บทถอดความฉบับเต็มของ Antimatter Achievement: Scientists Successfully Trap Positrons for Months

properties, physicists should be 42 00:01:59.420 --> 00:02:01.500 able to put this fundamental symmetry to its 43 00:02:01.500 --> 00:02:04.280 most stringent test yet. And if the 44 00:02:04.280 --> 00:02:06.520 measurements don't match up as expected, that 45 00:02:06.520 --> 00:02:08.920 would reveal a crack in the standard model of 46 00:02:08.920 --> 00:02:11.360 particle physics, offering new clues to 47 00:02:11.360 --> 00:02:13.840 enduring mysteries, including why ordinary 48 00:02:13.840 --> 00:02:16.120 matter, rather than antimatter, dominates the 49 00:02:16.120 --> 00:02:19.120 universe. After first capturing the 50 00:02:19.120 --> 00:02:21.440 fast moving particle from radioactive decay, 51 00:02:21.440 --> 00:02:23.600 the authors cooled it to nearly absolute 52 00:02:23.600 --> 00:02:26.440 zero. They then suspended the particle in a 53 00:02:26.440 --> 00:02:28.360 near perfect vacuum, preventing it from 54 00:02:28.360 --> 00:02:30.560 touching ordinary matter, an encounter which 55 00:02:30.560 --> 00:02:33.310 would cause it to annihilate. By trapping and 56 00:02:33.310 --> 00:02:35.670 cooling a positron in this way, the authors 57 00:02:35.670 --> 00:02:38.070 created what they're calling a 1 positron, 58 00:02:38.070 --> 00:02:40.910 quantum cyclotron. In this state, the 59 00:02:40.910 --> 00:02:43.070 positron essentially behaves very much like 60 00:02:43.070 --> 00:02:45.230 an artificial atom with quantum energy 61 00:02:45.230 --> 00:02:47.390 levels, scientists can precisely control and 62 00:02:47.390 --> 00:02:50.350 observe. The study's lead author, 63 00:02:50.350 --> 00:02:52.390 Gerald Gabriels from Northwestern University, 64 00:02:52.790 --> 00:02:55.070 says, if you take an electron and a positron 65 00:02:55.070 --> 00:02:56.630 and collide them together, they'll both 66 00:02:56.630 --> 00:02:59.260 disappear. They'll annihilate each other. And 67 00:02:59.260 --> 00:03:01.260 he says the big mystery of the universe is 68 00:03:01.260 --> 00:03:03.060 the fact that the Big Bang should have 69 00:03:03.060 --> 00:03:04.820 created equal amounts of matter and 70 00:03:04.820 --> 00:03:06.940 antimatter. But if that were true, it would 71 00:03:06.940 --> 00:03:09.300 annihilate and we'd be left with nothing. So 72 00:03:09.300 --> 00:03:10.940 clearly there's something wrong with the 73 00:03:10.940 --> 00:03:12.900 theory, and that's what science is trying to 74 00:03:12.900 --> 00:03:15.740 figure out. The standard model of 75 00:03:15.740 --> 00:03:17.740 particle physics is a long standing 76 00:03:17.740 --> 00:03:19.940 hypothesis describing the fundamental 77 00:03:19.940 --> 00:03:21.980 particles and three of the four fundamental 78 00:03:21.980 --> 00:03:24.300 forces, the electromagnetic force, the strong 79 00:03:24.300 --> 00:03:26.100 nuclear force and the weight weak nuclear 80 00:03:26.100 --> 00:03:29.020 force. Experiment after experiment 81 00:03:29.020 --> 00:03:31.140 has confirmed the model's predictions with 82 00:03:31.140 --> 00:03:33.980 extraordinary precision. Yet physicists 83 00:03:33.980 --> 00:03:36.020 know the model is not complete. It doesn't 84 00:03:36.020 --> 00:03:38.900 explain dark energy or dark matter. Nor can 85 00:03:38.900 --> 00:03:41.020 it explain why the observable universe 86 00:03:41.020 --> 00:03:43.420 contains overwhelmingly more matter than 87 00:03:43.420 --> 00:03:46.380 antimatter. Gabriel says 88 00:03:46.380 --> 00:03:48.580 science knows the standard model has to be 89 00:03:48.580 --> 00:03:50.620 wrong somewhere, or at least incomplete. 90 00:03:51.190 --> 00:03:53.070 Nearly everything on Earth is made of just 91 00:03:53.070 --> 00:03:55.590 three familiar particles electrons, 92 00:03:55.590 --> 00:03:58.190 protons, neutrons. And an 93 00:03:58.190 --> 00:04:00.550 antimatter universe instead could be built 94 00:04:00.550 --> 00:04:02.030 from their antimatter counterparts, 95 00:04:02.030 --> 00:04:04.070 positrons, antiprotons and 96 00:04:04.070 --> 00:04:06.670 antineutrons. Gabriel says the 97 00:04:06.670 --> 00:04:08.910 simple fact is, if everything on Earth were 98 00:04:08.910 --> 00:04:10.910 antimatter, it would be difficult to tell the 99 00:04:10.910 --> 00:04:13.830 difference. The fireworks only occur 100 00:04:13.830 --> 00:04:16.230 when the two worlds, matter and antimatter, 101 00:04:16.230 --> 00:04:18.900 meet. Now, one of the problems with testing 102 00:04:18.900 --> 00:04:20.940 all this is that scientists can't simply put 103 00:04:20.940 --> 00:04:23.380 a positron into a conventional container. 104 00:04:23.620 --> 00:04:25.660 That's because touching the container itself, 105 00:04:25.660 --> 00:04:27.260 which is normal matter, would cause the 106 00:04:27.260 --> 00:04:30.020 antimatter particle to annihilate. So if 107 00:04:30.020 --> 00:04:31.980 scientists want to study antimatter, they 108 00:04:31.980 --> 00:04:34.940 need to handle it really carefully. So to 109 00:04:34.940 --> 00:04:36.860 carefully handle the particle, the authors 110 00:04:36.860 --> 00:04:39.180 used a state of the art trap, which combines 111 00:04:39.180 --> 00:04:41.420 specialised electric and magnetic fields in 112 00:04:41.420 --> 00:04:43.860 order to suspend the positron in a void. 113 00:04:44.670 --> 00:04:46.790 Sitting in the middle of this container, the 114 00:04:46.790 --> 00:04:49.590 positron never touches anything. And because 115 00:04:49.590 --> 00:04:51.190 of this setup, uh, the positron in 116 00:04:51.190 --> 00:04:53.350 Gabrielle's laboratory has remained trapped 117 00:04:53.350 --> 00:04:56.230 for months. Mind you, catching the positron 118 00:04:56.230 --> 00:04:58.110 in the first place was its own challenge. 119 00:04:58.510 --> 00:05:00.990 Positrons can be generated during radioactive 120 00:05:00.990 --> 00:05:03.910 decay of certain atomic nuclei. In 121 00:05:03.910 --> 00:05:06.350 this experiment, Gabriels used nuclei from 122

00:05:06.350 --> 00:05:09.350 Sodium 22, a rare radioactive isotope 123 00:05:09.350 --> 00:05:11.990 of sodium. When the particles emerge from the 124 00:05:11.990 --> 00:05:14.150 nuclei, they carry enormous amounts of 125 00:05:14.150 --> 00:05:16.950 energy. So the team first needed to slow down 126 00:05:16.950 --> 00:05:19.030 the positron and then guide it into the 127 00:05:19.030 --> 00:05:21.870 trap's near perfect vacuum. The interior of 128 00:05:21.870 --> 00:05:24.870 the trap is cooled to just 0.3 degrees above 129 00:05:24.870 --> 00:05:26.870 absolute zero, which is minus 130 00:05:26.870 --> 00:05:29.790 273.15 degrees Celsius. 131 00:05:30.270 --> 00:05:32.710 Gabriels and colleagues also demonstrated 132 00:05:32.710 --> 00:05:34.550 that they could precisely manipulate and 133 00:05:34.550 --> 00:05:36.750 detect the positron's individual quantum 134 00:05:36.750 --> 00:05:39.650 energy states. By delivering carefully 135 00:05:39.650 --> 00:05:42.410 tuned microwaves, they added tiny precise 136 00:05:42.410 --> 00:05:44.610 amounts of energy to the positron and 137 00:05:44.610 --> 00:05:46.810 detected its resulting quantum transitions. 