WEBVTT 0 00:00:00.960 --> 00:00:03.280 Andrew Dunkley: 15 seconds. Guidance is internal. 1 00:00:03.520 --> 00:00:06.240 10, 9. Ignition 2 00:00:06.240 --> 00:00:07.200 sequence start. 3 00:00:07.360 --> 00:00:08.800 Professor Fred Watson: Space nuts I. 4 00:00:09.040 --> 00:00:11.998 Andrew Dunkley: 4, 3, 2, 5 00:00:12.202 --> 00:00:15.120 1. Space nuts. Astronauts 6 00:00:15.120 --> 00:00:18.000 reported meals Good. Hello once again 7 00:00:18.720 --> 00:00:20.920 and thank you for joining us on this edition 8 00:00:20.920 --> 00:00:23.200 of the Space Nuts podcast. 9 00:00:23.920 --> 00:00:25.960 And my name's Andrew Dudley, your host. And 10 00:00:25.960 --> 00:00:28.640 with Me for episode 193 is 11 00:00:28.800 --> 00:00:31.440 Astronomer in Charge from Professor Fred 12 00:00:31.440 --> 00:00:33.080 Watson. Hello, Fred. 13 00:00:33.720 --> 00:00:35.600 Professor Fred Watson: Hello, Andrew. I did used to be the 14 00:00:35.600 --> 00:00:37.200 Astronomer in charge. That was my. 15 00:00:37.200 --> 00:00:38.680 Andrew Dunkley: I thought I said Astronomer at Large. 16 00:00:39.000 --> 00:00:40.120 Professor Fred Watson: Well, it's quite all right. 17 00:00:40.120 --> 00:00:42.120 Andrew Dunkley: No, it's Freudian slip. 18 00:00:42.120 --> 00:00:44.870 Professor Fred Watson: It's very. And of course, um, uh, 19 00:00:44.870 --> 00:00:46.559 that's why I became the Astronomer at Large. 20 00:00:46.559 --> 00:00:48.200 Because you only had to change four letters 21 00:00:48.200 --> 00:00:50.440 on the office door to make it unknown to you. 22 00:00:51.560 --> 00:00:52.600 Yes, yes. 23 00:00:52.650 --> 00:00:55.200 Andrew Dunkley: Um, the organ. And that sort of harps on 24 00:00:55.200 --> 00:00:57.240 something we talked about a while ago where 25 00:00:57.400 --> 00:00:59.680 your organization has changed names about two 26 00:00:59.680 --> 00:01:02.200 or three times, but didn't change the 27 00:01:02.200 --> 00:01:04.040 lettering. So didn't change the logo. 28 00:01:04.200 --> 00:01:06.280 Professor Fred Watson: Exactly. Same logo since 29 00:01:06.280 --> 00:01:07.320 1991. 30 00:01:09.320 --> 00:01:12.239 Andrew Dunkley: I think that's amazing. Uh, very 31 00:01:12.239 --> 00:01:12.600 good. 32 00:01:12.680 --> 00:01:14.960 Now, um, Fred, have you got enough toilet 33 00:01:14.960 --> 00:01:16.520 paper at your place? Is my big question. 34 00:01:17.880 --> 00:01:20.190 Professor Fred Watson: Well, it's very kind of you to ask. Um, 35 00:01:20.600 --> 00:01:23.480 we haven't yet started tearing pages out the 36 00:01:23.480 --> 00:01:25.720 Astrophysical Journal to use in the bathroom. 37 00:01:26.200 --> 00:01:27.880 Andrew Dunkley: Did you hear about the Northern Territory 38 00:01:27.880 --> 00:01:30.260 News? Uh, the newspaper in Darwin? 39 00:01:32.420 --> 00:01:34.500 They published an edition last week with 40 00:01:34.500 --> 00:01:36.100 several blank pages for people. 41 00:01:40.020 --> 00:01:42.780 This whole thing is just insanity at the 42 00:01:42.780 --> 00:01:45.220 highest level. There's so many people 43 00:01:45.220 --> 00:01:47.380 panicking over nothing. It's. 44 00:01:49.140 --> 00:01:50.980 Professor Fred Watson: You might want to explain the toilet paper 45 00:01:50.980 --> 00:01:51.540 issue, though. 46 00:01:51.940 --> 00:01:53.780 Andrew Dunkley: I think most people are aware, but if you're 47 00:01:53.780 --> 00:01:55.260 not aware, I don't know where you've been. 48 00:01:55.260 --> 00:01:57.420 But, uh, there's been a panic buy up of 49 00:01:57.420 --> 00:02:00.090 toilet paper in Australia and all the 50 00:02:00.320 --> 00:02:02.160 supermarket shelves are empty. Every 51 00:02:02.320 --> 00:02:04.600 supermarket where I live has got no toilet 52 00:02:04.600 --> 00:02:07.040 paper because people have been panic buying 53 00:02:07.040 --> 00:02:09.720 because the prime minister said stock up 54 00:02:09.720 --> 00:02:11.600 because you might have to be isolated for a 55 00:02:11.600 --> 00:02:12.960 couple of weeks because of the coronavirus. 56 00:02:13.440 --> 00:02:15.600 And everyone's freaking out about it. Well, 57 00:02:15.600 --> 00:02:17.960 not everyone. I mean, we don't care. But a 58 00:02:17.960 --> 00:02:19.640 lot of people are freaking out about it. But, 59 00:02:19.640 --> 00:02:22.600 uh, I'm going to bring some astronomy 60 00:02:22.600 --> 00:02:23.360 into this, Fred. 61 00:02:23.520 --> 00:02:25.440 Professor Fred Watson: Oh, good. I wondered where it was going. 62 00:02:25.600 --> 00:02:28.160 Andrew Dunkley: I think this is the 2020 version 63 00:02:28.910 --> 00:02:31.270 of a caveman seeing an eclipse and thinking 64 00:02:31.270 --> 00:02:34.110 the world's going to end. Oh, probably that's 65 00:02:34.110 --> 00:02:34.830 what this is. 66 00:02:35.230 --> 00:02:35.790 Professor Fred Watson: Yeah. 67 00:02:36.110 --> 00:02:38.910 Andrew Dunkley: So I think people need to take a long, hard 68 00:02:38.910 --> 00:02:40.710 look at themselves and give themselves an 69 00:02:40.710 --> 00:02:43.590 uppercut, to use an Australian term, and just 70 00:02:43.590 --> 00:02:46.070 get on with it. This is 71 00:02:46.070 --> 00:02:48.430 ridiculous. Totally ridiculous. 72 00:02:49.630 --> 00:02:51.620 Professor Fred Watson: The good news is that um, 73 00:02:52.750 --> 00:02:54.850 those particular people will, you know, 74 00:02:54.850 --> 00:02:56.130 they'll never need to go and buy another 75 00:02:56.130 --> 00:02:57.410 toilet roll again. 76 00:02:57.490 --> 00:03:00.410 Andrew Dunkley: Not for eternity. They'll 77 00:03:00.410 --> 00:03:02.450 get like, they'll get buried with the stuff. 78 00:03:02.690 --> 00:03:03.490 Professor Fred Watson: Yeah, that's right. 79 00:03:03.650 --> 00:03:05.290 Andrew Dunkley: I'm suggesting that if they're going to, you 80 00:03:05.290 --> 00:03:07.290 know, panic, buy toilet paper, get some baked 81 00:03:07.290 --> 00:03:09.290 beans and some long life milk so that when 82 00:03:09.290 --> 00:03:11.170 you eat it it'll taste a bit better. 83 00:03:13.460 --> 00:03:15.170 M Now let's get down to business. 84 00:03:15.250 --> 00:03:18.090 Today on Space Nuts we're going to uh, look 85 00:03:18.090 --> 00:03:20.050 at something that scientists have discovered 86 00:03:20.050 --> 00:03:22.340 for the first time and that is that space 87 00:03:22.340 --> 00:03:24.780 time is dragging. Not everywhere, but they've 88 00:03:24.780 --> 00:03:26.820 found that it is dragging in one particular 89 00:03:26.980 --> 00:03:29.820 place, which sounds unusual. And what does 90 00:03:29.820 --> 00:03:32.700 dragging actually mean? Uh, we're also going 91 00:03:32.700 --> 00:03:34.900 to look at a couple of clever, uh, students, 92 00:03:35.200 --> 00:03:38.140 um, uh, in terms of a name for the 93 00:03:38.140 --> 00:03:40.620 next Martian rover. This follows on from 94 00:03:40.620 --> 00:03:42.620 Sojourner, which I think is a great name. 95 00:03:42.620 --> 00:03:45.140 Spirit, Opportunity, Curiosity. So what are 96 00:03:45.140 --> 00:03:47.060 they calling the next one? We will tell you. 97 00:03:47.460 --> 00:03:50.100 And a 17 year old intern at 98 00:03:50.100 --> 00:03:53.100 NASA Day 3 on the job has 99 00:03:53.100 --> 00:03:55.820 found a planet six times, uh, or nearly seven 100 00:03:55.820 --> 00:03:58.140 times larger than Earth. I mean, 101 00:03:58.700 --> 00:04:01.020 how lucky is that? Uh, those are some of the 102 00:04:01.020 --> 00:04:03.420 things we'll look at today on Space Nuts with 103 00:04:03.500 --> 00:04:04.460 Fred Watson. 104 00:04:04.460 --> 00:04:07.460 Let's uh, start off Fred, with um, the 105 00:04:07.460 --> 00:04:10.420 fact that space time is dragging. What is it 106 00:04:10.420 --> 00:04:12.140 dragging and why? 107 00:04:13.570 --> 00:04:16.540 Professor Fred Watson: Uh, it's a phenomenon 108 00:04:16.620 --> 00:04:19.319 to do with the theory of general 109 00:04:19.319 --> 00:04:21.399 relativity, or rather the general theory of 110 00:04:21.399 --> 00:04:23.679 relativity, which of course was produced by 111 00:04:23.679 --> 00:04:26.639 Albert Einstein in 1915. Uh, not 112 00:04:26.639 --> 00:04:28.359 long after that, I think about three years 113 00:04:28.359 --> 00:04:31.039 later. Well, uh, let me just step back a 114 00:04:31.039 --> 00:04:34.038 minute. That theory of course says that 115 00:04:34.038 --> 00:04:36.799 as soon as you put matter into space time 116 00:04:37.279 --> 00:04:40.159 and space time's really just space, but with 117 00:04:40.159 --> 00:04:43.039 a fancy name as, uh, soon as you put matter 118 00:04:43.039 --> 00:04:44.799 into it, because of course time's part of it 119 00:04:44.799 --> 00:04:47.039 as well. Uh, as soon as you put matter into 120 00:04:47.039 --> 00:04:49.630 space time it is distorted and that 121 00:04:49.630 --> 00:04:52.420 distortion is what we feel as gravity. Uh, 122 00:04:52.420 --> 00:04:55.310 and that in itself is pretty hard to 123 00:04:55.310 --> 00:04:57.550 get your head around. Space time bends 124 00:04:57.550 --> 00:05:00.430 because matters there. But it was about, 125 00:05:00.680 --> 00:05:02.830 uh, I think three years later 126 00:05:03.550 --> 00:05:05.630 that two Austrian 127 00:05:05.950 --> 00:05:08.470 scientists, uh, by the name of 128 00:05:08.470 --> 00:05:11.310 Josef Lenzer unt Hans Turing, 129 00:05:12.080 --> 00:05:14.750 um, they worked out that 130 00:05:15.140 --> 00:05:16.970 uh, you would get a phenomenon, 131 00:05:17.560 --> 00:05:20.370 um, if you have a 132 00:05:20.370 --> 00:05:22.850 massive object rotating, you get a 133 00:05:22.850 --> 00:05:25.810 phenomenon which is almost a swirling of 134 00:05:25.810 --> 00:05:28.450 the space time around the object. It's called 135 00:05:28.450 --> 00:05:31.130 frame dragging. Um, and 136 00:05:31.210 --> 00:05:33.970 so as the Earth does it, as the Earth 137 00:05:33.970 --> 00:05:36.810 turns, it's not only distorting the 138 00:05:36.810 --> 00:05:39.730 space that's holding us on with the Force 139 00:05:39.730 --> 00:05:42.170 of gravity, but to a much less, 140 00:05:42.870 --> 00:05:45.110 a much lesser degree, it's also 141 00:05:45.350 --> 00:05:48.110 dragging the surrounding space time with 142 00:05:48.110 --> 00:05:51.030 it. Now I know you're 143 00:05:51.030 --> 00:05:52.310 looking baffled, Andrew. 