 301 00:13:13.640 --> 00:13:16.000 what it tells you is that time started 302 00:13:16.560 --> 00:13:19.040 with the Big Bang. And so, 303 00:13:19.430 --> 00:13:21.350 um, it means that 304 00:13:22.710 --> 00:13:24.790 the word before doesn't mean anything 305 00:13:25.750 --> 00:13:28.070 because there was no time. 306 00:13:28.850 --> 00:13:31.270 Um, it was Stephen Hawking who always 307 00:13:32.150 --> 00:13:34.910 drew the analogy that um, you 308 00:13:34.910 --> 00:13:37.870 know, he said when you look back in 309 00:13:37.870 --> 00:13:40.310 time it's like 310 00:13:41.130 --> 00:13:44.110 um, going along a line of longitude on 311 00:13:44.110 --> 00:13:47.030 the, ah, Earth heading, say northwards. You 312 00:13:47.030 --> 00:13:49.070 keep on going northwards. What are you doing? 313 00:13:49.070 --> 00:13:50.870 You're going northwards. You know where 314 00:13:50.870 --> 00:13:52.390 you're going, you know what direction you're 315 00:13:52.390 --> 00:13:55.190 going in. When you get to the North Pole, it 316 00:13:55.190 --> 00:13:57.870 has no more meaning because you're at the 317 00:13:57.870 --> 00:13:59.790 beginning, you're kind of at the origin of 318 00:13:59.790 --> 00:14:02.550 it. And that's the 319 00:14:03.030 --> 00:14:05.950 analogy he draws, that the Big 320 00:14:05.950 --> 00:14:08.910 Bang, um, time stops 321 00:14:08.910 --> 00:14:11.840 having any meaning. So you can't 322 00:14:11.840 --> 00:14:13.680 describe what came before because before 323 00:14:13.680 --> 00:14:14.560 doesn't exist. 324 00:14:16.480 --> 00:14:17.120 Andrew Dunkley: Okay, 325 00:14:19.680 --> 00:14:21.600 I see where he's getting frustrated though, 326 00:14:21.600 --> 00:14:21.880 because. 327 00:14:21.880 --> 00:14:24.760 Professor Fred Watson: Yeah, well, we all are. Ah, yeah. And that's 328 00:14:24.760 --> 00:14:27.360 because we think in a normal four 329 00:14:27.360 --> 00:14:30.320 dimensional world, three dimensions of space 330 00:14:30.320 --> 00:14:33.240 and one of time. And time is such a 331 00:14:33.240 --> 00:14:36.140 fundamental part of our existence, uh, 332 00:14:36.240 --> 00:14:38.960 that um, it's hard to 333 00:14:38.960 --> 00:14:41.480 imagine something without 334 00:14:41.640 --> 00:14:44.280 time. Um, the 335 00:14:44.440 --> 00:14:46.770 most recent work on this, uh, 336 00:14:47.160 --> 00:14:49.990 looks as though time is actually, ah, 337 00:14:49.990 --> 00:14:52.320 something that emerges from a much deeper 338 00:14:52.320 --> 00:14:55.200 reality. Uh, this is what the people who are 339 00:14:55.200 --> 00:14:57.600 trying to unite relativity and quantum 340 00:14:57.600 --> 00:15:00.360 mechanics say that there's a 341 00:15:00.360 --> 00:15:03.040 deeper reality and maybe time is just an 342 00:15:03.040 --> 00:15:05.920 artefact that in fact some people say 343 00:15:05.920 --> 00:15:07.840 emerges from entanglement. Quantum 344 00:15:07.840 --> 00:15:10.580 entanglement. That works. I have no idea. 345 00:15:10.580 --> 00:15:13.380 But, um, it's a possibility 346 00:15:13.620 --> 00:15:16.100 that we might understand time a bit better, 347 00:15:16.700 --> 00:15:19.580 uh, with some of the outcomes of 348 00:15:19.580 --> 00:15:22.380 some of these theories, and then you might 349 00:15:22.380 --> 00:15:25.060 be able to see. Well, yes, you're right. 350 00:15:25.060 --> 00:15:26.860 Before the Big Bang, there was no time. So 351 00:15:26.860 --> 00:15:28.500 there's no before. It doesn't exist. 