138 00:05:47.530 --> 00:05:49.810 And that level of control is essential for 139 00:05:49.810 --> 00:05:52.050 scientists ultimate goal, measuring the 140 00:05:52.050 --> 00:05:53.809 positron's magnetic properties with 141 00:05:53.809 --> 00:05:56.010 extraordinary precision and then comparing 142 00:05:56.010 --> 00:05:58.970 them with those of an electron. In 143 00:05:58.970 --> 00:06:01.370 previous work, Gabriels used a 1 electron 144 00:06:01.370 --> 00:06:03.730 quantum cyclotron to measure the electron's 145 00:06:03.730 --> 00:06:05.930 magnetic moment to about 1 part in 10 146 00:06:05.930 --> 00:06:07.850 trillion, which is among the most precise 147 00:06:07.850 --> 00:06:09.760 measurements ever made for any electron 148 00:06:09.830 --> 00:06:10.870 elementary particle. 149 00:06:11.830 --> 00:06:14.150 Now with the trapped antimatter, Ghebrios 150 00:06:14.150 --> 00:06:15.950 plans to make the same kind of quantum 151 00:06:15.950 --> 00:06:18.230 measurement with the positron and then put 152 00:06:18.230 --> 00:06:21.070 the two results head to head. He says current 153 00:06:21.070 --> 00:06:22.950 theory suggests there should be no difference 154 00:06:22.950 --> 00:06:25.710 between the two measurements, but if it turns 155 00:06:25.710 --> 00:06:27.790 out they're not equal, that would be the 156 00:06:27.790 --> 00:06:30.070 biggest discovery in physics in the last 157 00:06:30.070 --> 00:06:32.910 century. And needless to say, we'll keep 158 00:06:32.910 --> 00:06:35.910 you informed. This is 159 00:06:35.910 --> 00:06:38.590 space time still to come. 160 00:06:38.830 --> 00:06:41.070 Liftoff for Japan's first sample return 161 00:06:41.150 --> 00:06:43.670 mission to the red planet. Mars and the Time 162 00:06:43.670 --> 00:06:46.270 Lords have demanded a change

in how science 163 00:06:46.270 --> 00:06:49.030 understands time. All that and more 164 00:06:49.030 --> 00:06:51.310 still to come on, uh, space time. 165 00:07:05.320 --> 00:07:08.280 Japan's Martian Moons exploration MMX 166 00:07:08.280 --> 00:07:10.960 mission is now on its way to the Red Planet's 167 00:07:10.960 --> 00:07:13.160 moon Phobos. Following its successful launch 168 00:07:13.160 --> 00:07:15.440 from the Tanegashima Space Centre, a thousand 169 00:07:15.440 --> 00:07:17.080 kilometres south of Tokyo, 170 00:07:27.000 --> 00:07:29.560 Tim Mendham: We have a successful rest of our H3 launch 171 00:07:29.560 --> 00:07:32.120 vehicle from number 10 with the MMX first 172 00:07:32.120 --> 00:07:33.520 custom board from Jackset. 173 00:07:33.520 --> 00:07:36.460 Stuart Gary: And 4.5 ton spacecraft 174 00:07:36.460 --> 00:07:38.900 will arrive at Mars in August next year, 175 00:07:39.060 --> 00:07:41.260 spending several years orbiting the 27 176 00:07:41.260 --> 00:07:43.100 kilometre wide potato shaped moon, 177 00:07:43.100 --> 00:07:45.220 undertaking readings and searching for 178 00:07:45.220 --> 00:07:47.380 appropriate landing sites. In 179 00:07:47.380 --> 00:07:49.780 2029, it'll deploy a small 180 00:07:49.780 --> 00:07:52.580 25 kilogramme four wheeled Land Rover called 181 00:07:52.580 --> 00:07:55.460 Itafix, which will descend down to the Phobos 182 00:07:55.460 --> 00:07:57.060 surface and undertake preliminary 183 00:07:57.060 --> 00:07:59.900 observations before MMX itself drops 184 00:07:59.900 --> 00:08:01.740 down at the surface, undertaking several 185 00:08:01.740 --> 00:08:04.460 touchdowns in 2030, collecting up to 10 186 00:08:04.460 --> 00:08:07.130 grammes of samples. These will then be 187 00:08:07.130 --> 00:08:09.610 loaded onto a return module which will fly 188 00:08:09.610 --> 00:08:12.570 back to Earth in 2031, parachuting down into 189 00:08:12.570 --> 00:08:14.810 the Woomera rocket range in Outback South 190 00:08:14.810 --> 00:08:17.090 Australia for collection by scientists. 191 00:08:17.810 --> 00:08:20.290 Dr. Sarah Webb from Swinburne University 192 00:08:20.610 --> 00:08:22.650 says those samples will help answer key 193 00:08:22.650 --> 00:08:25.090 questions about the origins of both Martian 194 00:08:25.090 --> 00:08:26.770 moons, Phobos and Deimos. 195 00:08:27.170 --> 00:08:29.330 They're either captured asteroids from the 196 00:08:29.330 --> 00:08:31.530 nearby main asteroid belt between Mars and 197 00:08:31.530 --> 00:08:33.970 Jupiter, or they're the remains of debris 198 00:08:33.970 --> 00:08:35.890 ejector, uh, thrown out into orbit following 199 00:08:35.890 --> 00:08:38.320 a giant asteroid impact under the Martian 200 00:08:38.320 --> 00:08:38.920 surface. 201 00:08:39.080 --> 00:08:40.920 Silvia Mantovanini : So this mission, called Martian Moons 202 00:08:40.920 --> 00:08:43.560 Exploration, or MMX for short, is 203 00:08:43.640 --> 00:08:45.880 quite exciting. It's led by

the Japanese 204 00:08:45.880 --> 00:08:48.120 space agency, and its whole goal is not only 205 00:08:48.120 --> 00:08:50.960 to go to Mars to orbit around Phobos, but you 206 00:08:50.960 --> 00:08:53.040 actually collect a sample of it and return it 207 00:08:53.040 --> 00:08:55.200 back to Earth. Uh, and if successful, this 208 00:08:55.200 --> 00:08:57.440 will be the first time ever that a sample has 209 00:08:57.440 --> 00:08:59.640 been collected from the Martian planet system 210 00:08:59.640 --> 00:09:01.400 and then brought back to Earth for further 211 00:09:01.480 --> 00:09:03.880 analysis. So us scientists are, uh, uh, 212 00:09:03.880 --> 00:09:05.880 shaking in our boots, getting really excited 213 00:09:05.880 --> 00:09:07.120 because this is things that we've been 214 00:09:07.120 --> 00:09:09.240 waiting for for decades and it's now within 215 00:09:09.940 --> 00:09:12.060 Stuart Gary: critics are going to say it's Phobos, it's 216 00:09:12.060 --> 00:09:14.860 not Mars. The Moon was chosen because it's 217 00:09:14.860 --> 00:09:16.980 easier to land there, it's easy to take off. 218 00:09:17.380 --> 00:09:19.820 Silvia Mantovanini : Much easier. And we don't know what Phobos is 219 00:09:19.820 --> 00:09:21.940 as well. We theorise that it's likely a 220 00:09:21.940 --> 00:09:23.660 captured asteroid, but there's also a theory 221 00:09:23.660 --> 00:09:25.940 that it is the leftover chunk of Mars that 222 00:09:25.940 --> 00:09:28.580 formed because of a giant impact. And so 223 00:09:28.980 --> 00:09:30.780 we won't actually know until we get our hands 224 00:09:30.780 --> 00:09:32.780 on that material and be able to analyse it in 225 00:09:32.780 --> 00:09:33.220 more detail. 226 00:09:33.300 --> 00:09:34.860 Stuart Gary: That's one of the first things you learn in 227 00:09:34.860 --> 00:09:37.500 astronomy school. Is Phobos a chunk of Mars 228 00:09:37.500 --> 00:09:40.160 that been blasted into orbit, or is it a 229 00:09:40.160 --> 00:09:41.120 captured asteroid? 230 00:09:41.440 --> 00:09:43.880 Silvia Mantovanini : Right. It's a mystery that hopefully by 231 00:09:43.880 --> 00:09:46.880 2035, once we have the sample back on Earth, 232 00:09:46.880 --> 00:09:48.060 we might be able to answer. 233 00:09:48.060 --> 00:09:49.920 Uh, and then that has a lot of rundown 234 00:09:49.920 --> 00:09:52.240 consequences for what we understand about our 235 00:09:52.240 --> 00:09:54.520 solar system as well. Because Mars is the 236 00:09:54.520 --> 00:09:56.600 only other rocky planet aside from Earth, 237 00:09:56.600 --> 00:09:58.400 that has moons. But its moons are, uh, 238 00:09:58.440 --> 00:10:01.040 obviously very different to our own gigantic, 239 00:10:01.040 --> 00:10:03.080 very influential moon that we have here on 240 00:10:03.080 --> 00:10:03.360 Earth. 241 00:10:03.360 --> 00:10:05.160 Stuart Gary: Yeah, we got our moon thanks to the giant 242 00:10:05.160 --> 00:10:07.680 impact we did. Mars, on the other hand,