144 00:05:52.790 --> 00:05:54.910 Andrew Dunkley: It's just a lack of sleep because I'm worried 145 00:05:54.910 --> 00:05:56.590 about where I'm going to get a roll of toilet 146 00:05:56.590 --> 00:05:57.030 paper. 147 00:05:58.070 --> 00:06:01.070 Professor Fred Watson: Well, just watch out. Don't drag your space 148 00:06:01.070 --> 00:06:03.270 time with it when you find it. 149 00:06:03.830 --> 00:06:06.310 Um, we usually Anglicize, 150 00:06:06.550 --> 00:06:09.430 uh, uh, Josef and Hans 151 00:06:09.430 --> 00:06:11.950 names to the lens theory 152 00:06:12.190 --> 00:06:14.590 precession or lens theorying effect. 153 00:06:14.830 --> 00:06:15.390 Andrew Dunkley: Okay. 154 00:06:15.610 --> 00:06:18.510 Professor Fred Watson: Um, that's um, how most people speak of 155 00:06:18.510 --> 00:06:19.670 it, even though they wouldn't have called 156 00:06:19.670 --> 00:06:22.170 themselves that. Uh, so, uh, 157 00:06:22.270 --> 00:06:25.030 okay, it has been tested, this 158 00:06:25.030 --> 00:06:27.950 theory. It was um, as I said, I think it 159 00:06:27.950 --> 00:06:30.910 was 1918 when it was uh, when 160 00:06:30.910 --> 00:06:33.150 it was produced. Um, but 161 00:06:34.190 --> 00:06:36.870 uh, the first test of it was 162 00:06:36.870 --> 00:06:39.770 done in the early 2000s. 163 00:06:39.770 --> 00:06:42.370 A spacecraft called Gravity Probe B 164 00:06:42.930 --> 00:06:45.490 was launched into orbit around the Earth 165 00:06:45.650 --> 00:06:47.770 by NASA in collaboration, I think with 166 00:06:47.770 --> 00:06:49.670 Stanford University, um, 167 00:06:50.450 --> 00:06:53.210 which carried on board very, very sensitive 168 00:06:53.210 --> 00:06:56.130 gyroscopes. And by using 169 00:06:56.210 --> 00:06:58.290 those, uh, the 170 00:06:59.130 --> 00:07:01.970 uh, physicists running the experiment could 171 00:07:01.970 --> 00:07:04.690 detect the frame dragging of the Earth 172 00:07:04.690 --> 00:07:07.360 itself. So it's all about subtle 173 00:07:07.360 --> 00:07:10.280 motions in the satellite 174 00:07:10.440 --> 00:07:13.400 and that tells you that yes, you have proved, 175 00:07:13.560 --> 00:07:15.640 because there's nothing else that would give 176 00:07:15.640 --> 00:07:17.960 rise to those subtle motions, you've proved 177 00:07:17.960 --> 00:07:20.660 that frame dragging is true, uh, 178 00:07:21.080 --> 00:07:23.560 but it's only been detected around the Earth. 179 00:07:24.120 --> 00:07:26.680 So now cut to the chase, uh, because 180 00:07:27.000 --> 00:07:29.800 uh, for the first time, uh, it has 181 00:07:29.800 --> 00:07:32.760 now been detected in an astronomical object. 182 00:07:33.460 --> 00:07:36.230 Uh, and this is a really nice story because 183 00:07:36.390 --> 00:07:39.310 it pulls together uh, the 184 00:07:39.310 --> 00:07:41.990 fundamental physics of frame dragging with 185 00:07:42.150 --> 00:07:44.990 some of the big adventures that here 186 00:07:44.990 --> 00:07:47.890 in Australia we are taking part in, uh, 187 00:07:47.910 --> 00:07:50.350 particularly in terms of radio astronomy. The 188 00:07:50.350 --> 00:07:52.630 story goes back 20 years actually, Andrew, 189 00:07:53.070 --> 00:07:55.310 uh, to the Parkes Radio 190 00:07:55.310 --> 00:07:58.070 Observatory, uh, in New South 191 00:07:58.070 --> 00:08:00.710 Wales, the very same state that we are both 192 00:08:01.030 --> 00:08:01.990 in at the moment. 193 00:08:03.030 --> 00:08:04.790 Andrew Dunkley: One hour drive from that telescope. 194 00:08:05.060 --> 00:08:06.820 Professor Fred Watson: Yeah, yeah, that's right. You are indeed. 195 00:08:06.820 --> 00:08:09.170 Exactly. It's just down the road for you. Ah, 196 00:08:09.170 --> 00:08:11.740 very, very well known telescope, uh, the Big 197 00:08:11.740 --> 00:08:12.820 Dish it's usually called. 198 00:08:12.980 --> 00:08:15.060 Andrew Dunkley: And very distracting when you're driving 199 00:08:15.060 --> 00:08:16.900 along the highway because you just want to 200 00:08:16.900 --> 00:08:17.380 look at it. 201 00:08:17.380 --> 00:08:19.140 Professor Fred Watson: You can't stop looking at it. I know 202 00:08:20.899 --> 00:08:22.380 I don't have that problem because usually 203 00:08:22.380 --> 00:08:24.020 when I go down there, that's where I'm going. 204 00:08:24.660 --> 00:08:27.340 So I just watch it getting bigger as you get 205 00:08:27.340 --> 00:08:30.100 nearer to it. Um, 20 years ago, 206 00:08:30.410 --> 00:08:33.020 uh, the Parkes radio telescope 207 00:08:33.020 --> 00:08:35.940 discovered uh, a white 208 00:08:35.940 --> 00:08:38.180 dwarf pulsar binary system. 209 00:08:38.649 --> 00:08:41.620 Um, I'll tell you its name and then we can 210 00:08:41.620 --> 00:08:43.380 get that out of the way. It is, actually. 211 00:08:43.380 --> 00:08:45.340 I've got to magnify the screen so I can read 212 00:08:45.340 --> 00:08:45.700 it. 213 00:08:48.820 --> 00:08:51.750 Now, Fred, you're showing your PSR, uh, 214 00:08:51.750 --> 00:08:54.740 J1141 minus 6545. 215 00:08:54.740 --> 00:08:57.300 There you are. Uh, put that in your diary. 216 00:08:57.620 --> 00:09:00.460 That's good already. As have 217 00:09:00.460 --> 00:09:03.260 I. Uh, it is a white dwarf pulsar, uh, binary 218 00:09:03.260 --> 00:09:04.800 system. What does that mean? It means you've 219 00:09:04.800 --> 00:09:07.720 got a white dwarf star, which is, um, an 220 00:09:07.720 --> 00:09:09.880 object the size of the Earth, but with the 221 00:09:09.880 --> 00:09:12.560 mass of a star in it. Uh, made of electrons 222 00:09:12.560 --> 00:09:14.920 all crushed together. Uh, or the electrons 223 00:09:14.920 --> 00:09:17.000 are the only thing that hold that. Hold the 224 00:09:17.000 --> 00:09:18.720 thing that start the thing from collapsing. 225 00:09:19.200 --> 00:09:22.130 So, um, that is a massive object. Uh, 226 00:09:22.400 --> 00:09:24.680 around it is this pulsar, which is another 227 00:09:24.680 --> 00:09:27.450 massive object, uh, a neutron star. Uh, 228 00:09:27.520 --> 00:09:30.320 the two are in mutual orbits and 229 00:09:31.090 --> 00:09:33.570 the, uh. So the 230 00:09:33.570 --> 00:09:35.810 telescope discovered that 231 00:09:36.130 --> 00:09:39.010 phenomenon, the binary system. So the 232 00:09:39.010 --> 00:09:41.210 pulsar itself is beaming out radiation from 233 00:09:41.210 --> 00:09:43.770 its poles. Pulsars, as you know, because you 234 00:09:43.770 --> 00:09:45.990 and I have spoken about this before, uh, 235 00:09:45.990 --> 00:09:48.690 effectively are extremely accurate clocks. 236 00:09:49.090 --> 00:09:51.650 They basically blip out 237 00:09:51.650 --> 00:09:54.210 radio radiation as they rotate. 238 00:09:54.290 --> 00:09:56.210 That's what the Parkes dish detected. 239 00:09:57.170 --> 00:10:00.130 And, um, the precision with which 240 00:10:00.130 --> 00:10:02.650 they do that is better than atomic clocks. 241 00:10:02.890 --> 00:10:05.890 They are so regular. Um, Just 242 00:10:05.890 --> 00:10:08.650 as one smaller piece of information in this. 243 00:10:08.650 --> 00:10:11.610 The pulsar itself orbits the white 244 00:10:11.610 --> 00:10:14.090 dwarf every 4.8 hours. 245 00:10:14.730 --> 00:10:17.450 So it's, you know, it's a. It's 246 00:10:17.450 --> 00:10:20.190 whizzing round. That's right. Um, 247 00:10:20.250 --> 00:10:23.130 now what has happened over the last 20 years 248 00:10:23.210 --> 00:10:25.860 is that astronomers have been able to use 249 00:10:26.420 --> 00:10:28.500 this timing phenomenon, 250 00:10:29.140 --> 00:10:31.220 the regular timing of the pulsar, 251 00:10:31.860 --> 00:10:34.820 to measure the pulsar's 252 00:10:34.820 --> 00:10:37.420 position in respect to the white 253 00:10:37.420 --> 00:10:39.540 dwarf. Uh, because 254 00:10:40.260 --> 00:10:42.620 essentially time. Accurate time means 255 00:10:42.620 --> 00:10:45.140 accurate distance in terms of, uh, measuring 256 00:10:45.780 --> 00:10:48.260 where the pulsar is. And it's that 257 00:10:48.580 --> 00:10:51.060 measured over 20 years that has 258 00:10:51.060 --> 00:10:53.820 demonstrated that this frame dragging 259 00:10:53.820 --> 00:10:56.300 phenomenon is taking place out there, 260 00:10:56.850 --> 00:10:59.180 uh, at PSR, whatever it was. Uh, 261 00:10:59.180 --> 00:11:01.500 J1141 minus 6545. 