352 00:15:28.980 --> 00:15:31.620 Andrew Dunkley: Yeah. And I just did a 353 00:15:32.980 --> 00:15:35.540 speculative question to Chatgpt what was 354 00:15:35.540 --> 00:15:37.980 around before the Big Bang, and it basically 355 00:15:37.980 --> 00:15:39.540 said exactly what you've just said. 356 00:15:40.020 --> 00:15:40.970 Professor Fred Watson: Glad to hear that. 357 00:15:41.120 --> 00:15:42.960 Andrew Dunkley: One of the answers is nothing. Uh, another 358 00:15:42.960 --> 00:15:45.840 one is that, um, um, something 359 00:15:45.920 --> 00:15:48.840 from nothing. A quantum origin, a, uh, 360 00:15:48.960 --> 00:15:51.840 previous universe, which is the bounce model. 361 00:15:52.120 --> 00:15:52.530 Professor Fred Watson: Ah. 362 00:15:53.040 --> 00:15:55.440 Andrew Dunkley: Eternal inflation, multiverse 363 00:15:55.840 --> 00:15:58.800 possibilities, uh, or cyclic universes. I 364 00:15:58.800 --> 00:16:00.240 don't think we've talked about that before. 365 00:16:00.600 --> 00:16:03.480 Um, and look, the 366 00:16:03.480 --> 00:16:06.240 real answer is we just don't know. 367 00:16:06.970 --> 00:16:09.810 Professor Fred Watson: No, but imagine if we could really iron out 368 00:16:09.810 --> 00:16:12.730 what time is all about, then we might have 369 00:16:12.730 --> 00:16:14.810 a bit better idea. We might have some sort of 370 00:16:15.050 --> 00:16:17.890 lever on the Big Bang. The 371 00:16:17.890 --> 00:16:19.880 only physical, um, 372 00:16:21.370 --> 00:16:24.050 we understand the Big Bang quite well in 373 00:16:24.050 --> 00:16:26.330 terms of the chemistry that it generated, 374 00:16:26.650 --> 00:16:29.530 what happened in terms of the energy creating 375 00:16:29.690 --> 00:16:32.010 atoms. That's all pretty well, 376 00:16:32.810 --> 00:16:35.550 um, understood from the particle physics 377 00:16:35.550 --> 00:16:37.790 theory. Uh, but 378 00:16:39.950 --> 00:16:42.230 when you go to the first few gazillionths of 379 00:16:42.230 --> 00:16:45.070 a second, then all these theories just break 380 00:16:45.070 --> 00:16:47.550 down and we've no idea what was going on. But 381 00:16:47.550 --> 00:16:49.390 if we could understand time a bit better, 382 00:16:49.390 --> 00:16:51.390 then that might lead us some insights. 383 00:16:51.390 --> 00:16:53.510 What I was going to say was the only real 384 00:16:53.510 --> 00:16:55.710 measurements that we can make, uh, of the 385 00:16:55.710 --> 00:16:57.870 cosmic microwave background radiation, and 386 00:16:57.870 --> 00:16:59.910 that's been very well measured to try and 387 00:16:59.910 --> 00:17:02.910 understand what the conditions were like 388 00:17:02.910 --> 00:17:05.630 in the Big Bang. Um, um, what you're seeing 389 00:17:05.950 --> 00:17:08.510 then is something that happened 380,000 years 390 00:17:08.510 --> 00:17:10.230 after the Big Bang. So you're not talking 391 00:17:10.230 --> 00:17:11.790 about the first gazillionth of a second. 392 00:17:12.190 --> 00:17:14.550 You're looking at a bright surface which 393 00:17:14.550 --> 00:17:17.030 corresponds with, uh, the time when the 394 00:17:17.030 --> 00:17:18.510 universe was glowing brightly. 395 00:17:20.270 --> 00:17:22.590 Andrew Dunkley: Yeah. My theory is that God was making 396 00:17:22.590 --> 00:17:24.670 breakfast, cracked an egg, and that some of 397 00:17:24.670 --> 00:17:27.350 the whites slid out of the side of the fry 398 00:17:27.350 --> 00:17:30.330 pan and hit the hot plate and there was a 399 00:17:30.330 --> 00:17:32.730 big bang. That's what I reckon happened. 