is 243 00:10:07.750 --> 00:10:09.750 the only place in the universe that we know 244 00:10:09.750 --> 00:10:11.910 of, other than Earth, where there's a real 245 00:10:11.990 --> 00:10:14.990 likelihood, a real potential for life to have 246 00:10:14.990 --> 00:10:17.630 existed. It was once warm and wet, and as it 247 00:10:17.630 --> 00:10:20.070 cooled, it lost its protective shielding, its 248 00:10:20.070 --> 00:10:22.950 atmosphere. And, uh, the water that was there 249 00:10:23.110 --> 00:10:25.830 slowly evaporated and degassed into space. 250 00:10:26.070 --> 00:10:28.110 Any life now would be fossilised, and there 251 00:10:28.110 --> 00:10:30.430 are tantalising signs of that in places like 252 00:10:30.430 --> 00:10:31.430 Chiava Falls. 253 00:10:31.430 --> 00:10:34.230 Silvia Mantovanini : I think it is, it is exceptionally exciting. 254 00:10:34.230 --> 00:10:36.070 As you said, Mars has launched a very 255 00:10:36.070 --> 00:10:37.990 different planet, very similar to Earth in a 256 00:10:37.990 --> 00:10:40.030 lot of ways. And if life did exist there, 257 00:10:40.030 --> 00:10:42.190 those fossils should remain in the fossil 258 00:10:42.190 --> 00:10:44.390 record. And so I think that's one of the 259 00:10:44.390 --> 00:10:46.870 biggest questions we have just in general as 260 00:10:46.870 --> 00:10:49.790 humans, as beings is are we alone in the 261 00:10:49.790 --> 00:10:51.830 universe? Is life only on the Earth, or are 262 00:10:51.830 --> 00:10:53.590 we going to find it elsewhere. And the first 263 00:10:53.590 --> 00:10:55.710 place to really dig into that is our own 264 00:10:55.710 --> 00:10:57.950 solar system. We've got some tantalising 265 00:10:57.950 --> 00:10:58.390 candidates. 266 00:10:58.390 --> 00:11:00.350 We know that we've got moons around Jupiter 267 00:11:00.350 --> 00:11:02.870 and Saturn that likely have big subsurface 268 00:11:02.870 --> 00:11:05.070 oceans that could have life in them, but 269 00:11:05.070 --> 00:11:07.430 they're very far away. They're less tangible 270 00:11:07.430 --> 00:11:09.390 to us to physically think about going and 271 00:11:09.390 --> 00:11:11.970 collecting samples analysed. Where is Mars? 272 00:11:12.130 --> 00:11:14.330 Mars is right there. Yes, it's far away, but 273 00:11:14.330 --> 00:11:16.170 it's fairly close to the Earth. We can get 274 00:11:16.170 --> 00:11:18.050 there within a year or two. We can collect a 275 00:11:18.050 --> 00:11:19.530 sample and bring it back in less than a 276 00:11:19.530 --> 00:11:22.010 decade. But it is that kind of holy grail of 277 00:11:22.010 --> 00:11:24.090 can we answer this question with one simple 278 00:11:24.090 --> 00:11:24.530 sample? 279 00:11:24.610 --> 00:11:26.730 Stuart Gary: And it's easier to launch off because it's so 280 00:11:26.730 --> 00:11:27.410 much smaller. 281 00:11:27.970 --> 00:11:30.570 Silvia Mantovanini : That's right. Gravity is, um, relentless. 282 00:11:30.570 --> 00:11:32.890 Unfortunately, in the universe all things 283 00:11:32.890 --> 00:11:34.690 fall at the whim of gravity. And so if you 284 00:11:34.690 --> 00:11:36.450 have a smaller mass, a smaller planet or a 285 00:11:36.450 --> 00:11:38.810 small moon, how wonderful you are able to get 286 00:11:38.810 --> 00:11:41.050 that exit velocity. You need to get on your 287 00:11:41.050 --> 00:11:42.590 merry way. Whereas launching, launching 288 00:11:42.590 --> 00:11:44.510 things from, uh, Earth is very doable. We've 289 00:11:44.510 --> 00:11:46.710 done it for decades now. But it is 290 00:11:46.710 --> 00:11:48.870 extraordinarily expensive to fight against 291 00:11:48.870 --> 00:11:51.150 that force of gravity and get things into 292 00:11:51.150 --> 00:11:53.230 orbit and away from the Earth as we need to. 293 00:11:53.390 --> 00:11:55.750 Stuart Gary: China are likely to undertake their sample 294 00:11:55.750 --> 00:11:58.750 return mission to Mars and, um, return 295 00:11:58.750 --> 00:12:01.390 those samples possibly by 2029. 296 00:12:01.550 --> 00:12:04.190 That's, that's very exciting. The American 297 00:12:04.350 --> 00:12:06.910 European mission, which was the final 298 00:12:06.990 --> 00:12:09.960 stage of what the Mars perseverance robe 299 00:12:09.960 --> 00:12:11.440 is doing on Jezero Crater. 300 00:12:11.440 --> 00:12:13.640 Now that's sort of up in the air at the 301 00:12:13.640 --> 00:12:15.480 moment. No, uh, pun intended because of 302 00:12:15.480 --> 00:12:17.800 federal funding, but nevertheless, it's got 303 00:12:17.800 --> 00:12:19.400 the samples, they're lying there on the 304 00:12:19.400 --> 00:12:21.640 surface to be collected. We just have to go 305 00:12:21.640 --> 00:12:23.240 back there and get them. It's a very 306 00:12:23.240 --> 00:12:26.000 interesting stage in research right now. It 307 00:12:26.000 --> 00:12:27.960 must be really frustrating as a, as a 308 00:12:27.960 --> 00:12:29.920 scientist involved in this type of research, 309 00:12:30.400 --> 00:12:33.320 to see one of your goals so near and 310 00:12:33.320 --> 00:12:35.200 yet out of reach so far. 311 00:12:35.200 --> 00:12:37.890 Silvia Mantovanini : I think it is a very, uh, 312 00:12:37.890 --> 00:12:40.640 unique time in history where we know so much 313 00:12:40.640 --> 00:12:43.400 and so little and we know what we need to do 314 00:12:43.400 --> 00:12:45.320 to be able to advance technologies. And yet 315 00:12:45.320 --> 00:12:47.720 we're constantly blocked by same challenges 316 00:12:47.720 --> 00:12:49.650 by, by different challenges that, that are, 317 00:12:49.650 --> 00:12:52.120 uh, global at this point. But certainly when 318 00:12:52.120 --> 00:12:54.040 we're looking to the United States that 319 00:12:54.040 --> 00:12:56.240 there's been a large halt on what we thought 320 00:12:56.240 --> 00:12:58.040 the direction of science is going to be in 321 00:12:58.040 --> 00:13:00.960 the next 10, 20 years. And so as a scientist 322

00:13:01.040 --> 00:13:03.300 worldwide, look, we've got this collective 323 00:13:03.300 --> 00:13:05.780 worry of we know what we need to do for 324 00:13:05.780 --> 00:13:07.740 advancing human knowledges not just in 325 00:13:07.740 --> 00:13:09.540 astronomy or space exploration, but in 326 00:13:09.540 --> 00:13:11.420 medicine and things that are really going to 327 00:13:11.420 --> 00:13:13.940 change our life. And yet we're halted by 328 00:13:13.940 --> 00:13:14.500 funding. 329 00:13:14.500 --> 00:13:16.380 And I think this is a universal problem and 330 00:13:16.380 --> 00:13:18.180 something that here in Australia a lot of 331 00:13:18.180 --> 00:13:19.940 scientists have been quite vocal about with 332 00:13:19.940 --> 00:13:22.500 our Academy of Science trying to advocate to 333 00:13:22.500 --> 00:13:25.020 all of the MPs around our country how 334 00:13:25.020 --> 00:13:27.500 vital scientific research is for our everyday 335 00:13:27.500 --> 00:13:29.060 life and how it should be funded 336 00:13:29.060 --> 00:13:31.470 significantly because we only know that good 337 00:13:31.470 --> 00:13:33.750 consequences will come when we, when we put 338 00:13:33.750 --> 00:13:34.350 in that money. 