262 00:11:02.510 --> 00:11:05.460 Um, so what the 263 00:11:05.460 --> 00:11:07.420 scientists. And there's a group of scientists 264 00:11:07.420 --> 00:11:09.740 from, uh, many different institutions, 265 00:11:09.900 --> 00:11:12.860 including, uh, institutions in Germany, the 266 00:11:13.020 --> 00:11:15.860 Square Kilometer Array Organization. That 267 00:11:15.860 --> 00:11:18.650 is, uh, the headquarters of this great 268 00:11:18.650 --> 00:11:20.850 new telescope that we're planning, the Square 269 00:11:20.850 --> 00:11:23.690 Kilometer Array in Western Australia and in 270 00:11:23.850 --> 00:11:26.370 South Africa. Uh, the headquarters are in 271 00:11:26.370 --> 00:11:28.570 Manchester, uh, or near Manchester at the 272 00:11:28.570 --> 00:11:31.010 Jodrell Bank Radio Observatory. One of the 273 00:11:31.010 --> 00:11:33.370 scientists involved with this work, uh, comes 274 00:11:33.370 --> 00:11:36.170 from that organization. Uh, so that 275 00:11:36.170 --> 00:11:39.170 means, uh, he is relatively closely connected 276 00:11:39.170 --> 00:11:41.530 with Australia because Australia is one of 277 00:11:41.530 --> 00:11:44.450 the host nations. Uh, and 278 00:11:44.450 --> 00:11:46.570 I should just mention that the Parkes dish, 279 00:11:46.850 --> 00:11:48.720 uh, plus another telescope called the 280 00:11:48.720 --> 00:11:51.280 Malonglo Observatory Synthesis Telescope 281 00:11:51.280 --> 00:11:54.040 again here in Australia, uh, which has been 282 00:11:54.040 --> 00:11:55.680 involved with this work. They are both 283 00:11:56.400 --> 00:11:58.240 Pathfinder telescopes for the Square 284 00:11:58.240 --> 00:12:00.080 Kilometer Array. So very important 285 00:12:00.880 --> 00:12:03.720 in this large scale project that 286 00:12:03.720 --> 00:12:06.480 is currently uh, under construction or, 287 00:12:06.650 --> 00:12:09.000 uh, soon will be under construction, um, 288 00:12:09.520 --> 00:12:12.240 that's getting in the plug for ska. But the 289 00:12:12.240 --> 00:12:14.640 research itself, as I said, involves 290 00:12:14.640 --> 00:12:16.880 scientists from Germany, Australia, New 291 00:12:16.880 --> 00:12:19.760 Zealand and actually Denmark too. Um, and 292 00:12:19.760 --> 00:12:22.320 what they've done is they've um, looked at 293 00:12:22.320 --> 00:12:25.280 the way these pulsar signals have changed 294 00:12:25.280 --> 00:12:28.200 over the 20 years and they find 295 00:12:28.440 --> 00:12:30.760 a change in the pulsar's 296 00:12:30.760 --> 00:12:33.080 orbit which amounts to 297 00:12:33.880 --> 00:12:36.800 150 kilometers. Uh, and 298 00:12:36.800 --> 00:12:38.360 we're now talking about something that's 299 00:12:38.360 --> 00:12:41.240 10,000 light years away. Andrews Being 300 00:12:41.240 --> 00:12:44.080 able to measure uh, a change in orbit of 301 00:12:44.080 --> 00:12:47.080 150 kilometers, uh, at that distance is 302 00:12:47.080 --> 00:12:49.960 an astonishing accomplishment. But it turns 303 00:12:49.960 --> 00:12:52.560 out that that change is exactly what you 304 00:12:52.560 --> 00:12:55.440 would expect from frame dragging by 305 00:12:55.440 --> 00:12:57.560 the white dwarf itself. And that's the only 306 00:12:57.560 --> 00:12:59.960 thing that can account for it. So it is the 307 00:12:59.960 --> 00:13:02.320 first time that we've demonstrated this 308 00:13:02.320 --> 00:13:05.250 swirling of space actually, uh, uh, 309 00:13:05.250 --> 00:13:07.400 beyond the Earth's vicinity. And it's an 310 00:13:07.400 --> 00:13:09.040 important, um, you know, a really important 311 00:13:09.040 --> 00:13:11.720 result which is rightly being celebrated all 312 00:13:11.720 --> 00:13:14.440 over the science media, um, astronomers, 313 00:13:14.440 --> 00:13:16.680 detective, Distant space time dragging for 314 00:13:16.680 --> 00:13:17.600 the first time. 315 00:13:17.840 --> 00:13:20.760 Andrew Dunkley: So I guess the point of 316 00:13:20.760 --> 00:13:23.720 this is the massive um, or the 317 00:13:23.720 --> 00:13:26.240 mass of this event rather than, you know, we 318 00:13:26.240 --> 00:13:28.520 talked about how Earth does it, but we're 319 00:13:28.520 --> 00:13:30.520 talking about something on a much larger 320 00:13:30.520 --> 00:13:30.880 scale. 321 00:13:31.600 --> 00:13:33.600 Professor Fred Watson: That's right, yes. Uh, well, the white dwarf 322 00:13:33.600 --> 00:13:35.600 itself, whilst it's probably not much bigger 323 00:13:35.600 --> 00:13:38.160 than the Earth, uh, its mass is much larger. 324 00:13:38.160 --> 00:13:40.720 Yeah, uh, and yeah, you're talking about, 325 00:13:40.900 --> 00:13:42.520 um, you know, you are talking about something 326 00:13:42.520 --> 00:13:45.200 happening on a larger scale. I 327 00:13:45.200 --> 00:13:47.870 confess that um, I am not an 328 00:13:47.870 --> 00:13:50.790 expert on the lens searing effect, uh, but 329 00:13:50.870 --> 00:13:53.710 it is very interesting stuff. Uh, and when 330 00:13:53.710 --> 00:13:56.030 you read up about it, it's quite inspiring 331 00:13:56.030 --> 00:13:58.310 that, you know, all those years ago these 332 00:13:58.310 --> 00:14:00.670 guys worked out that space time is being 333 00:14:00.670 --> 00:14:01.990 dragged around by the Earth. 334 00:14:02.310 --> 00:14:04.830 Andrew Dunkley: And if you like me and you don't want to read 335 00:14:04.830 --> 00:14:06.550 anything about it, there's a fabulous 336 00:14:06.550 --> 00:14:07.830 animation on the 337 00:14:08.390 --> 00:14:11.230 skatelescope.org website where you 338 00:14:11.230 --> 00:14:14.230 can see um, in about 1 minute 339 00:14:14.230 --> 00:14:16.230 and 20 seconds what they've learned over 20 340 00:14:16.230 --> 00:14:19.130 years. It shows you how uh, effect works. 341 00:14:19.130 --> 00:14:20.050 It's very, very good. 342 00:14:21.730 --> 00:14:23.450 Professor Fred Watson: Um, I might give a call out to the, the 343 00:14:23.450 --> 00:14:25.650 person who put that uh, animation together, 344 00:14:25.650 --> 00:14:27.970 Mark Myers, who's at Swinburne University, 345 00:14:28.650 --> 00:14:29.930 uh, because I was in touch with him 346 00:14:29.930 --> 00:14:32.890 yesterday. I'm using one of his, um, graphics 347 00:14:32.890 --> 00:14:35.250 in a newsletter that I prepare and I asked 348 00:14:35.250 --> 00:14:38.030 him if that was all right. He said he, uh, 349 00:14:38.250 --> 00:14:40.770 was delighted to let us use it. And 350 00:14:41.490 --> 00:14:43.730 I absolutely agree with you, Andrew. His 351 00:14:43.730 --> 00:14:45.930 animation, uh, which is on that website, the 352 00:14:45.930 --> 00:14:48.370 skatelescope.org website, is terrific. 353 00:14:48.600 --> 00:14:49.240 Andrew Dunkley: Yes, indeed. 354 00:14:49.240 --> 00:14:51.760 All right, you're listening to the Space 355 00:14:51.760 --> 00:14:54.440 Nuts podcast. Andrew Dunkley here with Fred 356 00:14:54.440 --> 00:14:57.360 Watson. Let's 357 00:14:57.360 --> 00:14:59.600 take a break from the show and hear a word or 358 00:14:59.600 --> 00:15:02.280 two from our sponsored Grammarly. Now, I have 359 00:15:02.280 --> 00:15:04.919 to say I'm a big fan of Grammarly uh, because 360 00:15:04.920 --> 00:15:07.280 I've been using it for a few years now. Very 361 00:15:07.280 --> 00:15:09.880 helpful for authors, but, uh, also really 362 00:15:09.880 --> 00:15:12.120 good for everyday life. They've saved me on a 363 00:15:12.120 --> 00:15:14.480 few occasions. 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Uh, Grammarly explains the 380 00:15:56.080 --> 00:15:58.760 reasoning behind each correction so you can 381 00:15:58.760 --> 00:16:01.400 make an informed decision about whether and 382 00:16:01.400 --> 00:16:03.520 how to correct an issue. 383 00:16:04.000 --> 00:16:06.760 Grammarly helps you write mistake free 384 00:16:06.760 --> 00:16:09.200 gmail, Facebook, Twitter, LinkedIn, 385 00:16:09.440 --> 00:16:11.960 and nearly anything else you write on the 386 00:16:11.960 --> 00:16:14.710 web. Uh, for you, the listener of Spacenuts 387 00:16:14.710 --> 00:16:16.790 Grammarly is offering a free download of the 388 00:16:16.790 --> 00:16:19.310 Grammarly software. So if you'd like to 389 00:16:19.310 --> 00:16:21.430 download Grammarly today, go to 390 00:16:21.430 --> 00:16:23.684 getgrammarly.com spacenuts 391 00:16:23.922 --> 00:16:26.865 again, that's getgrammarly.com 392 00:16:27.193 --> 00:16:30.150 spacEnuts to download Grammarly 393 00:16:30.150 --> 00:16:32.990 for free and let them know you came from 394 00:16:32.990 --> 00:16:35.710 us. Uh, I'll include the link in the show 395 00:16:35.710 --> 00:16:36.390 notes as well. 396 00:16:36.550 --> 00:16:38.710 And now back to Space Nuts. 397 00:16:39.590 --> 00:16:41.670 Three, two, one. 398 00:16:42.230 --> 00:16:45.190 Space Nuts. Now, Fred, uh, just, 399 00:16:45.210 --> 00:16:47.630 uh, another shout out to our patrons who 400 00:16:47.630 --> 00:16:50.150 support our podcast with dollars and cents. 