400 00:17:33.530 --> 00:17:34.010 Professor Fred Watson: Yeah. 401 00:17:35.290 --> 00:17:37.130 Andrew Dunkley: Which also proves the theory that the egg 402 00:17:37.130 --> 00:17:37.850 came first. 403 00:17:41.530 --> 00:17:43.130 So, yeah, I solved two problems. 404 00:17:43.210 --> 00:17:46.050 Professor Fred Watson: It's two problems at once. Nobody 405 00:17:46.050 --> 00:17:48.210 can say you don't get good value for money 406 00:17:48.210 --> 00:17:50.970 from space nuts. Very true. 407 00:17:51.050 --> 00:17:53.770 Especially considering it's free. Yeah. 408 00:17:53.770 --> 00:17:54.170 Yeah. 409 00:17:55.050 --> 00:17:56.570 Andrew Dunkley: Unless you want to. But that's optional. 410 00:17:56.570 --> 00:17:57.540 Professor Fred Watson: Unless you want to. That's right. 411 00:17:57.540 --> 00:17:59.780 Andrew Dunkley: Um, but all voluntary. Mike. 412 00:18:00.740 --> 00:18:02.940 Can't answer the question, really. We, we 413 00:18:02.940 --> 00:18:05.100 don't really know what was around before the 414 00:18:05.100 --> 00:18:07.060 Big Bang. If there was anything, I think 415 00:18:07.060 --> 00:18:09.020 would be the bottom line. Thanks for the 416 00:18:09.020 --> 00:18:10.940 question. Thanks for sending it in. This is 417 00:18:10.940 --> 00:18:13.180 Space Nuts, a Q and A edition with Andrew 418 00:18:13.180 --> 00:18:15.220 Dunkley and Professor Fred Watson Watson. 419 00:18:18.100 --> 00:18:20.340 Speaker C: Three, two, one. 420 00:18:20.900 --> 00:18:23.180 Andrew Dunkley: Space Nuts Radio. 421 00:18:23.180 --> 00:18:26.020 Our next question, uh, is from Colin. When 422 00:18:26.020 --> 00:18:28.900 two neutron stars collide, do 423 00:18:28.900 --> 00:18:31.840 any FR Break off? If so, 424 00:18:31.970 --> 00:18:33.920 uh, there could be billions of such high, 425 00:18:34.160 --> 00:18:36.600 ultra high density fragments loose in the 426 00:18:36.600 --> 00:18:39.400 universe. Uh, what would an impact mean 427 00:18:39.400 --> 00:18:42.320 for a planet like Earth? Thank you, Colin. 428 00:18:42.720 --> 00:18:45.680 You make us feel very cosy and safe now, 429 00:18:46.130 --> 00:18:48.760 uh, after that one, um, I would 430 00:18:48.760 --> 00:18:50.900 imagine because neutron stars, uh, 431 00:18:51.280 --> 00:18:53.680 renowned for their intense gravity, are they 432 00:18:53.680 --> 00:18:56.480 not? Would it be more or less 433 00:18:56.480 --> 00:18:58.960 impossible for a bit to break off and fly off 434 00:18:58.960 --> 00:19:00.480 into the universe or could that happen? 435 00:19:01.210 --> 00:19:03.870 Professor Fred Watson: Yeah, um, you're right, Andrew. Um, 436 00:19:04.570 --> 00:19:06.410 they coalesce, they become 437 00:19:07.770 --> 00:19:10.410 one object, um, because of the 438 00:19:10.410 --> 00:19:12.950 extreme gravity. Uh, 439 00:19:13.090 --> 00:19:14.400 uh. And um, 440 00:19:17.290 --> 00:19:19.130 there might be fragments caused, but they'd 441 00:19:19.130 --> 00:19:22.130 instantly be sucked back into the 442 00:19:22.130 --> 00:19:24.250 neutron star. Um, I think it's probably 443 00:19:24.250 --> 00:19:26.890 better to imagine them as two blobs 444 00:19:26.970 --> 00:19:29.770 that uh, that coalesce together once they 445 00:19:29.770 --> 00:19:32.690 collide with a very considerable release of 446 00:19:32.690 --> 00:19:34.970 energy, which we see mostly as gravitational 447 00:19:34.970 --> 00:19:35.690 waves, actually. 