339 00:13:34.430 --> 00:13:36.670 Stuart Gary: Yeah, the loss of funding for the European 340 00:13:36.670 --> 00:13:38.950 Southern Observatory project we were involved 341 00:13:38.950 --> 00:13:41.950 in, that's a, uh, that is such a low. That is 342 00:13:41.950 --> 00:13:42.670 devastating. 343 00:13:42.830 --> 00:13:45.230 Silvia Mantovanini : It is devastating. And Australia has this 344 00:13:45.230 --> 00:13:48.110 phenomenal history, especially in astronomy 345 00:13:48.110 --> 00:13:50.830 where we fat way above our weight 346 00:13:50.910 --> 00:13:52.790 in terms of the global scale. And with the 347 00:13:52.790 --> 00:13:54.550 European Southern Observatory, it was not 348 00:13:54.550 --> 00:13:56.270 only for the astrophysics and the 349 00:13:56.270 --> 00:13:57.830 observations of it all, it was actually for 350 00:13:57.830 --> 00:13:59.710 the instrumentation as well, which Australia 351 00:13:59.710 --> 00:14:02.210 is a world leader at. And so the community 352 00:14:02.210 --> 00:14:04.450 right now and is speaking from, coming from 353 00:14:04.450 --> 00:14:06.450 that, that astronomical community is trying 354 00:14:06.450 --> 00:14:09.450 to figure out what is, what is next for us, 355 00:14:09.450 --> 00:14:12.130 where can we maybe have different access to 356 00:14:12.130 --> 00:14:14.290 different telescopes to help support the 357 00:14:14.290 --> 00:14:16.570 goals to keep Australia on top and all those 358 00:14:16.570 --> 00:14:18.290 trickle down technologies that come from it, 359 00:14:18.290 --> 00:14:20.330 all the instrumentation that ends up going 360 00:14:20.330 --> 00:14:22.930 into other sectors or those algorithms and 361 00:14:22.930 --> 00:14:25.170 those skills for people that we train that 362

00:14:25.170 --> 00:14:27.210 end up going into other sectors, all within 363 00:14:27.210 --> 00:14:29.930 the Australian economy. So it is a, it's a 364 00:14:29.930 --> 00:14:32.370 very um, an interesting challenge and one 365 00:14:32.370 --> 00:14:34.250 that we were keen to solve. 366 00:14:34.250 --> 00:14:37.250 Stuart Gary: I keep thinking of the ligo, uh, experience 367 00:14:37.490 --> 00:14:40.170 that we had a few years ago where LIGO 368 00:14:40.170 --> 00:14:42.850 offered Australia a gravitational wave 369 00:14:42.850 --> 00:14:45.050 detector. It was there, it was waiting, the 370 00:14:45.050 --> 00:14:47.010 plans were there and the Australian 371 00:14:47.010 --> 00:14:48.690 government said no. 372 00:14:49.250 --> 00:14:51.370 So it went to India and India still haven't 373 00:14:51.370 --> 00:14:52.370 built it unfortunately. 374 00:14:52.530 --> 00:14:54.810 Silvia Mantovanini : Yes, it is, it is Google. I think what's so 375 00:14:54.810 --> 00:14:57.410 challenging is in a funding uh, limited 376 00:14:57.790 --> 00:14:59.550 environment where you've got more people 377 00:15:00.030 --> 00:15:02.630 fighting to do good work and all work in the 378 00:15:02.630 --> 00:15:04.630 scientific community across Australia is good 379 00:15:04.630 --> 00:15:06.710 and worthy work and it's very difficult. You 380 00:15:06.710 --> 00:15:08.710 can't, it's very, very difficult to say this 381 00:15:08.710 --> 00:15:10.630 is more deserving of this or this or that. 382 00:15:10.630 --> 00:15:13.270 And it is an extremely difficult landscape. 383 00:15:13.270 --> 00:15:15.190 And I think one way to solve that is to have 384 00:15:15.190 --> 00:15:17.950 a landscape that has more funding with bigger 385 00:15:17.950 --> 00:15:20.350 dedicated visions. So specific funding for 386 00:15:20.350 --> 00:15:23.310 specific goals that is able uh, to help 387 00:15:23.310 --> 00:15:24.350 serve those communities. 388 00:15:24.590 --> 00:15:26.950 Stuart Gary: That's uh, Dr. Sarah Webb from Swinburne 389 00:15:26.950 --> 00:15:29.860 University. Um, and this is space time 390 00:15:30.500 --> 00:15:33.420 still to come. The Time Lords demand a change 391 00:15:33.420 --> 00:15:36.260 in how we understand time itself. And later 392 00:15:36.260 --> 00:15:38.500 in the Science report, a, ah, world first 393 00:15:38.500 --> 00:15:41.020 Australian developed personalised MRNA 394 00:15:41.020 --> 00:15:43.700 melanoma, um, vaccine. All that and more 395 00:15:43.700 --> 00:15:45.940 still to come on space time. 396 00:15:53.390 --> 00:15:53.710 Silvia Mantovanini : Foreign, 397 00:16:02.390 --> 00:16:05.310 Stuart Gary: Uh, following a decision 398 00:16:05.390 --> 00:16:08.390 to abolish the leap second leap seconds 399 00:16:08.390 --> 00:16:10.550 are added or deducted every few years in 400 00:16:10.550 --> 00:16:12.510 order to keep the world's atomic clocks 401 00:16:12.510 --> 00:16:14.430 aligned with the actual rotation of our 402 00:16:14.430 --> 00:16:16.550 planet, so that seasons start where they're 403 00:16:16.550 --> 00:16:18.510 supposed to, computers perform as they 404 00:16:18.510 --> 00:16:21.030 should, and satellite navigation systems work 405 00:16:21.030 --> 00:16:23.950 correctly. The world's clocks are 406 00:16:23.950 --> 00:16:26.510 governed by their seconds, 60 of them in 407 00:16:26.510 --> 00:16:29.310 every minute, 3,600 in every hour, 408 00:16:29.310 --> 00:16:32.230 and 86,400 in a standard 409 00:16:32.230 --> 00:16:35.110 mean solar day. By the way, a standard 410 00:16:35.110 --> 00:16:37.669 mean solar day is the time it takes the Earth 411 00:16:37.669 --> 00:16:40.150 to complete one full rotation, placing any 412 00:16:40.150 --> 00:16:42.430 given spot with the sun at zenith, that is 413 00:16:42.430 --> 00:16:44.830 directly overhead, directly back at zenith, 414 00:16:44.830 --> 00:16:47.720 one full planetary rotation later. That's 415 00:16:47.720 --> 00:16:49.960 very different to a sidereal day, which is 416 00:16:49.960 --> 00:16:52.120 used by astronomers and observatories to 417 00:16:52.120 --> 00:16:54.440 track the Earth's rotation, as referenced by 418 00:16:54.440 --> 00:16:56.350 a bunch of fixed, seemingly unmoving, um, 419 00:16:56.840 --> 00:16:59.640 background stars. The sidereal day 420 00:16:59.640 --> 00:17:01.880 shows that the Earth's day is actually just a 421 00:17:01.880 --> 00:17:02.760 little bit shorter. 422 00:17:02.760 --> 00:17:05.520 23 hours, 56 minutes and 4 seconds. 423 00:17:05.520 --> 00:17:05.880 That's 424 00:17:05.880 --> 00:17:08.600 86164.09 425 00:17:08.600 --> 00:17:11.400 seconds of mean solar time. That 426 00:17:11.400 --> 00:17:13.480 difference happens because as the Earth spins 427 00:17:13.480 --> 00:17:15.880 on its axis, it's also moving along its 428 00:17:15.880 --> 00:17:18.690 orbital path around the sun. So to bring the 429 00:17:18.690 --> 00:17:20.970 sun back to the exact same overhead position, 430 00:17:20.970 --> 00:17:23.850 the Earth needs to rotate not 360 degrees, 431 00:17:23.850 --> 00:17:26.770 but actually 361 degrees. That takes 432 00:17:26.770 --> 00:17:28.490 an extra four minutes. Hence the time 433 00:17:28.490 --> 00:17:31.290 difference. Measuring the exact 434 00:17:31.290 --> 00:17:33.930 time on Earth nowadays is achieved by a 435 00:17:33.930 --> 00:17:36.410 global system of atomic clocks, collectively 436 00:17:36.490 --> 00:17:38.890 known as Coordinated Universal Time, or 437 00:17:38.890 --> 00:17:41.370 UTC Zulu. If you're in the military, 438 00:17:41.930 --> 00:17:44.690 it's the gold standard. It never changes for 439 00:17:44.690 --> 00:17:46.970 daylight saving or for regional differences. 440 00:17:47.930 --> 00:17:50.850 So 1200 UTC in London is the same as 441 00:17:50.850 --> 00:17:53.730 1200 UTC in Sydney or in Tokyo or 442 00:17:53.730 --> 00:17:55.370 Washington, or even aboard the International 443 00:17:55.530 --> 00:17:56.330