401 00:16:50.150 --> 00:16:52.830 We, um, thank you again for doing that. If 402 00:16:52.830 --> 00:16:54.989 you would like to become a patron or just 403 00:16:54.989 --> 00:16:57.390 look into the possibility, uh, you can go to 404 00:16:57.390 --> 00:16:59.510 Our Patreon website, patreon.com 405 00:16:59.830 --> 00:17:02.110 spacenuts all the information's there. If you 406 00:17:02.110 --> 00:17:04.350 would like to contribute to the program, you 407 00:17:04.350 --> 00:17:07.270 can set your own limit. Um, but 408 00:17:07.630 --> 00:17:09.830 it's not mandatory. We're not asking you to 409 00:17:09.830 --> 00:17:12.630 do it as, as a condition of listening to the 410 00:17:12.630 --> 00:17:14.910 podcast. If you want to go on listening to 411 00:17:14.910 --> 00:17:17.710 it, uh, as you are, that is fine too. 412 00:17:17.710 --> 00:17:20.230 But uh, anybody who contributes does get the 413 00:17:20.230 --> 00:17:22.630 benefit of bonus content on the Patreon 414 00:17:22.630 --> 00:17:25.390 website. Uh, they also get the commercial 415 00:17:25.390 --> 00:17:27.470 free edition of the podcast, 416 00:17:28.010 --> 00:17:30.790 uh, ahead of time. So, um, something to 417 00:17:30.790 --> 00:17:33.670 consider anyway, um, now, uh, by the 418 00:17:33.670 --> 00:17:36.430 way, Fred, um, my uh, new book, 419 00:17:37.750 --> 00:17:40.690 um, Shameless Plug coming up, uh, is now 420 00:17:40.690 --> 00:17:43.530 available for pre order as an 421 00:17:43.530 --> 00:17:46.370 ebook. So, um, have a look for that 422 00:17:46.450 --> 00:17:49.230 on the Amazon website. So, um, 423 00:17:49.230 --> 00:17:52.210 that's, that's pretty exciting. I very, very 424 00:17:52.210 --> 00:17:54.080 pleased with how it's all turned out. Uh, 425 00:17:54.080 --> 00:17:55.970 someone actually messaged me the other day 426 00:17:55.970 --> 00:17:57.730 and said I've ordered it, better be good. 427 00:17:59.680 --> 00:18:01.330 Professor Fred Watson: Uh, you've got to remind us of the title, 428 00:18:01.330 --> 00:18:01.730 Andrew. 429 00:18:01.730 --> 00:18:04.640 Andrew Dunkley: It's called, uh, the Turanian Enigma. The 430 00:18:04.640 --> 00:18:07.560 Tyranny Enigma. I'm starting. First time I 431 00:18:07.560 --> 00:18:09.920 wrote that down and read it out, my tongue 432 00:18:09.920 --> 00:18:11.560 tripped over it and I thought, no, this is, 433 00:18:11.640 --> 00:18:14.080 this is too hard. But I'm getting used to it 434 00:18:14.080 --> 00:18:14.360 now. 435 00:18:15.000 --> 00:18:15.600 Professor Fred Watson: Very good. 436 00:18:15.600 --> 00:18:17.440 Andrew Dunkley: I've developed a couple of synapses in my 437 00:18:17.440 --> 00:18:19.240 brain that have got my mouth around the 438 00:18:19.240 --> 00:18:21.820 Turanian in. No, no, I tripped over it. But 439 00:18:21.820 --> 00:18:24.240 um, yeah, have a look for it. Uh, the 440 00:18:24.240 --> 00:18:27.240 official release date of the ebook and 441 00:18:28.040 --> 00:18:30.440 the paperback will be April 15th. 442 00:18:31.710 --> 00:18:34.710 And um, a few people have 443 00:18:34.710 --> 00:18:36.830 asked if I could turn it into an audiobook as 444 00:18:36.830 --> 00:18:39.710 well. So I'll look into that. It's just 445 00:18:39.710 --> 00:18:41.950 so time consuming to create an audiobook. 446 00:18:42.510 --> 00:18:45.230 Uh, not so much the reading and recording of, 447 00:18:45.230 --> 00:18:47.990 but the editing. Oh my gosh, that's a 448 00:18:47.990 --> 00:18:49.390 nightmare. Uh, having. 449 00:18:49.390 --> 00:18:51.230 Professor Fred Watson: Well, you did that for, um, almost. 450 00:18:51.230 --> 00:18:54.150 Andrew Dunkley: There's Mud, which was a World 451 00:18:54.150 --> 00:18:56.150 War I story about my grandfather in the Great 452 00:18:56.150 --> 00:18:58.920 War. But that, that started 453 00:18:59.080 --> 00:19:01.880 as an audiobook. So that was. I sort 454 00:19:01.880 --> 00:19:04.120 of flipped the egg on that. I did the 455 00:19:04.120 --> 00:19:07.000 audiobook and then, uh, made the paperback. 456 00:19:07.240 --> 00:19:09.360 But these last two I've done the other way 457 00:19:09.360 --> 00:19:10.920 around or haven't done the other way around. 458 00:19:10.920 --> 00:19:13.560 But um, I'll, I'll look into it. I'll just. 459 00:19:13.640 --> 00:19:16.560 It's got to be feasible. And that, 460 00:19:16.560 --> 00:19:19.480 that sort of becomes the question. But, um, 461 00:19:19.800 --> 00:19:22.120 we'll see how the demand goes. But yeah, have 462 00:19:22.120 --> 00:19:24.560 a look for it. Um, Huw tells me he's going to 463 00:19:24.560 --> 00:19:26.910 put it on our um, bytes.com 464 00:19:27.150 --> 00:19:29.670 spacenuts page. So you might be able to pre 465 00:19:29.670 --> 00:19:31.950 order through there. I haven't checked. 466 00:19:32.320 --> 00:19:34.310 Uh, now let's get down to a couple of things 467 00:19:34.310 --> 00:19:36.790 involving students. Fred. These are, uh, 468 00:19:36.980 --> 00:19:39.390 um, exciting stories. I particularly like 469 00:19:39.390 --> 00:19:41.909 this one, which involves the naming of the 470 00:19:41.909 --> 00:19:44.590 next Mars rover. Now we've uh, heard of 471 00:19:44.590 --> 00:19:47.230 Sojourner and Spirit and Opportunity and 472 00:19:47.230 --> 00:19:50.030 Curiosity, uh some of which 473 00:19:50.190 --> 00:19:52.830 have gone above and beyond the call of duty. 474 00:19:53.520 --> 00:19:56.470 Uh, but um, they aren't the last rovers. 475 00:19:56.470 --> 00:19:59.070 They'll be future rovers. And uh, it looks 476 00:19:59.070 --> 00:20:00.790 like some students have got involved in the 477 00:20:00.790 --> 00:20:01.870 naming of the next one. 478 00:20:02.990 --> 00:20:05.660 Professor Fred Watson: Well, that's right. It was uh, uh, 479 00:20:05.720 --> 00:20:08.510 uh, you know, I think this is what NASA 480 00:20:08.510 --> 00:20:11.430 does normally with its rovers. Uh, it puts 481 00:20:11.430 --> 00:20:14.380 out a um, competition, uh, 482 00:20:14.510 --> 00:20:17.230 to uh, actually to 483 00:20:17.230 --> 00:20:19.790 school students, uh, and 484 00:20:20.030 --> 00:20:22.670 says suggests names for our next 485 00:20:22.670 --> 00:20:25.240 rover. And of course the next rover is 486 00:20:25.560 --> 00:20:27.880 what's been called until now Mars 2020. 487 00:20:28.380 --> 00:20:31.080 Um, it will be launched uh, July or August 488 00:20:31.080 --> 00:20:33.720 this year. I think its landing date 489 00:20:33.960 --> 00:20:36.960 on Mars is the 18th of February next 490 00:20:36.960 --> 00:20:39.960 year. So, um, uh, just under a year 491 00:20:39.960 --> 00:20:42.560 away until now, called Mars 492 00:20:42.560 --> 00:20:45.400 2020. So during the closing 493 00:20:45.400 --> 00:20:48.080 months of last year, NASA put out the 494 00:20:48.080 --> 00:20:50.780 invitation to school 495 00:20:50.780 --> 00:20:53.460 students, I think it was, uh, school students 496 00:20:53.460 --> 00:20:56.460 of all ages from kindy to year 12. 497 00:20:57.270 --> 00:20:59.500 Uh, and uh, invited 498 00:21:00.540 --> 00:21:02.460 them to submit 499 00:21:03.100 --> 00:21:03.900 suggestions 500 00:21:06.030 --> 00:21:08.660 uh, for the um, name, uh, of the 501 00:21:08.660 --> 00:21:10.380 rover. And they received 502 00:21:11.510 --> 00:21:13.340 uh, 28,000 503 00:21:13.740 --> 00:21:14.700 submissions. 504 00:21:14.700 --> 00:21:16.220 Andrew Dunkley: I know, that's amazing. 505 00:21:16.700 --> 00:21:19.540 Professor Fred Watson: It's not bad, is it? That was uh, back in 506 00:21:19.540 --> 00:21:21.140 August, at the end of August last year when 507 00:21:21.140 --> 00:21:23.880 they put the invitation out. Uh, 508 00:21:24.060 --> 00:21:26.500 but fortunately, uh, it wasn't just one 509 00:21:26.500 --> 00:21:28.500 person who had to read all 28,000 because 510 00:21:28.500 --> 00:21:30.620 these were essays, uh, saying why it should 511 00:21:30.620 --> 00:21:33.100 be a particular name. They had 4,700 512 00:21:33.100 --> 00:21:35.730 volunteer judges. They were educators, uh, 513 00:21:35.980 --> 00:21:38.740 professionals in the space field and space 514 00:21:38.740 --> 00:21:41.460 enthusiasts. And they eventually got down 515 00:21:41.460 --> 00:21:44.030 to 155 semi 516 00:21:44.030 --> 00:21:46.190 finalists and then nine finalists. And I 517 00:21:46.190 --> 00:21:48.070 think, I can't remember, but I think you and 518 00:21:48.070 --> 00:21:50.950 I talked about this last year because 519 00:21:50.950 --> 00:21:53.790 there was a list of uh, very elegant. They 520 00:21:53.790 --> 00:21:56.350 were all great names actually for uh, a 521 00:21:56.350 --> 00:21:56.790 rover. 522 00:21:56.870 --> 00:21:57.510 Andrew Dunkley: Robert. 