448 00:19:36.490 --> 00:19:38.490 Andrew Dunkley: Yeah, well, we're talking ultra high 449 00:19:38.970 --> 00:19:41.610 density in a very small package, aren't we? 450 00:19:41.690 --> 00:19:44.010 Professor Fred Watson: Yes, exactly. Something the size of a city, 451 00:19:44.810 --> 00:19:46.330 uh, with a mass of a star. 452 00:19:46.650 --> 00:19:49.610 Andrew Dunkley: Yeah, um, I think Los Angeles 453 00:19:49.610 --> 00:19:52.210 is probably denser. No, I'm sorry, I couldn't 454 00:19:52.210 --> 00:19:54.540 help that. That was, you know, I'm not 455 00:19:54.540 --> 00:19:57.260 picking on Los Angeles. In fact, I probably 456 00:19:57.260 --> 00:19:59.140 picked a bad target because that's a lot of 457 00:19:59.140 --> 00:20:00.860 people that would be very angry with me right 458 00:20:00.860 --> 00:20:01.060 now. 459 00:20:01.060 --> 00:20:03.860 Professor Fred Watson: But anyway, we just lost half our audience. 460 00:20:03.860 --> 00:20:06.500 Andrew Dunkley: Yes, I think we did. Um, but 461 00:20:06.580 --> 00:20:09.140 no, um, they've got to understand my sense of 462 00:20:09.140 --> 00:20:10.980 humour. But nobody does understand it. 463 00:20:12.180 --> 00:20:13.060 Professor Fred Watson: Not even you. 464 00:20:13.220 --> 00:20:14.100 Andrew Dunkley: Not even me. 465 00:20:14.660 --> 00:20:17.460 But we're talking a 466 00:20:18.340 --> 00:20:21.240 really interesting object in space too. Um, 467 00:20:21.240 --> 00:20:23.860 neutron stars are, ah. Um. 468 00:20:24.100 --> 00:20:26.960 One of the storeys we did not was a while ago 469 00:20:26.960 --> 00:20:29.280 now was about the mountain ranges on neutron 470 00:20:29.280 --> 00:20:32.000 stars. You know, the highest peaks are like a 471 00:20:32.000 --> 00:20:33.760 few millimetres high or something. 472 00:20:33.920 --> 00:20:34.800 Professor Fred Watson: Yes, they were. 473 00:20:35.040 --> 00:20:36.880 Andrew Dunkley: It's very, very weird place. 474 00:20:37.040 --> 00:20:38.320 Professor Fred Watson: Yeah, yeah. 475 00:20:38.750 --> 00:20:41.360 Andrew Dunkley: Um, do we know how they're formed initially? 476 00:20:42.080 --> 00:20:44.550 Professor Fred Watson: Yeah, yeah. By gravitational collapse at uh, 477 00:20:44.600 --> 00:20:46.200 the end of a star's life when. 478 00:20:46.200 --> 00:20:49.160 Andrew Dunkley: So what class of star would have existed to 479 00:20:49.160 --> 00:20:50.400 create a neutron star? 480 00:20:50.560 --> 00:20:51.280 Professor Fred Watson: Big ones. 481 00:20:52.130 --> 00:20:53.970 Andrew Dunkley: Big sort of super blue giant. 482 00:20:53.990 --> 00:20:56.730 Professor Fred Watson: Um, yeah, that's right. That's exactly 483 00:20:56.730 --> 00:20:58.690 right. So, um, stars with a mass, 484 00:21:01.490 --> 00:21:03.490 I think it's two to 485 00:21:04.130 --> 00:21:06.570 sort of. Two to Five times the mass of the 486 00:21:06.570 --> 00:21:09.570 sun or something like that. It um, might be a 487 00:21:09.570 --> 00:21:11.850 bit bigger. Uh, ten times the mass of the sun 488 00:21:11.850 --> 00:21:14.330 gives you a black hole basically. So 489 00:21:14.330 --> 00:21:17.290 somewhere below that but in the upper reaches 490 00:21:17.290 --> 00:21:19.890 will give you a neutron star collapse. 