Space Station. 444 00:17:56.810 --> 00:17:59.330 Originally, every town and village kept its 445 00:17:59.330 --> 00:18:02.250 own local time. Basically, 12 noon 446 00:18:02.250 --> 00:18:04.370 was when the sun was directly overhead in 447 00:18:04.370 --> 00:18:06.850 your local village. But the arrival of the 448 00:18:06.850 --> 00:18:09.170 railways in the 1800s forced countries to 449 00:18:09.170 --> 00:18:11.450 introduce standard time zones so trains 450 00:18:11.450 --> 00:18:13.660 wouldn't crash into each other. And with the 451 00:18:13.660 --> 00:18:15.820 arrival of standard time zones across the 452 00:18:15.820 --> 00:18:17.900 globe, navigation became easier and 453 00:18:17.900 --> 00:18:20.020 businesses flowed more smoothly. It was a 454 00:18:20.020 --> 00:18:22.540 great idea. But with the arrival of the 455 00:18:22.540 --> 00:18:25.020 computer age in spaceflight, accuracy has 456 00:18:25.020 --> 00:18:27.460 become of prime importance. You see, 457 00:18:27.460 --> 00:18:30.220 precision counts. The Earth's 458 00:18:30.220 --> 00:18:32.780 rotation tends to wobble and gradually slow 459 00:18:32.780 --> 00:18:34.740 down. It's due to tidal friction and 460 00:18:34.740 --> 00:18:37.340 geological events like earthquakes. It makes 461 00:18:37.340 --> 00:18:40.020 the planet's rotation an unreliable standard 462 00:18:40.020 --> 00:18:42.540 for modern science, navigation and Internet 463 00:18:42.540 --> 00:18:43.060 systems. 464 00:18:43.850 --> 00:18:45.610 So as clocks needed to become more and more 465 00:18:45.610 --> 00:18:47.450 accurate, scientists moved away from 466 00:18:47.450 --> 00:18:49.530 traditional mechanical and electrical devices 467 00:18:49.610 --> 00:18:52.170 and began relying ever more on advanced 468 00:18:52.170 --> 00:18:55.170 atomic clocks. In 1967, the 469 00:18:55.170 --> 00:18:57.090 governing body of the International Bureau of 470 00:18:57.090 --> 00:18:59.010 Weights and Measures, which standardises the 471 00:18:59.010 --> 00:19:01.250 ward's measurements, adopted a more precise 472 00:19:01.250 --> 00:19:03.330 definition of second based on the 473 00:19:03.330 --> 00:19:06.130 measurements of cesium atoms. And this is 474 00:19:06.130 --> 00:19:08.730 what underpins coordinated universal time. 475 00:19:09.400 --> 00:19:12.080 Atomic clocks use cesium fountains to track 476 00:19:12.080 --> 00:19:15.080 time with extreme accuracy. Cesium gas 477 00:19:15.080 --> 00:19:17.000 is cooled down to near absolute zero 478 00:19:19.480 --> 00:19:21.680 and then pushed up as a fountain through a 479 00:19:21.680 --> 00:19:24.480 microwave filled cavity. The microwaves are 480 00:19:24.480 --> 00:19:26.680 adjusted until they match the exact natural 481 00:19:26.680 --> 00:19:28.840 resonance frequency of the cesium atoms, 482 00:19:28.840 --> 00:19:30.880 allowing the clock to count the fixed number 483 00:19:30.880 --> 00:19:33.840 of cycles that define a second. This method 484 00:19:33.840 --> 00:19:36.600 is so exact that cesium clocks neither 485 00:19:36.600 --> 00:19:39.260 gain nor lose a single second in, in tens of 486 00:19:39.260 --> 00:19:41.900 millions of years. And this level of 487 00:19:41.900 --> 00:19:43.740 precision has allowed the second to be 488 00:19:43.740 --> 00:19:44.700 measured by counting 489 00:19:44.700 --> 00:19:49.460 9,192,631,770 490 00:19:49.460 --> 00:19:51.980 oscillations or radiation cycles of a 491 00:19:51.980 --> 00:19:54.180 Cesium 133 atom during its 492 00:19:54.180 --> 00:19:56.540 unperturbed ground state. Hyper defined 493 00:19:56.540 --> 00:19:59.420 transition. But the precision of atomic 494 00:19:59.420 --> 00:20:01.100 clocks have their own problems because they 495 00:20:01.100 --> 00:20:03.220 pick up changes in the variability of the 496 00:20:03.220 --> 00:20:05.910 Earth's rate of rotation. And that's where 497 00:20:05.910 --> 00:20:07.710 leap seconds come in. Since their 498 00:20:07.710 --> 00:20:10.430 introduction in 1972, leap seconds have been 499 00:20:10.430 --> 00:20:13.110 added to our clocks on 27 occasions, most 500 00:20:13.110 --> 00:20:15.750 recently at the end of New Year's Eve 2016. 501 00:20:16.550 --> 00:20:18.990 The additional leap seconds keep atomic 502 00:20:18.990 --> 00:20:21.510 clocks accurate, navigation systems precise, 503 00:20:21.670 --> 00:20:24.270 moving transport smoothly, or at least trying 504 00:20:24.270 --> 00:20:26.790 to, and coordinating everything from big 505 00:20:26.790 --> 00:20:28.870 business transactions to the automated 506 00:20:28.870 --> 00:20:31.580 docking of spacecraft in orbit. Even when the 507 00:20:31.580 --> 00:20:33.580 power output needs to be increased during ad 508 00:20:33.580 --> 00:20:36.420 breaks and televised football games. These 509 00:20:36.420 --> 00:20:39.100 changes, by adding leap seconds, compensates 510 00:20:39.100 --> 00:20:41.340 for the known variabilities in the rotational 511 00:20:41.340 --> 00:20:43.020 speed of, uh, the planet's axis. 512 00:20:43.660 --> 00:20:46.140 Without them, time would slowly drift away 513 00:20:46.300 --> 00:20:48.860 out of coordination and into ever increasing 514 00:20:48.860 --> 00:20:51.660 confusion. But the real need for 515 00:20:51.660 --> 00:20:53.940 leap seconds came when scientists determined 516 00:20:53.940 --> 00:20:56.220 that the Earth's axial rotation rate simply 517 00:20:56.220 --> 00:20:59.210 wasn't consistent enough. See, the Earth's 518 00:20:59.210 --> 00:21:01.610 axial rotation changes due to things like 519 00:21:01.610 --> 00:21:04.170 mass redistribution and torque forces acting 520 00:21:04.170 --> 00:21:06.570 on the planet. While we think of the Earth as 521 00:21:06.570 --> 00:21:08.690 a rigid cue ball, it's actually a very 522 00:21:08.690 --> 00:21:10.890 dynamic, slightly squashed sphere with a 523 00:21:10.890 --> 00:21:13.330 molten core, fluid oceans, a, uh, shifting 524 00:21:13.330 -->

00:21:15.730 atmosphere and moving tectonic plates. 525 00:21:16.290 --> 00:21:18.850 Any event that shifts mass closer or further 526 00:21:18.850 --> 00:21:21.130 from the Earth's rotational axis changes the 527 00:21:21.130 --> 00:21:23.290 planet's axial spin. That's due to the 528 00:21:23.290 --> 00:21:25.610 conservation of angular momentum, much like a 529 00:21:25.610 --> 00:21:28.090 spinning figure skater pulls their arms in to 530 00:21:28.090 --> 00:21:31.000 spin faster. Overall, there's a long term 531 00:21:31.000 --> 00:21:33.080 slowdown of the planet's spin rate over 532 00:21:33.080 --> 00:21:35.680 centuries and millennia. That's caused by 533 00:21:35.680 --> 00:21:37.760 gravitational tidal friction with the Moon 534 00:21:37.760 --> 00:21:40.440 and to a lesser extent, the Sun. See, the 535 00:21:40.440 --> 00:21:42.640 Moon's gravity pulls on the Earth's oceans, 536 00:21:42.720 --> 00:21:45.600 creating tidal bulges. And because Earth 537 00:21:45.600 --> 00:21:47.880 rotates faster than the Moon orbits it, the 538 00:21:47.880 --> 00:21:50.360 Earth tries to drag its watery bulge ahead of 539 00:21:50.360 --> 00:21:53.240 the Moon. This causes the Moon's gravity to 540 00:21:53.240 --> 00:21:55.320 act like a sort of brake, pulling back on 541 00:21:55.320 --> 00:21:57.480 this bulge, steadily draining the Earth's 542 00:21:57.480 --> 00:21:59.480 rotational energy, which causes the Earth's 543 00:21:59.480 --> 00:22:02.380 day to lengthen by 2.3 milliseconds every 544 00:22:02.380 --> 00:22:04.980 century. And it doesn't end there. There are 545 00:22:04.980 --> 00:22:06.860 other factors influencing the Earth's axial 546 00:22:06.860 --> 00:22:09.260 spin as well, including the climate. And the 547 00:22:09.260 --> 00:22:11.540 last ice age, which physically covered the 548 00:22:11.540 --> 00:22:13.500 planet in a thick heavy sheet of ice, 549 00:22:13.500 --> 00:22:16.380 altering the shape of the Earth. Post glacial 550 00:22:16.380 --> 00:22:18.060 rebound following the melting of those 551 00:22:18.060 --> 00:22:20.620 billions of tons of ice cover has slowly seen 552 00:22:20.620 --> 00:22:22.900 the distribution of mass shift relative to 553 00:22:22.900 --> 00:22:24.220 the planet's centre of gravity. 