523 00:21:58.690 --> 00:22:00.950 Professor Fred Watson: Uh, and then they put that out for public 524 00:22:00.950 --> 00:22:03.710 voting and in fact it was worldwide and there 525 00:22:03.710 --> 00:22:05.910 were many submissions came from Australia. 526 00:22:06.550 --> 00:22:08.350 They received a total of 527 00:22:08.350 --> 00:22:10.870 770,000 votes 528 00:22:12.070 --> 00:22:14.700 to, to, you know, to chew through, to work 529 00:22:14.700 --> 00:22:17.580 out what uh, the final name should be. 530 00:22:17.980 --> 00:22:20.780 And eventually, uh, they 531 00:22:20.780 --> 00:22:23.260 got one answer and it came. 532 00:22:23.340 --> 00:22:25.900 Andrew Dunkley: Hang on, Drumroll, drumroll. 533 00:22:25.950 --> 00:22:28.950 Professor Fred Watson: Uh, it came from uh, 534 00:22:29.580 --> 00:22:32.300 a youngster by the name of Alex 535 00:22:32.620 --> 00:22:35.420 Mather, uh, who's at a school. I've 536 00:22:35.420 --> 00:22:37.460 forgotten. I think he's in Virginia. I can 537 00:22:37.460 --> 00:22:40.280 check that in a minute. Uh, but he. And 538 00:22:40.280 --> 00:22:42.560 here's the drum roll. He was the person who 539 00:22:42.560 --> 00:22:45.120 suggested the name Perseverance, 540 00:22:45.440 --> 00:22:47.920 which is nice of the new 541 00:22:48.240 --> 00:22:49.840 spacecraft. Yeah, yeah. 542 00:22:50.000 --> 00:22:52.240 Andrew Dunkley: That is a fabulous name for it because it 543 00:22:52.240 --> 00:22:55.040 does actually tell a story 544 00:22:55.040 --> 00:22:57.080 behind all the missions to Mars over the 545 00:22:57.080 --> 00:22:58.800 years and all the work that's gone into it. 546 00:22:58.800 --> 00:23:01.600 They just, you know, uh, all the successes 547 00:23:01.600 --> 00:23:04.530 and the failures and the near misses. It 548 00:23:04.530 --> 00:23:07.050 is Perseverance that's going. 549 00:23:07.370 --> 00:23:10.290 Professor Fred Watson: That's right. I mean this spacecraft as well 550 00:23:10.290 --> 00:23:12.850 could be uh, it could be the one that 551 00:23:12.850 --> 00:23:15.450 discovers life on Mars because 552 00:23:15.450 --> 00:23:18.410 that's what it's, you know, what the aim is. 553 00:23:18.770 --> 00:23:21.490 Um, uh, unlike Curiosity, whose mission was 554 00:23:21.490 --> 00:23:24.090 to discover whether Mars was ever habitable, 555 00:23:24.090 --> 00:23:26.130 which it did within about the first fortnight 556 00:23:26.130 --> 00:23:28.950 of its presence on the planet, um, uh, 557 00:23:29.050 --> 00:23:31.970 Perseverance is looking for evidence of past 558 00:23:31.970 --> 00:23:34.490 or present life, um, with many different 559 00:23:34.490 --> 00:23:37.490 instruments that will, will do that. Uh, 560 00:23:37.670 --> 00:23:40.310 and I suspect perseverance might be 561 00:23:40.630 --> 00:23:42.590 the characteristic that it needs more than 562 00:23:42.590 --> 00:23:44.630 anything else. It will probably be quite a 563 00:23:44.630 --> 00:23:46.830 long mission. Uh, it's unlikely that, you 564 00:23:46.830 --> 00:23:48.590 know, as soon as it drops down it's going to 565 00:23:48.590 --> 00:23:51.390 find evidence of um, Martian 566 00:23:51.390 --> 00:23:53.590 microbes. One would expect that it might have 567 00:23:53.590 --> 00:23:55.630 to move around on the surface a bit, but it 568 00:23:55.630 --> 00:23:56.230 will do that. 569 00:23:58.150 --> 00:24:00.910 Andrew Dunkley: Only slightly pipped, uh, the number 570 00:24:00.910 --> 00:24:03.500 two, which was Do I have to go to Mars? 571 00:24:05.340 --> 00:24:07.460 Professor Fred Watson: Yeah, that's the one. 572 00:24:07.460 --> 00:24:10.220 Andrew Dunkley: Yeah. Um, I'm fascinated by the fact 573 00:24:10.220 --> 00:24:12.980 that uh, they got 28,000 submissions for the 574 00:24:12.980 --> 00:24:14.820 name. It reminds me of an author, a 575 00:24:14.820 --> 00:24:16.740 children's author in Sri Lanka last week who 576 00:24:16.740 --> 00:24:19.380 got 20,000 submissions for the ending of her 577 00:24:19.380 --> 00:24:22.140 latest book. And they came out 578 00:24:22.380 --> 00:24:24.140 and they're going to publish it with 579 00:24:24.140 --> 00:24:27.020 1,250 endings, which is, 580 00:24:27.620 --> 00:24:30.020 which is a, um, Guinness World Record. And I, 581 00:24:30.020 --> 00:24:32.540 I think those sorts of responses really show 582 00:24:32.540 --> 00:24:34.820 where you stand in the world. So when I asked 583 00:24:34.820 --> 00:24:36.660 for a title for my book, I got five. 584 00:24:36.900 --> 00:24:39.140 Professor Fred Watson: Yeah, you did. I think that's pretty good. 585 00:24:40.500 --> 00:24:42.260 More than, more than the number of people who 586 00:24:42.260 --> 00:24:45.150 read my book. Um, um, 587 00:24:45.540 --> 00:24:47.740 the bottom line here is congratulations to 588 00:24:47.740 --> 00:24:50.740 young Alexander Mather. He 589 00:24:50.740 --> 00:24:53.740 is uh, a year, sorry a grade 590 00:24:53.740 --> 00:24:56.240 seven student. Now I, I'm, I'm guessing that 591 00:24:56.240 --> 00:24:58.960 that means he's about 13, uh, or 592 00:24:58.960 --> 00:25:00.680 thereabouts. Um, and 593 00:25:01.840 --> 00:25:04.200 uh, he put in, put together a really 594 00:25:04.840 --> 00:25:07.440 uh, remarkable, um, you know, 595 00:25:07.440 --> 00:25:10.080 remarkable uh, um, 596 00:25:10.520 --> 00:25:12.920 entry. Um, he said some 597 00:25:13.240 --> 00:25:15.560 very, very, very uh, 598 00:25:15.840 --> 00:25:18.720 nice comments about the, the competition. And 599 00:25:18.720 --> 00:25:21.420 his, his uh, his, his um 600 00:25:21.800 --> 00:25:24.630 entry to it, he says, um, this 601 00:25:24.630 --> 00:25:26.270 is actually in the NASA press release. He 602 00:25:26.270 --> 00:25:28.190 says this was a chance to help the agency 603 00:25:28.190 --> 00:25:30.150 that put humans on the moon and we'll soon do 604 00:25:30.150 --> 00:25:32.910 it again. This Mars rover will help pave the 605 00:25:32.910 --> 00:25:35.310 way for human presence there. And I wanted to 606 00:25:35.310 --> 00:25:38.270 Try and help in any way I could. Refusal of 607 00:25:38.270 --> 00:25:39.990 the challenge was not an option. 608 00:25:40.790 --> 00:25:43.350 Lovely. That is great stuff, isn't it? 609 00:25:43.350 --> 00:25:45.990 Andrew Dunkley: Good on him. Okay, uh, so watch out for 610 00:25:46.150 --> 00:25:49.070 perseverance, uh, which should hit 611 00:25:49.070 --> 00:25:51.830 the Martian surface in little under a year. 612 00:25:52.630 --> 00:25:55.030 Still, uh, on students doing great things. 613 00:25:55.330 --> 00:25:58.170 Uh, this is a fabulous story about a 17 year 614 00:25:58.170 --> 00:26:01.130 old who's doing an internship at NASA and 615 00:26:01.130 --> 00:26:03.890 has found a planet on day 616 00:26:03.890 --> 00:26:04.290 three. 617 00:26:04.610 --> 00:26:07.490 Professor Fred Watson: Day three. That's right, it is. 618 00:26:07.490 --> 00:26:10.210 It's great stuff. Um, so, uh, this 619 00:26:10.210 --> 00:26:13.130 is a young man called, uh, Wolf, Cukier, 620 00:26:13.130 --> 00:26:14.930 I hope I'm pronouncing his name correctly. 621 00:26:15.350 --> 00:26:17.170 Uh, he scored a two month 622 00:26:17.570 --> 00:26:20.530 internship with NASA. Uh, so during 623 00:26:20.530 --> 00:26:22.570 last northern summer he was at the Goddard 624 00:26:22.570 --> 00:26:24.930 Space Flight center in Greenbelt in Maryland. 625 00:26:25.490 --> 00:26:28.450 And, um, what he was doing, uh, on 626 00:26:28.450 --> 00:26:30.490 day three, I think he probably started off 627 00:26:30.490 --> 00:26:33.450 doing this. He was trawling through data from 628 00:26:33.690 --> 00:26:36.530 tess. Uh, so TESS is a 629 00:26:36.530 --> 00:26:39.130 NASA spacecraft. It is currently operational, 630 00:26:39.530 --> 00:26:42.409 doing a great job. The name is an acronym 631 00:26:42.409 --> 00:26:45.210 for Transiting Exoplanet Survey Satellite. 632 00:26:45.210 --> 00:26:48.090 So it's actually looking for the dimming 633 00:26:48.090 --> 00:26:50.970 of the light of stars as planets 634 00:26:50.970 --> 00:26:53.970 pass in front of them. And unlike Kepler, 635 00:26:53.970 --> 00:26:56.870 which only looked at a small, uh, 636 00:26:56.870 --> 00:26:59.530 area of the sky to do the same job, 637 00:27:00.250 --> 00:27:03.190 Kepler, now effectively defunct tess, uh, 638 00:27:03.770 --> 00:27:06.490 actually looks at the whole sky. Uh, so 639 00:27:07.850 --> 00:27:10.250 the word survey in its name is very important 640 00:27:10.330 --> 00:27:12.170 because it actually has a chance to look at 641 00:27:12.170 --> 00:27:14.970 the entire sky. So he was looking 642 00:27:15.530 --> 00:27:17.730 through the data. Actually there's a nice 643 00:27:17.730 --> 00:27:20.610 quote again, um, from Wolf. He 644 00:27:20.610 --> 00:27:22.790 says, I was looking through the data for 645 00:27:22.790 --> 00:27:24.670 everything the volunteers had flagged as an 646 00:27:24.670 --> 00:27:27.150 eclipsing binary. That means, uh, 647 00:27:27.510 --> 00:27:29.990 two stars orbiting around their common center 648 00:27:29.990 --> 00:27:32.950 of mass. One passes in front of the other as 649 00:27:32.950 --> 00:27:35.150 seen from the Earth. And so you get what we 650 00:27:35.150 --> 00:27:38.030 call an eclipse. So they're well known stars. 