491 00:21:20.370 --> 00:21:22.930 Andrew Dunkley: Okay, so, okay, so 492 00:21:23.250 --> 00:21:25.810 our star won't do that. It's not big enough 493 00:21:25.810 --> 00:21:27.890 to do anything. It's just going to, you know, 494 00:21:27.890 --> 00:21:30.330 retire and find itself a street corner with 495 00:21:30.330 --> 00:21:32.810 a, with a, you know, a beer and a brown paper 496 00:21:32.810 --> 00:21:34.929 bag and a packet of cigarettes. That'll be 497 00:21:34.929 --> 00:21:37.810 the end of the sun. But the bigger they 498 00:21:37.810 --> 00:21:39.650 get, the more possibilities. 499 00:21:41.170 --> 00:21:44.010 Professor Fred Watson: Yes, exactly. Um, look, um, the 500 00:21:44.010 --> 00:21:46.160 sun, uh, is a non smoker 501 00:21:46.800 --> 00:21:49.680 but it will do 502 00:21:49.680 --> 00:21:52.240 something similar because it 503 00:21:52.400 --> 00:21:55.080 will puff off its outer 504 00:21:55.080 --> 00:21:55.600 layers. 505 00:21:56.080 --> 00:21:58.440 Andrew Dunkley: Well that happens to all of us. We get fat as 506 00:21:58.440 --> 00:21:59.520 we retire. So 507 00:22:01.200 --> 00:22:02.240 that's what I'm saying. 508 00:22:02.400 --> 00:22:04.720 Professor Fred Watson: Yeah, yeah. It puffs off its outer layers, 509 00:22:04.720 --> 00:22:07.320 it'll become a white dwarf, will be the 510 00:22:07.320 --> 00:22:09.680 nucleus which itself is an exotic object. 511 00:22:10.080 --> 00:22:11.960 That's something the size of Earth but with 512 00:22:11.960 --> 00:22:14.880 the mass of the sun. Um, um, 513 00:22:15.270 --> 00:22:17.960 um, but its outer envelope will turn into 514 00:22:17.960 --> 00:22:20.480 something very beautiful. Probably what we 515 00:22:20.480 --> 00:22:21.760 call a planetary nebula. 516 00:22:22.240 --> 00:22:23.600 Andrew Dunkley: Yeah, we won't think so. 517 00:22:23.920 --> 00:22:25.960 Professor Fred Watson: We might not, but this will be a long time 518 00:22:25.960 --> 00:22:27.640 after we're gone because we'll have been 519 00:22:27.640 --> 00:22:28.320 swallowed up. 520 00:22:28.720 --> 00:22:31.720 Andrew Dunkley: Exactly. But um, as far 521 00:22:31.720 --> 00:22:34.240 as a neutron star is concerned, you've got 522 00:22:34.560 --> 00:22:37.400 a lot of density in a very small package 523 00:22:37.400 --> 00:22:40.280 with a hell of a lot of gravity. And um, the 524 00:22:40.280 --> 00:22:41.960 easiest thing to do there would be to climb 525 00:22:41.960 --> 00:22:43.760 the mountains. But I wouldn't recommend it. 526 00:22:46.100 --> 00:22:47.060 Professor Fred Watson: No, quite so. 527 00:22:47.140 --> 00:22:50.140 Andrew Dunkley: But the bottom line for Colin is um, bits 528 00:22:50.140 --> 00:22:51.820 might break off in the collision but the 529 00:22:51.820 --> 00:22:54.420 gravity is so intense they get sucked back 530 00:22:54.420 --> 00:22:56.740 in. So no, we don't have to worry about 531 00:22:56.820 --> 00:22:59.260 flying pieces of neutron star hitting Earth 532 00:22:59.260 --> 00:23:01.220 while you're trying to sleep. I mean that 533 00:23:01.220 --> 00:23:04.140 wouldn't be fun at all. Thanks Colin. 534 00:23:04.140 --> 00:23:05.140 Thank you for your question. 535 00:23:05.300 --> 00:23:07.940 Our final question today comes from Bill 536 00:23:08.340 --> 00:23:10.820 in relation. Now this was an audio question 537 00:23:10.820 --> 00:23:13.300 that Bill sent in, but the audio quality 538 00:23:14.060 --> 00:23:17.040 um, was super muff for some reason. 