554 00:22:24.780 --> 00:22:26.980 During the last ice age, heavy glaciers 555 00:22:26.980 --> 00:22:29.350 flattened the, uh, Earth's poles. Now that 556 00:22:29.350 --> 00:22:31.390 most of that ice has melted, the land at the 557 00:22:31.390 --> 00:22:33.870 poles is slowly bouncing back upwards, making 558 00:22:33.870 --> 00:22:36.310 the planet more spherical. And this is 559 00:22:36.310 --> 00:22:39.190 shifting mass closer to the axis, speeding up 560 00:22:39.190 --> 00:22:41.910 the planet's rotation. There are also modern 561 00:22:41.910 --> 00:22:43.710 changes, such as the rapid melting of 562 00:22:43.710 --> 00:22:46.190 glaciers in Greenland and Antarctica, which 563 00:22:46.190 --> 00:22:47.990 is dumping water back into the oceans, 564 00:22:48.150 --> 00:22:50.150 redistributing mass towards the equator, 565 00:22:50.710 --> 00:22:52.630 again acting like that figure skater 566 00:22:52.710 --> 00:22:54.950 extending their arms to slow down rotation. 567 00:22:55.640 --> 00:22:57.640 The Earth's spin also changes dynamically 568 00:22:57.640 --> 00:22:59.960 from day to day and season to season because 569 00:22:59.960 --> 00:23:02.000 of the weather. With wind patterns and strong 570 00:23:02.000 --> 00:23:04.520 global wind systems like jet streams pushing 571 00:23:04.520 --> 00:23:06.040 hard against the Earth's, uh, surface 572 00:23:06.040 --> 00:23:08.840 topography like mountain ranges. When 573 00:23:08.840 --> 00:23:10.520 strong winds blow in the direction of the 574 00:23:10.520 --> 00:23:12.560 Earth's rotation, the atmosphere gains 575 00:23:12.560 --> 00:23:15.120 angular momentum, causing the solid Earth to 576 00:23:15.120 --> 00:23:18.040 slow down slightly to compensate. This causes 577 00:23:18.040 --> 00:23:20.240 seasonal variations of up to a millisecond 578 00:23:20.240 --> 00:23:23.180 per day. And internal planetary mechanics 579 00:23:23.180 --> 00:23:25.940 also play an important role. Forces 580 00:23:26.020 --> 00:23:28.340 deep within the planet and sudden tectonic 581 00:23:28.340 --> 00:23:30.060 movements such as earthquakes cause 582 00:23:30.060 --> 00:23:32.500 unpredictable changes deep inside the Earth. 583 00:23:32.900 --> 00:23:34.940 A, uh, primary cause is the drag along the 584 00:23:34.940 --> 00:23:36.980 core mantle boundary layer. The Earth's 585 00:23:36.980 --> 00:23:39.460 molten iron outer core sloshes around 586 00:23:39.460 --> 00:23:41.660 independently of the base of the rocky mantle 587 00:23:41.660 --> 00:23:44.380 layer above it. Changes in magnetic fields 588 00:23:44.380 --> 00:23:46.140 and fluid currents at the core mantle 589 00:23:46.140 --> 00:23:48.460 boundary can also cause the crust to speed up 590 00:23:48.460 --> 00:23:51.170 or slow down. Over decades. And then there 591 00:23:51.170 --> 00:23:53.530 are mega earthquakes like, uh, the 2004 592 00:23:53.530 --> 00:23:56.210 Indian Ocean tsunami or the 2011 Japanese 593 00:23:56.210 --> 00:23:58.530 earthquake, which instantly shift billions of 594 00:23:58.530 --> 00:24:00.890 tons of mass, enough to permanently speed up 595 00:24:00.890 --> 00:24:03.370 rotation, shortening the day by about 1.8 596 00:24:03.370 --> 00:24:06.250 microseconds. And all these events are making 597 00:24:06.250 --> 00:24:08.770 timekeeping in the space age increasingly 598 00:24:08.770 --> 00:24:11.570 less and less accurate. And so in 599 00:24:11.570 --> 00:24:14.490 1972, scientists introduced the leap 600 00:24:14.490 --> 00:24:16.850 second, a, uh, one second adjustment added to 601 00:24:16.850 --> 00:24:19.130 coordinated universal time to keep highly 602 00:24:19.130 --> 00:24:21.450 precise atomic clocks

synchronised to the 603 00:24:21.450 --> 00:24:23.430 Earth's natural, natural irregular rotation. 604 00:24:24.070 --> 00:24:26.430 Because the planet's rotation fluctuates and 605 00:24:26.430 --> 00:24:28.750 gradually slows down over long periods, a 606 00:24:28.750 --> 00:24:30.790 discrepancy slowly builds between 607 00:24:30.870 --> 00:24:33.190 astronomical time and atomic time. 608 00:24:33.750 --> 00:24:36.470 When the gap approaches 0.9 seconds, a leap 609 00:24:36.470 --> 00:24:38.830 second is inserted, making the final minute 610 00:24:38.830 --> 00:24:41.590 of that day 61 seconds long, counted as 611 00:24:41.590 --> 00:24:44.350 23, 59 and 60 seconds, usually on New 612 00:24:44.350 --> 00:24:47.230 Year's Eve. But while leap seconds 613 00:24:47.230 --> 00:24:49.470 keep clocks aligned with space, they're an 614 00:24:49.470 --> 00:24:51.390 operational nightmare for modern day digital 615 00:24:51.390 --> 00:24:53.830 infrastructure, causing systems to regularly 616 00:24:54.050 --> 00:24:56.010 crash and giving computer programme software 617 00:24:56.010 --> 00:24:58.770 writers still recovering from the Y2K bug 618 00:24:58.770 --> 00:25:01.610 connections. And the next big leap second 619 00:25:01.610 --> 00:25:03.970 insertion will be a negative event, removing 620 00:25:03.970 --> 00:25:06.250 a second from the clock. The need for a 621 00:25:06.250 --> 00:25:08.570 negative leap second is due to changes in the 622 00:25:08.570 --> 00:25:10.370 Earth's core, which has actually caused the 623 00:25:10.370 --> 00:25:13.130 planet to temporarily speed up. And this 624 00:25:13.130 --> 00:25:15.130 raised fears that scientists would have to 625 00:25:15.130 --> 00:25:17.890 implement a negative leap second, a 59 second 626 00:25:17.890 --> 00:25:20.330 minute. And that's going to send software 627 00:25:20.330 --> 00:25:22.530 engineers into uncontrollable nervous 628 00:25:22.530 --> 00:25:24.650 breakdowns. Few will survive without their 629 00:25:24.650 --> 00:25:25.330 teddy bears. 