651 00:27:38.030 --> 00:27:40.830 They've been well known for more than a 652 00:27:40.830 --> 00:27:43.270 century. It was looking, uh, through 653 00:27:43.270 --> 00:27:45.310 everything Volunteers had flagged as an 654 00:27:45.310 --> 00:27:47.630 eclipsing binary. A system where two stars 655 00:27:47.630 --> 00:27:49.800 circle around each other and from our view, 656 00:27:49.800 --> 00:27:52.520 eclipse each other every orbit. About 657 00:27:52.520 --> 00:27:55.320 three days into my internship, I saw a signal 658 00:27:55.320 --> 00:27:57.360 from a system called TOI 659 00:27:57.360 --> 00:28:00.320 1338. At first I thought it was a 660 00:28:00.320 --> 00:28:03.000 stellar eclipse, but the timing was 661 00:28:03.000 --> 00:28:05.560 wrong. It turned out to be a planet. 662 00:28:06.000 --> 00:28:08.760 Uh, I noticed a dip or a transit from the TOI 663 00:28:08.760 --> 00:28:11.200 1338 system. And that was the first signal of 664 00:28:11.200 --> 00:28:13.440 the planet. First saw the initial dip and 665 00:28:13.440 --> 00:28:16.400 thought, oh, that looked cool. But then when 666 00:28:16.400 --> 00:28:18.400 I looked at the full data from the telescope 667 00:28:18.400 --> 00:28:20.970 at that start, I and my mentor also 668 00:28:20.970 --> 00:28:23.010 noticed three different dips in the system. 669 00:28:23.010 --> 00:28:25.890 So great stuff and very well 670 00:28:25.890 --> 00:28:26.410 spotted. 671 00:28:26.410 --> 00:28:27.890 Andrew Dunkley: And it's a big one too. 672 00:28:28.530 --> 00:28:29.250 Professor Fred Watson: Yeah, that's right. 673 00:28:29.650 --> 00:28:30.530 Andrew Dunkley: Planets, I suppose. 674 00:28:32.140 --> 00:28:34.650 Professor Fred Watson: Um, it's somewhere between the size of 675 00:28:34.650 --> 00:28:37.460 Neptune and Saturn. Uh, 676 00:28:37.890 --> 00:28:40.730 rather larger than Uranus, about seven 677 00:28:40.730 --> 00:28:43.050 times larger than the Earth. It's in the 678 00:28:43.050 --> 00:28:45.410 constellation of Pictor and it's about 1300 679 00:28:45.410 --> 00:28:46.290 light years away. 680 00:28:46.950 --> 00:28:49.940 Andrew Dunkley: Um, is it a gas giant or a rocky planet? 681 00:28:49.940 --> 00:28:52.420 Professor Fred Watson: Probably. Probably a gas giant. Yeah. 682 00:28:53.460 --> 00:28:56.290 The name, uh, uh, uh, 683 00:28:56.290 --> 00:28:59.220 TOI 1338. TOI 684 00:28:59.220 --> 00:29:02.020 is an acronym for TESS, Object of 685 00:29:02.020 --> 00:29:04.790 Interest. Uh, and, uh, um, 686 00:29:04.790 --> 00:29:06.740 it's one that's floating around a lot these 687 00:29:06.740 --> 00:29:09.540 days with a number attached to it. 688 00:29:09.540 --> 00:29:12.260 So of course, um, because of the convention, 689 00:29:12.470 --> 00:29:15.150 uh, that planet that, uh, Wolf has 690 00:29:15.150 --> 00:29:18.070 discovered is now called TOI1338B 691 00:29:18.310 --> 00:29:20.750 because the B signifies it is the first 692 00:29:20.750 --> 00:29:22.870 discovered planet around the star. 693 00:29:23.270 --> 00:29:24.630 Andrew Dunkley: Excellent. All right. 694 00:29:24.950 --> 00:29:25.630 Professor Fred Watson: Great stuff. 695 00:29:25.630 --> 00:29:27.550 Andrew Dunkley: Yeah, good, good stuff with involving 696 00:29:27.550 --> 00:29:30.550 students, um, doing wonderful things. You're 697 00:29:30.550 --> 00:29:32.950 listening to Space Nuts with Andrew Dunkley 698 00:29:32.950 --> 00:29:34.310 and Professor Fred Watson. 699 00:29:38.550 --> 00:29:41.330 Space Nuts and a big hello to all our 700 00:29:41.330 --> 00:29:43.880 social media followers that contribute, um, 701 00:29:44.490 --> 00:29:46.490 via our Facebook page. If you're not 702 00:29:46.490 --> 00:29:48.530 following us on Facebook, uh, maybe have a 703 00:29:48.530 --> 00:29:50.210 look. If you're a Facebook user, of course, 704 00:29:50.760 --> 00:29:53.450 uh, you can also join the Space Nuts podcast 705 00:29:53.450 --> 00:29:55.610 group on Facebook. That's a chance for you to 706 00:29:55.610 --> 00:29:57.610 talk to each other and help each other out 707 00:29:57.610 --> 00:29:59.370 with astronomy questions. And it's going 708 00:29:59.370 --> 00:30:02.290 gangbusters. People are really, uh, enjoying 709 00:30:02.850 --> 00:30:05.650 finding each other and, um, the 710 00:30:05.650 --> 00:30:08.290 similarity in interest is rather fascinating. 711 00:30:08.370 --> 00:30:10.970 So I occasionally poke my head in there. But 712 00:30:10.970 --> 00:30:13.310 it's actually for you, the Space Nuts podcast 713 00:30:13.310 --> 00:30:15.430 group, so you might want to take advantage of 714 00:30:15.430 --> 00:30:17.910 that. And of course YouTube Music. Uh, the 715 00:30:17.910 --> 00:30:19.830 numbers continue to grow, so if you'd like to 716 00:30:19.830 --> 00:30:22.790 subscribe to the Space Nuts YouTube Music 717 00:30:22.790 --> 00:30:24.910 channel, you can do that too. 718 00:30:25.870 --> 00:30:28.390 Now, Fred, uh, we have a couple of questions. 719 00:30:28.390 --> 00:30:30.430 I didn't, uh, preview these because I forgot, 720 00:30:30.430 --> 00:30:32.590 but, uh, we, we are going to tackle a couple 721 00:30:32.590 --> 00:30:34.300 of questions and then we're going to do, um, 722 00:30:34.300 --> 00:30:35.990 a little bit of homework or go back to 723 00:30:35.990 --> 00:30:37.350 something we talked about a couple of weeks 724 00:30:37.350 --> 00:30:39.730 ago just to finish it off, which was the 725 00:30:39.730 --> 00:30:41.850 Roche limit, which, which actually came about 726 00:30:41.850 --> 00:30:42.970 as a result of a question. 727 00:30:43.370 --> 00:30:45.290 But our first question today comes from 728 00:30:45.290 --> 00:30:47.370 Andrew Mitchell. I think Andrew's been in 729 00:30:47.370 --> 00:30:49.290 touch with us before. Dear Fred and Andrew, 730 00:30:49.290 --> 00:30:51.690 all this recent talk about black holes has 731 00:30:51.690 --> 00:30:54.170 been fascinating. And the last installment 732 00:30:54.170 --> 00:30:56.530 got me thinking. According to Einstein's 733 00:30:56.530 --> 00:30:58.730 equations, black holes are supposed to have, 734 00:30:58.880 --> 00:31:01.770 uh, infinite, uh, supposed to be infinitely 735 00:31:01.770 --> 00:31:04.490 small, infinitely dense singularities 736 00:31:04.730 --> 00:31:07.450 at their center. If that's the case, then how 737 00:31:07.530 --> 00:31:10.250 do uh, two actually merge into one black. 738 00:31:10.870 --> 00:31:12.670 Shouldn't they just keep orbiting each other, 739 00:31:12.670 --> 00:31:15.470 getting closer forever? Or is the fact that 740 00:31:15.470 --> 00:31:17.670 black holes do merge actually evidence that 741 00:31:17.670 --> 00:31:20.430 singularities have size? Perhaps a sphere 742 00:31:20.430 --> 00:31:23.270 with a diameter of one Planck length? 743 00:31:23.880 --> 00:31:25.870 Uh, your regular plugs and YouTube Music 744 00:31:25.870 --> 00:31:28.270 channel have been paying off. I just became 745 00:31:28.270 --> 00:31:30.910 subscriber number 993, so it would, you know, 746 00:31:30.910 --> 00:31:32.310 we're a bit overdue getting your question 747 00:31:32.310 --> 00:31:33.670 done, Andrew. Thanks for joining us on 748 00:31:33.670 --> 00:31:35.510 YouTube Music though still loving the show. 749 00:31:35.670 --> 00:31:38.550 Um, please keep up the mind blowing stories. 750 00:31:39.300 --> 00:31:41.780 Thank you, Andrew. Um, black holes, gee, we 751 00:31:41.780 --> 00:31:42.900 don't talk about them very often. 752 00:31:43.730 --> 00:31:46.420 Um, but yeah, it's an interesting 753 00:31:46.420 --> 00:31:49.220 question because we talk about how the, the 754 00:31:49.220 --> 00:31:52.100 black hole itself is quite small when 755 00:31:52.100 --> 00:31:54.779 you compare it to the event horizon or the, 756 00:31:54.779 --> 00:31:57.220 or the, you know, what's going on around it. 757 00:31:57.530 --> 00:32:00.420 Um, but yeah, two 758 00:32:00.420 --> 00:32:02.820 merging black holes, do they actually merge? 759 00:32:02.820 --> 00:32:04.740 And how is it. So. 760 00:32:07.190 --> 00:32:09.290 Professor Fred Watson: It'S a really good question. Um, 761 00:32:10.070 --> 00:32:10.630 it's, 762 00:32:12.870 --> 00:32:15.510 you know, the 763 00:32:15.670 --> 00:32:18.030 whole black hole thing is hard to get your 764 00:32:18.030 --> 00:32:20.710 head around, whether you're a physicist or an 765 00:32:20.710 --> 00:32:23.550 astronomer or somebody fighting 766 00:32:23.550 --> 00:32:25.750 over toilet rolls in the ah, aisle. 