539 00:23:17.280 --> 00:23:20.200 And um, we couldn't use the 540 00:23:20.200 --> 00:23:23.200 audio Bill. But um, sometimes these 541 00:23:23.200 --> 00:23:25.970 things get messed up in the ether. So um, 542 00:23:26.640 --> 00:23:28.840 I listened to it about four or five times and 543 00:23:28.840 --> 00:23:31.530 I hope your name is actually Bill. Uh, 544 00:23:32.480 --> 00:23:34.880 and I hope I got uh, the words right in the 545 00:23:34.880 --> 00:23:36.600 question. But he's basically saying in 546 00:23:36.600 --> 00:23:39.560 relation to the Artemis astronauts witnessing 547 00:23:39.560 --> 00:23:41.560 the solar eclipse and seeing the sun's 548 00:23:41.560 --> 00:23:44.080 corona, would you see the same effect 549 00:23:44.160 --> 00:23:46.920 standing on the moon during a lunar 550 00:23:46.920 --> 00:23:49.520 sunset? And uh, Bill's in, in Dover And 551 00:23:49.520 --> 00:23:51.640 Judy and I were in Dover last year. It's 552 00:23:51.640 --> 00:23:54.120 absolutely wonderful there. Went to Dover 553 00:23:54.120 --> 00:23:56.040 Castle, went down into the World War II 554 00:23:56.040 --> 00:23:57.840 tunnels. Although they've been around a lot 555 00:23:57.840 --> 00:24:00.720 longer than that. Fascinating um, place 556 00:24:00.720 --> 00:24:03.110 and the white cliffs and looked out over um, 557 00:24:03.560 --> 00:24:06.120 over the English um, Channel and it was a 558 00:24:06.120 --> 00:24:08.980 clear day so I could see France. Uh, 559 00:24:08.980 --> 00:24:11.270 yeah. Um, something I've always wanted to 560 00:24:11.580 --> 00:24:14.140 witness. The locals are probably saying, oh 561 00:24:14.140 --> 00:24:16.540 gosh, he's boring. I can see that every day. 562 00:24:18.220 --> 00:24:19.940 Professor Fred Watson: They might like to see a kangaroo though, 563 00:24:19.940 --> 00:24:21.180 which you could see every day. 564 00:24:21.180 --> 00:24:24.180 Andrew Dunkley: Yeah, you know, um, it's 565 00:24:24.180 --> 00:24:25.260 a pest species. 566 00:24:25.420 --> 00:24:25.900 Professor Fred Watson: Yes. 567 00:24:25.920 --> 00:24:28.580 Andrew Dunkley: Uh, because, um, they've really 568 00:24:28.580 --> 00:24:31.180 adapted to um, uh, life 569 00:24:31.660 --> 00:24:34.380 post, um, modern agriculture and um. 570 00:24:34.460 --> 00:24:37.220 Yeah, they're doing well. M. 571 00:24:37.340 --> 00:24:40.060 So, um, yes. So 572 00:24:40.060 --> 00:24:40.540 yeah. 573 00:24:40.780 --> 00:24:42.620 Now we'll go back to the Artemis astronauts 574 00:24:42.620 --> 00:24:44.320 because they did see, ah, when they went 575 00:24:44.320 --> 00:24:47.040 around the moon, they saw um, um, a lunar 576 00:24:47.040 --> 00:24:49.960 eclipse and witnessed the corona. They saw 577 00:24:49.960 --> 00:24:51.880 a few other interesting things as well, like 578 00:24:52.280 --> 00:24:54.560 impact, um, flashes on the lunar surface from 579 00:24:54.560 --> 00:24:57.370 micrometeorites. Uh, but yeah, 580 00:24:57.370 --> 00:24:59.640 um, could you see the same effect 581 00:24:59.800 --> 00:25:01.240 standing on the moon? 582 00:25:02.250 --> 00:25:04.920 Professor Fred Watson: Um, yes. The answer is yes, 583 00:25:05.000 --> 00:25:07.240 because the moon doesn't have an atmosphere. 584 00:25:08.090 --> 00:25:10.880 Um, what there is on the 585 00:25:10.880 --> 00:25:13.600 moon is something called levitating 586 00:25:13.600 --> 00:25:16.040 regolith, uh, which is 587 00:25:16.760 --> 00:25:19.720 soil being lifted as a lunar soil particle. 588 00:25:19.800 --> 00:25:22.120 Basically the lunar dust, very, very fine 589 00:25:22.120 --> 00:25:25.119 dust. Um, and that gets 590 00:25:25.119 --> 00:25:27.920 electrostatically charged up during the lunar 591 00:25:27.920 --> 00:25:30.440 day and tends to fly off the 592 00:25:30.440 --> 00:25:31.000 surface. 