630 00:25:25.970 --> 00:25:27.890 Now, global tech companies have warned that 631 00:25:27.890 --> 00:25:30.170 software infrastructure is entirely untested 632 00:25:30.170 --> 00:25:32.770 for deleting a second. That's created a 633 00:25:32.770 --> 00:25:35.570 massive risk of severe, widespread digital 634 00:25:35.650 --> 00:25:38.050 breakdowns. Again, think Y2K. 635 00:25:38.690 --> 00:25:40.970 So to eliminate these risks, delegates from 636 00:25:40.970 --> 00:25:43.370 69 countries at the International Bureau of 637 00:25:43.370 --> 00:25:45.730 Weights and Measures meeting back in 2022 638 00:25:45.810 --> 00:25:48.770 voted to remove leap seconds by 2035 639 00:25:48.930 --> 00:25:51.130 and start discussing a different method of 640 00:25:51.130 --> 00:25:52.980 keeping the Earth's days intact. Sync with 641 00:25:52.980 --> 00:25:55.860 the astronomical world. But the urgent need 642 00:25:55.860 --> 00:25:58.020 to introduce a negative leap second has 643 00:25:58.020 --> 00:25:59.900 forced the group to vote again last week, 644 00:25:59.900 --> 00:26:01.580 this time to bring the abolishment of the 645 00:26:01.580 --> 00:26:04.301 leap second forward to 20 May 646 00:26:04.432 --> 00:26:07.260 2027. Under the new rules, 647 00:26:07.340 --> 00:26:09.980 rather than micromanaging a one second gap, 648 00:26:09.980 --> 00:26:12.220 the allowed drift between atomic time and the 649 00:26:12.220 --> 00:26:14.460 Earth's rotation will be expanded to a full 650 00:26:14.460 --> 00:26:17.020 hour. Clocks will continuously run without 651 00:26:17.020 --> 00:26:19.970 interruption. Over centuries, our time 652 00:26:19.970 --> 00:26:21.970 will slowly drift out of alignment with the 653 00:26:21.970 --> 00:26:24.730 sun. And eventually, like in thousands of 654 00:26:24.730 --> 00:26:26.930 years from now, future generations will 655 00:26:26.930 --> 00:26:29.770 simply implement a single leap hour, treating 656 00:26:29.770 --> 00:26:31.970 it much like a predictable daylight savings 657 00:26:31.970 --> 00:26:34.690 time shift. This is space time. 658 00:26:43.580 --> 00:26:43.820 Silvia Mantovanini : Foreign. 659 00:26:50.940 --> 00:26:52.220 Stuart Gary: Take a brief look at some of the other 660 00:26:52.220 --> 00:26:54.460 stories making news in Science this week with 661 00:26:54.460 --> 00:26:57.380 a Science report. Scientists have announced a 662 00:26:57.380 --> 00:26:59.460 major breakthrough in skin cancer treatment 663 00:26:59.460 --> 00:27:01.660 with a world first Australian developed 664 00:27:01.660 --> 00:27:04.220 personalised M mRNA melanoma vaccine. 665 00:27:04.780 --> 00:27:07.420 Clinical trials of over 1100 patients 666 00:27:07.420 --> 00:27:09.660 showed that adding intysmarin to the standard 667 00:27:09.660 --> 00:27:11.860 post surgery treatment reduced the risk of 668 00:27:11.860 --> 00:27:14.180 melanoma returning within two years by at 669 00:27:14.180 --> 00:27:17.120 least 42%. 82% of 670 00:27:17.120 --> 00:27:19.160 people in the trial's vaccine group were 671 00:27:19.160 --> 00:27:20.840 still living without a recurrence of their 672 00:27:20.840 --> 00:27:23.720 cancer after two years, compared to 70% on 673 00:27:23.720 --> 00:27:26.400 the standard keytruda treatment alone. The 674 00:27:26.400 --> 00:27:28.800 trial is continuing in order to track longer 675 00:27:28.800 --> 00:27:31.760 term outcomes. A new 676 00:27:31.760 --> 00:27:34.400 study has shown a catastrophic collapse of 677 00:27:34.400 --> 00:27:36.480 environment and marine life in the wake of 678 00:27:36.480 --> 00:27:39.200 the 2010 BP Deepwater Horizon oil 679 00:27:39.200 --> 00:27:41.600 spill. The findings, reported in the 680 00:27:41.600 --> 00:27:42.960 Proceedings of the National Academy of 681 00:27:42.960 --> 00:27:45.880 Sciences, found that populations of 682 00:27:45.880 --> 00:27:48.540 deep water fishes, crustaceans and squid 683 00:27:48.540

--> 00:27:51.220 declined significantly over the past 16 years 684 00:27:51.300 --> 00:27:54.060 since the BP ecological disaster first 685 00:27:54.060 --> 00:27:56.580 unfolded. The study included over 686 00:27:56.580 --> 00:27:59.340 2,000 net samples, acoustic surveys and 687 00:27:59.340 --> 00:28:01.820 genetic analyses. It revealed 688 00:28:01.820 --> 00:28:04.660 declines in 64% of fish numbers, 689 00:28:04.740 --> 00:28:07.220 62% of large crustaceans and 690 00:28:07.220 --> 00:28:10.100 60% in small squid and other cephalopods. 691 00:28:10.420 --> 00:28:12.420 And some of the most ecologically important 692 00:28:12.420 --> 00:28:13.900 animals were hit even harder. 693 00:28:14.210 --> 00:28:16.850 Krill declined by 83%, lantern 694 00:28:16.850 --> 00:28:19.770 fishes by 63% and Bristol mouth fishes 695 00:28:19.770 --> 00:28:22.650 by 69%. These concentrations 696 00:28:22.650 --> 00:28:25.210 are essential for whales, dolphins, tuna, 697 00:28:25.210 --> 00:28:27.010 sharks, seabirds and other marine life. 698 00:28:27.490 --> 00:28:30.450 Aquatic life that was common back in 2011 has 699 00:28:30.450 --> 00:28:33.130 now virtually disappeared. BP's 700 00:28:33.130 --> 00:28:35.410 Deepwater Horizon oil spill released between 701 00:28:35.410 --> 00:28:38.290 4 and 4.9 million barrels of oil, while 702 00:28:38.290 --> 00:28:41.010 approximately 770,000 gallons of chemical 703 00:28:41.010 --> 00:28:43.290 dispersant were injected nearly the wellhead. 704 00:28:43.530 --> 00:28:45.570 All related compounds have since been 705 00:28:45.570 --> 00:28:47.450 detected in deep water fish eggs and 706 00:28:47.450 --> 00:28:49.850 encephalopod tissues. It's an 707 00:28:49.850 --> 00:28:52.530 environmental disaster on an unprecedented 708 00:28:52.530 --> 00:28:55.170 scale. Breakdown 709 00:28:55.170 --> 00:28:57.470 plastics such as polyurethane in chew foam, 710 00:28:57.470 --> 00:28:59.970 uh, kitchen sponges and mattresses can be a 711 00:28:59.970 --> 00:29:02.490 problem for recycling now. 712 00:29:02.490 --> 00:29:04.650 Scientists have improved an enzyme normally 713 00:29:04.650 --> 00:29:06.770 produced by bacteria found in compost to 714 00:29:06.770 --> 00:29:08.730 enable it to more efficiently break down 715 00:29:08.730 --> 00:29:11.490 polyurethane main products. Researchers 716 00:29:11.490 --> 00:29:13.970 edited the DNA of the bacteria to produce a 717 00:29:13.970 --> 00:29:16.250 more efficient version of a plastic eating 718 00:29:16.250 --> 00:29:19.210 enzyme. They tested the enzyme on pieces of 719 00:29:19.210 --> 00:29:21.730 soles of shoes, and after three days it had 720 00:29:21.730 --> 00:29:24.330 chewed up about 1.4% of the polyurethane, 721 00:29:24.410 --> 00:29:26.370 splitting the waste product into smaller, 722 00:29:26.370 --> 00:29:27.370 reusable pieces. 723 00:29:28.010 --> 00:29:30.530 A report in the journal ChemCatalyst claims 724 00:29:30.530 --> 00:29:32.370 that although their research is still in its 725 00:29:32.370 --> 00:29:35.130 early stages, it does show Promise for future 726 00:29:35.130 --> 00:29:36.570 plastic reprocessing. 