767 00:32:25.910 --> 00:32:28.310 Andrew Dunkley: Vesuva involves a black hole too, doesn't it? 768 00:32:28.310 --> 00:32:31.070 Professor Fred Watson: I'm sure it does, yeah. They are very, very 769 00:32:31.070 --> 00:32:33.920 hard, uh, objects to understand. Uh, 770 00:32:33.990 --> 00:32:35.270 and Andrew's question 771 00:32:36.930 --> 00:32:39.890 made, um, how do two black 772 00:32:39.890 --> 00:32:41.970 holes merge into one? 773 00:32:42.690 --> 00:32:45.250 Um, I don't think 774 00:32:46.130 --> 00:32:48.890 there is any need for them 775 00:32:48.890 --> 00:32:51.730 to keep orbiting around each other 776 00:32:51.730 --> 00:32:54.530 if they are of infinitely small 777 00:32:54.530 --> 00:32:56.490 size. I do get his point that if you've got 778 00:32:56.490 --> 00:32:59.370 something that's infinitely small, uh, and 779 00:32:59.370 --> 00:33:01.010 you put something else that's infinitely 780 00:33:01.010 --> 00:33:02.800 small next to it, they're never going to, 781 00:33:03.030 --> 00:33:05.950 they're never going to touch, uh, because 782 00:33:05.950 --> 00:33:08.910 the dimensions are infinitely small. But in 783 00:33:08.910 --> 00:33:11.830 fact, as Andrew says, they do merge. 784 00:33:11.830 --> 00:33:14.430 We have evidence of that, uh, from the 785 00:33:14.430 --> 00:33:16.910 gravitational wave observations that have 786 00:33:16.910 --> 00:33:19.350 been made, um, over the past, uh, two or 787 00:33:19.350 --> 00:33:21.350 three years. Um, and 788 00:33:22.080 --> 00:33:24.530 uh, there is this phenomenon, um, 789 00:33:25.350 --> 00:33:27.510 called the ring down, which is 790 00:33:28.230 --> 00:33:30.750 the sort of aftermath of the merging. Now I 791 00:33:30.750 --> 00:33:33.030 don't know enough about black hole physics to 792 00:33:33.680 --> 00:33:36.360 understand specifically what the mechanism of 793 00:33:36.360 --> 00:33:38.720 the ring down is, but I suspect that is where 794 00:33:39.120 --> 00:33:41.840 the evidence comes that you actually 795 00:33:41.920 --> 00:33:44.560 have now merged black holes. In fact, 796 00:33:45.200 --> 00:33:47.920 we know the evidence is there, um, because 797 00:33:48.000 --> 00:33:50.800 you wind up with a black hole whose mass 798 00:33:51.840 --> 00:33:54.120 is actually usually slightly less than the 799 00:33:54.120 --> 00:33:55.960 sum of the masses of the two black holes that 800 00:33:55.960 --> 00:33:58.960 have merged. And um, the excess has gone into 801 00:33:58.960 --> 00:34:01.480 creating the gravitational waves. It's mass 802 00:34:01.480 --> 00:34:04.150 into energy. Uh, but um, 803 00:34:04.260 --> 00:34:06.580 Andrew goes on to make an interesting point. 804 00:34:06.580 --> 00:34:09.580 He says, or is the 805 00:34:09.580 --> 00:34:11.620 fact that black holes do merge. Actually 806 00:34:11.700 --> 00:34:14.020 evidence that singularities have a size, 807 00:34:14.020 --> 00:34:16.860 perhaps a sphere with a diameter of one 808 00:34:16.860 --> 00:34:19.060 Planck length. Now 809 00:34:19.460 --> 00:34:22.020 introducing the Planck length is a 810 00:34:22.580 --> 00:34:25.180 really, ah, neat way of sidestepping the idea 811 00:34:25.180 --> 00:34:28.140 of an infinitesimally small object, 812 00:34:28.140 --> 00:34:31.130 because the Planck length is defined 813 00:34:31.690 --> 00:34:33.930 as being the smallest 814 00:34:34.090 --> 00:34:37.010 distance. And it does have a 815 00:34:37.010 --> 00:34:39.330 proper physical definition. In fact, it's 816 00:34:39.330 --> 00:34:41.970 actually the distance that light travels in 817 00:34:41.970 --> 00:34:44.730 one unit of Planck time. Uh, so that 818 00:34:44.890 --> 00:34:46.570 raises the question, well, what's Planck 819 00:34:46.570 --> 00:34:49.410 time? Um, let me just 820 00:34:49.410 --> 00:34:51.330 summarize though, and this is coming directly 821 00:34:51.330 --> 00:34:53.970 off Wikipedia. The Planck length can be 822 00:34:53.970 --> 00:34:56.820 defined. Uh, sorry, uh, from. Yeah, 823 00:34:56.820 --> 00:34:58.340 let me read it. The Planck length can be 824 00:34:58.340 --> 00:35:00.060 defined from three fundamental physical 825 00:35:00.060 --> 00:35:01.900 constants. The speed of light in a vacuum, 826 00:35:02.060 --> 00:35:04.560 the Planck constant. That's something, um, 827 00:35:04.560 --> 00:35:06.900 which physicists are very familiar with. And 828 00:35:06.900 --> 00:35:09.620 the gravitational constant. It's the smallest 829 00:35:09.620 --> 00:35:12.060 distance about which current 830 00:35:12.780 --> 00:35:15.660 experimentally corroborated models of 831 00:35:15.660 --> 00:35:18.460 physics can make meaningful statements. 832 00:35:19.260 --> 00:35:22.140 So what it says is. And I'll go on. At such 833 00:35:22.140 --> 00:35:24.500 small distances, the conventional laws of 834 00:35:24.500 --> 00:35:27.400 macrophysics no longer apply, and even 835 00:35:27.720 --> 00:35:29.680 relativistic physics requires special 836 00:35:29.680 --> 00:35:32.240 treatment. The bottom line is that a Planck 837 00:35:32.240 --> 00:35:35.000 length below that, all bets are off. We 838 00:35:35.000 --> 00:35:37.360 really don't understand what is happening to 839 00:35:37.360 --> 00:35:39.880 the physics. And maybe Andrew's point is well 840 00:35:39.880 --> 00:35:42.760 made that, uh, a Planck length 841 00:35:43.000 --> 00:35:45.960 black hole is actually what you 842 00:35:45.960 --> 00:35:47.750 have at the center of, uh, 843 00:35:48.440 --> 00:35:51.440 constituting a black hole system. Um, I need 844 00:35:51.440 --> 00:35:54.180 to talk to my, uh, expert friends about 845 00:35:54.180 --> 00:35:56.980 this because, um, at this level of 846 00:35:56.980 --> 00:35:59.660 technicality, my knowledge is 847 00:35:59.820 --> 00:36:02.540 not specialist, But I do know people 848 00:36:02.540 --> 00:36:05.260 whose knowledge is far better than mine. 849 00:36:05.340 --> 00:36:08.300 And next time I run into them, uh, I'm going 850 00:36:08.300 --> 00:36:10.820 to ask them exactly about these questions and 851 00:36:10.820 --> 00:36:13.260 hopefully feed back to space nuts and to 852 00:36:13.260 --> 00:36:15.580 Andrew and his, um, fellow listeners. 853 00:36:15.740 --> 00:36:18.620 Andrew Dunkley: Okay, so the question remains open, Andrew. 854 00:36:19.260 --> 00:36:19.660 Professor Fred Watson: Yeah. 855 00:36:19.660 --> 00:36:21.500 Andrew Dunkley: I think we'll give you a definite maybe. 856 00:36:22.470 --> 00:36:23.790 Professor Fred Watson: Maybe it's the answer. Yes. 857 00:36:23.790 --> 00:36:25.550 Andrew Dunkley: All right, thanks, Andrew. Thanks for the 858 00:36:25.550 --> 00:36:27.110 question. Let's move on to a question from 859 00:36:27.110 --> 00:36:29.070 Ulf Petersen in Sweden. 860 00:36:29.070 --> 00:36:31.950 Yeah, uh, alf, I've got some news from you 861 00:36:31.950 --> 00:36:33.830 which you may or may not be aware of, but, 862 00:36:33.830 --> 00:36:36.470 uh, a young lady named Julia Engstrom, 863 00:36:36.550 --> 00:36:39.350 A professional golfer from Sweden, Just 864 00:36:39.350 --> 00:36:42.070 won the new south wales women's open, 865 00:36:42.070 --> 00:36:44.270 which we hosted here in dubbo a couple of 866 00:36:44.270 --> 00:36:44.710 weeks ago. 867 00:36:45.110 --> 00:36:45.510 Professor Fred Watson: Great. 868 00:36:45.510 --> 00:36:48.350 Andrew Dunkley: I. Because our course was closed to play for 869 00:36:48.350 --> 00:36:51.070 members, um, uh, we got to go out there and 870 00:36:51.070 --> 00:36:52.790 watch these young ladies go around. It was a 871 00:36:52.790 --> 00:36:55.770 European tour event. Uh, she won 872 00:36:55.770 --> 00:36:57.770 not only her share of the prize money, but a 873 00:36:57.770 --> 00:36:59.450 two year exemption on the European tour. 874 00:36:59.450 --> 00:37:02.250 She's 18 years old. And she 875 00:37:02.250 --> 00:37:04.730 swings it like a champion. I mean, she was 876 00:37:04.730 --> 00:37:07.250 hitting it 260 to 280 meters, 877 00:37:07.650 --> 00:37:10.010 whaling it past me. And she's just a slip of 878 00:37:10.010 --> 00:37:12.890 a kid, but, uh, remarkable player and 879 00:37:12.890 --> 00:37:14.490 someone to watch out for in the future, if 880 00:37:14.490 --> 00:37:16.610 you're a golfer. Julia Engstrom is her name. 881 00:37:16.690 --> 00:37:19.290 So there you go, Ulf. A little bit of. I can 882 00:37:19.290 --> 00:37:20.770 feel his pride swelling now. 883 00:37:21.480 --> 00:37:24.230 Um, now he says hello, uh, Andrew and 884 00:37:24.230 --> 00:37:26.150 Fred, uh, what a fantastic community you've 885 00:37:26.150 --> 00:37:28.190 started. And it's a global one, too. I've 886 00:37:28.190 --> 00:37:30.310 been a faithful listener of your pods now for 887 00:37:30.310 --> 00:37:32.150 a year and enjoy them very much. Never 888 00:37:32.150 --> 00:37:34.190 imagined Thursdays could be that exciting. 889 00:37:34.750 --> 00:37:36.829 I'd usually say something derogatory, but I'm 890 00:37:36.829 --> 00:37:39.550 feeling good today. Um, don't know if 891 00:37:39.550 --> 00:37:41.590 this question might be of interest to the 892 00:37:41.590 --> 00:37:44.030 show. Is there any chance that it's a black 893 00:37:44.030 --> 00:37:45.950 hole question? By the way, Fred, is there any 894 00:37:45.950 --> 00:37:48.650 chance that a black hole might not exist in 895 00:37:48.650 --> 00:37:51.410 its, uh. Inside its event horizon? After all, 896 00:37:51.410 --> 00:37:53.330 black holes are claimed to be singularities 897 00:37:53.330 --> 00:37:55.650 that is infinitesimal in size. 898 00:37:56.210 --> 00:37:58.730 In practical terms, nothing. Right. Uh, if 899 00:37:58.730 --> 00:38:01.650 so, could an event horizon act as a sort 900 00:38:01.650 --> 00:38:04.170 of a delayed postal service, never 901 00:38:04.170 --> 00:38:06.850 informing anyone outside what has 902 00:38:06.850 --> 00:38:08.930 happened? So, like Australia Post, really? 