593 00:25:31.480 --> 00:25:33.120 Andrew Dunkley: And that's why it ends up in your pina 594 00:25:33.120 --> 00:25:33.880 colada. 595 00:25:34.440 --> 00:25:36.360 Professor Fred Watson: It could be. Yes, that's right. 596 00:25:37.470 --> 00:25:40.450 Uh, so that's right. Uh, so, 597 00:25:40.870 --> 00:25:43.850 um, there could be a little bit 598 00:25:43.850 --> 00:25:46.850 of a dust haze, uh, on the moon 599 00:25:47.090 --> 00:25:49.490 which might spoil your view of the corona. 600 00:25:49.890 --> 00:25:52.050 That's the only thing that I could think of 601 00:25:52.050 --> 00:25:54.290 that would, um. 602 00:25:54.740 --> 00:25:57.450 Uh, it's certainly true that um, the Apollo 603 00:25:57.450 --> 00:26:00.450 astronauts, several of them, yes, witnessing 604 00:26:00.530 --> 00:26:03.530 the. Looking for exactly what we're talking 605 00:26:03.530 --> 00:26:05.650 about the corona of the sun as it rises 606 00:26:06.600 --> 00:26:09.240 above the limb of the moon. They could see 607 00:26:09.240 --> 00:26:12.080 this lunar dust being illuminated 608 00:26:12.080 --> 00:26:14.950 and that's how we know it happens. Um, 609 00:26:15.160 --> 00:26:18.080 there are some quite well known sketches made 610 00:26:18.080 --> 00:26:20.360 by some of the astronauts because it's very, 611 00:26:20.360 --> 00:26:23.040 very faint and with the cameras they had at 612 00:26:23.040 --> 00:26:25.080 that time, it wasn't possible to 613 00:26:25.320 --> 00:26:28.040 directly uh, record it, but there were 614 00:26:28.040 --> 00:26:30.800 sketches that they made. So it wasn't a 615 00:26:30.800 --> 00:26:33.400 solar phenomenon, it's this levitating dust. 616 00:26:34.160 --> 00:26:37.160 Um, but I think you'd see the 617 00:26:37.160 --> 00:26:39.560 lunar corona as well from the surface. 618 00:26:39.720 --> 00:26:40.280 Andrew Dunkley: Okay. 619 00:26:40.280 --> 00:26:42.160 Professor Fred Watson: Maybe one day somebody will find out because 620 00:26:42.160 --> 00:26:44.360 at the moment we've never had a human 621 00:26:44.360 --> 00:26:47.320 Watching a lunar sunset or moon. Sorry? 622 00:26:47.720 --> 00:26:49.880 A lunar sunset or sunrise. 623 00:26:50.439 --> 00:26:53.320 Andrew Dunkley: Yes, yeah, it'll happen, It'll happen. 624 00:26:53.320 --> 00:26:53.600 Professor Fred Watson: It will. 625 00:26:53.600 --> 00:26:55.600 Andrew Dunkley: Uh, yes, you know the way they're talking, 626 00:26:55.600 --> 00:26:58.160 within a very short period of time, there 627 00:26:58.160 --> 00:27:01.120 will be permanent habitation on the moon 628 00:27:01.120 --> 00:27:03.770 of some kind. Research stations, maybe, um, 629 00:27:05.120 --> 00:27:07.280 power generators, I don't know. They've got. 630 00:27:07.440 --> 00:27:10.240 There's a lot to do and as we mentioned in 631 00:27:10.240 --> 00:27:11.920 the last episode, there's, uh. They're 632 00:27:11.920 --> 00:27:13.360 already looking at ways of building 633 00:27:13.600 --> 00:27:16.000 infrastructure on the. On the moon using. 634 00:27:16.160 --> 00:27:19.040 Using moon dust. So, um. Yeah, 635 00:27:19.040 --> 00:27:21.400 we'll get there. I was going to say 636 00:27:21.400 --> 00:27:23.040 eventually, but I don't think it'll be 637 00:27:23.040 --> 00:27:25.320 eventual. I think it's. We're at the dawn of 638 00:27:25.320 --> 00:27:25.600 it. 639 00:27:25.600 --> 00:27:27.440 Professor Fred Watson: Yep. So exciting. 