903 00:38:09.360 --> 00:38:11.850 Um, no, they're great. Actually, uh, there's 904 00:38:11.850 --> 00:38:14.130 another piece of news. Dubbo Post Office 905 00:38:14.940 --> 00:38:17.820 here in town. Got Post Office of the Year. 906 00:38:18.140 --> 00:38:20.100 Professor Fred Watson: Oh, uh, fabulous. That's great, Nick. 907 00:38:20.100 --> 00:38:22.580 Andrew Dunkley: About a month ago. So we're doing it right 908 00:38:22.580 --> 00:38:23.180 here, aren't we? 909 00:38:23.380 --> 00:38:24.820 Professor Fred Watson: Uh, you're doing well in Dubbo. 910 00:38:24.820 --> 00:38:27.660 Andrew Dunkley: Extra questions. Would physics allow matter 911 00:38:27.820 --> 00:38:30.240 still to be pulled into the vent event, uh, 912 00:38:30.459 --> 00:38:33.380 into the horizon, even if the black hole was 913 00:38:33.380 --> 00:38:33.820 gone? 914 00:38:35.420 --> 00:38:37.670 Professor Fred Watson: Great, uh, question, Ulf. And, um, 915 00:38:38.460 --> 00:38:41.450 In. In a sense, the. The, um. He's right 916 00:38:41.450 --> 00:38:44.130 about the event horizon acting as a delayed 917 00:38:44.130 --> 00:38:46.010 postal service because, 918 00:38:47.090 --> 00:38:49.770 um, it stops the transfer of information. 919 00:38:49.930 --> 00:38:52.370 We do know that, uh, black holes can 920 00:38:52.370 --> 00:38:55.290 evaporate courtesy of Hawking radiation. 921 00:38:55.770 --> 00:38:58.650 But, um, basically. And that 922 00:38:58.650 --> 00:39:00.770 involves the transfer of information. We know 923 00:39:00.770 --> 00:39:02.810 that, but it's very, very slow. So 924 00:39:03.610 --> 00:39:06.530 the event horizon does shield the black 925 00:39:06.530 --> 00:39:08.610 hole from the outside world, if I can put it 926 00:39:08.610 --> 00:39:11.540 that way. But, um, in terms of 927 00:39:11.860 --> 00:39:13.860 whether the black hole itself exists, 928 00:39:14.580 --> 00:39:16.620 it's kind of the other way around. The only 929 00:39:16.620 --> 00:39:19.260 way the event horizon can exist is if there 930 00:39:19.260 --> 00:39:21.410 is a black hole at the center. Uh, 931 00:39:22.340 --> 00:39:24.660 in other words, this infinitesimally small 932 00:39:24.740 --> 00:39:26.900 singularity, essentially 933 00:39:27.140 --> 00:39:29.460 distorting space time to the extent that 934 00:39:29.460 --> 00:39:31.420 you've got this shield around it, this black 935 00:39:31.420 --> 00:39:34.300 hole. The black hole. Uh, sorry, the black 936 00:39:34.300 --> 00:39:37.100 hole. Event horizon. The event horizon, in 937 00:39:37.100 --> 00:39:39.560 some ways, Is an illusion, Andrew, because, 938 00:39:40.020 --> 00:39:42.760 um, it's just the point of no return. It's 939 00:39:43.000 --> 00:39:45.160 the thing that won't let light out. And it 940 00:39:45.160 --> 00:39:47.800 certainly is black. We've seen that from the 941 00:39:47.800 --> 00:39:50.680 event horizon image, uh, that was released 942 00:39:50.680 --> 00:39:53.320 last year. But, uh, without the black 943 00:39:53.320 --> 00:39:56.280 hole, the event horizon doesn't exist. So, 944 00:39:56.580 --> 00:39:59.160 uh, there has to be this 945 00:39:59.160 --> 00:40:01.400 singularity at the middle with all its 946 00:40:01.640 --> 00:40:04.640 complicated, uh, infinitesimally small 947 00:40:04.640 --> 00:40:06.920 planck length dimensions that we've just been 948 00:40:07.320 --> 00:40:10.310 discussing. Um, yeah, great question though, 949 00:40:10.310 --> 00:40:12.350 and thank you very much. And yes, Sweden 950 00:40:12.350 --> 00:40:13.990 rocks. I was there not very long ago. 951 00:40:14.070 --> 00:40:16.030 Andrew Dunkley: And as monty python says, nothing can come 952 00:40:16.030 --> 00:40:19.030 from nothing. Can't be nothing. 953 00:40:20.150 --> 00:40:20.880 Professor Fred Watson: Yes, yes. 954 00:40:20.880 --> 00:40:23.110 Andrew Dunkley: Um, thanks, alf. Appreciate the question. 955 00:40:23.670 --> 00:40:26.110 One more thing before we finish up, fred, and 956 00:40:26.110 --> 00:40:28.630 this is, um, a little bit of, um, an add on 957 00:40:28.630 --> 00:40:30.550 from a question about the roche limit. A 958 00:40:30.550 --> 00:40:32.030 couple of weeks ago, we were trying to figure 959 00:40:32.030 --> 00:40:34.390 out the roche limit between 960 00:40:35.110 --> 00:40:36.990 the earth and the moon. And as you explained, 961 00:40:36.990 --> 00:40:39.460 the roche limit is the point where gravity, 962 00:40:39.460 --> 00:40:42.270 uh, will destroy one of the 963 00:40:42.270 --> 00:40:45.230 objects involved, um, uh, in 964 00:40:45.230 --> 00:40:47.630 the, uh, situation. So, um, you could 965 00:40:47.630 --> 00:40:49.230 probably explain it better than I just did. 966 00:40:49.230 --> 00:40:52.110 But, um, uh, basically we were trying 967 00:40:52.110 --> 00:40:54.470 to figure out how close the moon could get to 968 00:40:54.470 --> 00:40:57.030 the earth before it was obliterated. Yeah, 969 00:40:57.430 --> 00:40:59.470 life on earth would probably be obliterated 970 00:40:59.470 --> 00:40:59.750 too. 971 00:40:59.750 --> 00:41:01.550 Professor Fred Watson: Well, that's right. It would be a tricky 972 00:41:01.550 --> 00:41:03.930 situation for all of us. But it is. It's much 973 00:41:03.930 --> 00:41:06.450 less than I thought it would be, Andrew. 974 00:41:06.790 --> 00:41:08.850 Um, the roche limit for the moon is 975 00:41:08.850 --> 00:41:11.570 9,492 kilometers. 976 00:41:11.730 --> 00:41:13.490 And I think that's from the center of the 977 00:41:13.490 --> 00:41:16.070 earth. So it's actually 3,004, uh, 978 00:41:16.370 --> 00:41:19.210 114 kilometers above the surface. Imagine 979 00:41:19.210 --> 00:41:21.650 the moon 3,000 kilometers above the surface. 980 00:41:21.650 --> 00:41:22.130 Whoa. 981 00:41:22.130 --> 00:41:23.250 Andrew Dunkley: Wouldn't it look amazing? 982 00:41:23.490 --> 00:41:25.290 Professor Fred Watson: It would look pretty amazing. That's right. 983 00:41:25.290 --> 00:41:27.490 Andrew Dunkley: Just for a few moments until we all died of 984 00:41:27.490 --> 00:41:28.370 fire or die. 985 00:41:28.370 --> 00:41:31.060 Professor Fred Watson: I guess that's right. Yeah. 986 00:41:31.060 --> 00:41:32.860 Andrew Dunkley: But that's okay. We'd have plenty of toilet 987 00:41:32.860 --> 00:41:33.220 paper. 988 00:41:33.540 --> 00:41:35.540 Professor Fred Watson: Ah, ah, we would. We'd be all right. Yes. 989 00:41:35.940 --> 00:41:37.940 Andrew Dunkley: So three, uh, so 9,000. 990 00:41:39.540 --> 00:41:42.420 Professor Fred Watson: Yeah, 9,492 kilometers 991 00:41:42.500 --> 00:41:43.660 from the center of the earth. 992 00:41:43.660 --> 00:41:45.900 Andrew Dunkley: Close as it could get before it was destroyed 993 00:41:45.900 --> 00:41:48.700 by our gravity. And we would go down with the 994 00:41:48.700 --> 00:41:49.060 ship. 995 00:41:49.940 --> 00:41:51.220 Professor Fred Watson: Absolutely. Yeah. 996 00:41:51.220 --> 00:41:53.020 Andrew Dunkley: In a nutshell. All right, now we've got that 997 00:41:53.020 --> 00:41:55.340 sorted out. Uh, thank you, Fred, so much. 998 00:41:55.340 --> 00:41:56.260 It's always a pleasure. 999 00:41:57.310 --> 00:41:58.790 Professor Fred Watson: It's always a pleasure talking to you too, 1000 00:41:58.790 --> 00:42:00.590 Andrew. And we'll speak again soon, I hope. 1001 00:42:00.590 --> 00:42:02.750 Andrew Dunkley: You will indeed. And thank you for, uh, 1002 00:42:02.750 --> 00:42:04.350 listening. Thank you for your contributions. 1003 00:42:04.430 --> 00:42:06.350 Keep them coming. We love to hear from you, 1004 00:42:06.350 --> 00:42:08.430 whether it's on social media or via our 1005 00:42:08.430 --> 00:42:10.870 website where you can send us emails. Uh, we 1006 00:42:10.870 --> 00:42:12.870 have a little contact form there, so you can 1007 00:42:12.870 --> 00:42:15.590 send us questions and, uh, to the 1008 00:42:15.590 --> 00:42:17.670 patrons. There'll be some bonus material 1009 00:42:17.670 --> 00:42:20.190 coming up real soon. Uh, other than that, 1010 00:42:20.270 --> 00:42:22.670 thank you and we'll see you again next time 1011 00:42:22.670 --> 00:42:25.110 on another edition of the Space Nuts 1012 00:42:25.110 --> 00:42:27.900 Podcast, Space Notes. You'll be this 1013 00:42:28.060 --> 00:42:29.900 to the SpaceNuts Podcast, 1014 00:42:31.420 --> 00:42:33.980 available in Apple Podcasts, Google 1015 00:42:33.980 --> 00:42:35.580 Podcasts, Spotify, 1016 00:42:35.820 --> 00:42:38.580 iHeartRadio, or your favorite podcast 1017 00:42:38.580 --> 00:42:41.020 player. You can also stream on demand@ah, 1018 00:42:41.180 --> 00:42:41.900 bytes.com. 1019 00:42:42.300 --> 00:42:44.380 Professor Fred Watson: This has been another quality podcast 1020 00:42:44.380 --> 00:42:46.460 production from Thights.com.