640 00:27:27.920 --> 00:27:30.040 Andrew Dunkley: M. But yes, a sunset on the moon could be. 641 00:27:30.040 --> 00:27:32.640 Could be quite fascinating. And thank you, 642 00:27:32.640 --> 00:27:34.880 Bill, for your question. Hope all is well in 643 00:27:35.040 --> 00:27:37.340 Dover. And if got questions for us, please 644 00:27:37.340 --> 00:27:39.580 send them in to us via our website, 645 00:27:39.580 --> 00:27:42.380 spacenutspodcast.com or 646 00:27:42.380 --> 00:27:44.940 spacenuts IO. Click on the 647 00:27:44.940 --> 00:27:47.820 AMA button at the top and, uh, that means 648 00:27:47.820 --> 00:27:50.140 ask me anything. And you can send in text 649 00:27:50.140 --> 00:27:52.620 questions or audio questions. If you've got a 650 00:27:52.620 --> 00:27:54.740 device with a microphone, you're all set. And 651 00:27:54.740 --> 00:27:57.260 that's just about everything these days. And, 652 00:27:57.420 --> 00:27:59.180 um, don't forget to tell us who you are and 653 00:27:59.180 --> 00:28:00.620 where you're from and have a look around on 654 00:28:00.620 --> 00:28:02.160 our website while you're there. And, um, 655 00:28:02.380 --> 00:28:04.900 please leave reviews wherever you listen to 656 00:28:04.900 --> 00:28:07.420 us because they help, apparently. I don't 657 00:28:07.420 --> 00:28:08.860 know what they help with. Probably someone 658 00:28:08.860 --> 00:28:11.800 else getting paid, I don't know. But, um, 659 00:28:11.800 --> 00:28:14.620 yes, reviews are always good. They move us up 660 00:28:14.620 --> 00:28:16.380 the pecking order. Number one in Iceland. 661 00:28:17.540 --> 00:28:20.540 Um, but yeah, uh, it's all good stuff. 662 00:28:20.860 --> 00:28:22.660 And Fred Watson, thank you so much. It's been 663 00:28:22.660 --> 00:28:23.260 good to talk. 664 00:28:24.140 --> 00:28:26.620 Professor Fred Watson: It has. It's been a, um, great pleasure as 665 00:28:26.620 --> 00:28:26.940 always. 666 00:28:27.820 --> 00:28:29.380 Andrew Dunkley: We'll catch you soon. Professor Fred Watson 667 00:28:29.380 --> 00:28:31.060 Watson, astronomer at large. And thanks to 668 00:28:31.060 --> 00:28:33.340 Huw in the studio, who couldn't be with us 669 00:28:33.340 --> 00:28:35.960 today because he likes pina coladas and walks 670 00:28:35.960 --> 00:28:38.000 in the rain. Not much into health food, but 671 00:28:38.000 --> 00:28:39.800 he's into champagne. That's why he's under 672 00:28:39.800 --> 00:28:42.000 the table. Couldn't join us today. And from 673 00:28:42.000 --> 00:28:43.800 me, Andrew Dunkley, thanks for your company. 674 00:28:44.360 --> 00:28:46.760 Some people will get that joke. See you on 675 00:28:46.760 --> 00:28:48.400 the next episode of Space Nuts. 676 00:28:48.400 --> 00:28:49.080 Professor Fred Watson: Bye. Bye. 677 00:28:50.280 --> 00:28:52.520 Andrew Dunkley: You've been listening to the Space Nuts 678 00:28:52.520 --> 00:28:55.480 podcast, available at 679 00:28:55.480 --> 00:28:57.480 Apple Podcasts, Spotify, 680 00:28:57.720 --> 00:28:59.890 iHeartRadio or your favourite favourite 681 00:28:59.890 --> 00:29:02.450 podcast player. You can also stream On Demand 682 00:29:02.450 --> 00:29:03.410 at bytes. 683 00:29:03.410 --> 00:29:03.810 Professor Fred Watson: Com. 684 00:29:04.130 --> 00:29:06.210 Andrew Dunkley: This has been another quality podcast 685 00:29:06.210 --> 00:29:08.000 production from Bytes. Com. 686 00:29:08.000 --> 00:29:08.030 Speaker C: Um,