727 00:29:38.250 --> 00:29:40.330 A new study has found that people who spend 728 00:29:40.330 --> 00:29:42.730 more time with their pet cats tend to have 729 00:29:42.730 --> 00:29:45.610 more positive moods. The findings reported 730 00:29:45.610 --> 00:29:47.730 in the journal Eye Science are based on a 731 00:29:47.730 --> 00:29:50.250 trial involving 29 cats and their human 732 00:29:50.250 --> 00:29:53.130 companions. The authors conducted hormonal 733 00:29:53.130 --> 00:29:55.370 analysis through urine samples, attached 734 00:29:55.370 --> 00:29:57.450 small Bluetooth low energy beacons to the 735 00:29:57.450 --> 00:29:59.530 cat's collars to measure their physical daily 736 00:29:59.530 --> 00:30:01.810 proximity, assess the owner's mood through 737 00:30:01.810 --> 00:30:03.810 questionnaires and observe the cat's 738 00:30:03.810 --> 00:30:05.970 behaviour towards their owners and towards 739 00:30:05.970 --> 00:30:08.890 unfamiliar people. The findings revealed 740 00:30:08.890 --> 00:30:11.010 a hormonal connection between cats and their 741 00:30:11.010 --> 00:30:13.330 humans involving oxytocin and cortisol, 742 00:30:13.410 --> 00:30:15.330 hormones that are associated with social 743 00:30:15.330 --> 00:30:17.980 relationships and stress. They showed a uh, 744 00:30:18.090 --> 00:30:20.170 positive correlation in concentrations of 745 00:30:20.170 --> 00:30:22.610 oxytocin for both the cats and their people, 746 00:30:22.690 --> 00:30:25.210 with higher oxytocin levels in cats linked to 747 00:30:25.210 --> 00:30:27.290 lower cortisol levels and fewer negative 748 00:30:27.290 --> 00:30:29.770 feelings in their owners. Ultimately, the 749 00:30:29.770 --> 00:30:31.930 authors observed that positive mood states in 750 00:30:31.930 --> 00:30:33.770 the owners were not connected to how long 751 00:30:33.770 --> 00:30:35.850 they've had their cats, but rather to the 752 00:30:35.850 --> 00:30:38.390 overall physical proximity between owners and 753 00:30:38.390 --> 00:30:40.910 their pets. In other words, owners positive 754 00:30:40.910 --> 00:30:43.310 feelings seem to be most strongly associated 755 00:30:43.310 --> 00:30:45.910 with how much time they spend with their cats 756 00:30:45.910 --> 00:30:48.870 in everyday life. A 757 00:30:48.870 --> 00:30:51.230 new documentary has been released exposing 758 00:30:51.230 --> 00:30:53.750 the famous Patterson Gimlin Bigfoot film as a 759 00:30:53.750 --> 00:30:56.670 fake. The iconic shaky 59 second 760 00:30:56.670 --> 00:30:59.270 silent 16 millimetre clip shows what appears 761 00:30:59.270 --> 00:31:01.910 to be an enormous female Sasquatch walking 762 00:31:01.910 --> 00:31:04.340 along a trail at Bluff Creek, California. 763 00:31:05.050 --> 00:31:07.130 Sceptics have long claimed it's just some 764 00:31:07.130 -->

00:31:09.930 dude in a gorilla costume. And in 2002 765 00:31:09.930 --> 00:31:11.850 Philip Morris, who runs a North Carolina 766 00:31:11.850 --> 00:31:13.930 based company offering costumes, props and 767 00:31:13.930 --> 00:31:15.890 stage products, claimed that he made the 768 00:31:15.890 --> 00:31:17.730 gorilla costume that was used in the film, 769 00:31:17.730 --> 00:31:19.730 but had been reluctant to expose the hoax 770 00:31:19.730 --> 00:31:21.690 earlier for fear of harming his business. 771 00:31:22.250 --> 00:31:24.570 Meanwhile, a few years earlier in 1999, 772 00:31:24.810 --> 00:31:27.010 longtime Patterson and Gimlin friend Bob 773 00:31:27.010 --> 00:31:29.130 Harronius admitted that he was the figure 774 00:31:29.130 --> 00:31:31.900 wearing the costume in the film. He says he 775 00:31:31.900 --> 00:31:33.660 had not gone public earlier because he was 776 00:31:33.660 --> 00:31:35.700 afraid of being convicted of fraud for his 777 00:31:35.700 --> 00:31:37.700 part in the hoax, but agreed to finally go 778 00:31:37.700 --> 00:31:40.500 public following legal advice. The sceptics 779 00:31:40.500 --> 00:31:42.740 Tim Mendham says the new film Capturing 780 00:31:42.740 --> 00:31:45.380 Bigfoot which exposes the hoax has just been 781 00:31:45.380 --> 00:31:46.420 released on cable. 782 00:31:46.420 --> 00:31:47.660 Tim Mendham: The footage is probably one of the most 783 00:31:47.660 --> 00:31:50.020 famous film videos of a cryptid, an unknown 784 00:31:50.020 --> 00:31:51.940 creature, especially a legendary one. And 785 00:31:51.940 --> 00:31:54.660 this is the one taken in 67 in a place called 786 00:31:54.660 --> 00:31:57.540 Bluff Creek in California by two. 787 00:31:57.620 --> 00:31:59.220 I don't know exactly what they were actually 788 00:31:59.220 --> 00:32:01.060 adventurous documentary makers who knows 789 00:32:01.060 --> 00:32:03.000 happened to have a 16 mil camera them and 790 00:32:03.000 --> 00:32:05.840 they filmed a Bigfoot, a Sasquatch, a tall 791 00:32:05.840 --> 00:32:07.800 creature, hairy creature, walking along near 792 00:32:07.800 --> 00:32:10.560 a creek, sort of a stony tree background. 793 00:32:10.640 --> 00:32:13.160 It walks along, it looks at them sort of 794 00:32:13.160 --> 00:32:15.000 strolling, it's not exactly running anywhere, 795 00:32:15.000 --> 00:32:16.960 and then walks on and disappears. And the 796 00:32:16.960 --> 00:32:19.200 film runs for about almost a minute and 797 00:32:19.200 --> 00:32:21.280 became sort of proof for a lot of people that 798 00:32:21.280 --> 00:32:23.480 Bigfoot exists. Now, people have always been 799 00:32:23.480 --> 00:32:26.120 investigating it. You get Hollywood makeup 800 00:32:26.120 --> 00:32:28.240 people trying to see if the costume is real. 801 00:32:28.240 --> 00:32:30.080 There is a costume and the suggestion always 802 00:32:30.080 --> 00:32:32.080 has been, is that the fake footage, it's 803 00:32:32.240 --> 00:32:34.080 quite reasonable. It's probably one of the 804 00:32:34.080 --> 00:32:36.280 clearest bits of footage of such a creature. 805 00:32:36.280 --> 00:32:37.440 And it goes for a long time. 806 00:32:37.440 --> 00:32:39.120 So it's not a fleeting thing disappearing 807 00:32:39.120 --> 00:32:41.960 behind a tree. But since then, a filmmaker 808 00:32:41.960 --> 00:32:43.680 has made this documentary. Uh, recently this 809 00:32:43.680 --> 00:32:46.240 appeared Mark Evans called Capturing Bigfoot. 810 00:32:46.240 --> 00:32:49.240 And it contains a 40 second clip from 811 00:32:49.240 --> 00:32:52.080 a year earlier from 1966, of 812 00:32:52.160 --> 00:32:54.720 Bigfoot walking being filmed in much the same 813 00:32:54.720 --> 00:32:57.440 way, which they're saying is a trial run 814 00:32:57.440 --> 00:33:00.270 for the later 1966 famous clip. 815 00:33:00.270 --> 00:33:02.790 They've also spoken with a gentleman who said 816 00:33:02.790 --> 00:33:04.670 he was actually inside the costume. It's a 817 00:33:04.670 --> 00:33:06.750 lot older now, and that he's playing what 818 00:33:06.750 --> 00:33:09.430 happened to how it was set up. And a son or a 819 00:33:09.430 --> 00:33:11.470 grandson or something like that of the one of 820 00:33:11.470 --> 00:33:13.110 the Patterson or Gimlin, one of the two guys 821 00:33:13.110 --> 00:33:15.350 who made the film, witnessing their relative 822 00:33:15.350 --> 00:33:18.150 burning the costume in the backyard. So it's 823 00:33:18.150 --> 00:33:20.110 a, uh, it was always a controversial film. It 824 00:33:20.110 --> 00:33:22.470 was quite a nice film to look at. It probably 825 00:33:22.470 --> 00:33:24.190 convinced a lot of people there's been a lot 826 00:33:24.190 --> 00:33:25.990 of problems with it. Everything from how the 827 00:33:25.990 --> 00:33:27.910 animal moves, the shape of the animal. Does 828 00:33:27.910 --> 00:33:29.750 it have breasts? Does it not have breasts? 829 00:33:29.750 --> 00:33:31.690 Male, female, etc. The way it sort of just 830 00:33:31.690 --> 00:33:33.650 saunters across the landscape, gives a look 831 00:33:33.650 --> 00:33:35.410 to the researchers, very unlike most 832 00:33:35.410 --> 00:33:37.410 Sasquatch stories you've ever heard and 833 00:33:37.410 --> 00:33:39.570 trying to get a better grip on it. So this 834 00:33:39.570 --> 00:33:42.090 film contains probably evidence which is as 835 00:33:42.090 --> 00:33:45.050 definitive as the original Patterson Gimlin 836 00:33:45.050 --> 00:33:47.570 film. So you think, uh, all right, okay, 837 00:33:47.570 --> 00:33:49.930 which one is real? So now there's some firmer 838 00:33:49.930 --> 00:33:52.290 quotes evident in quotes that the original 839 00:33:52.290 --> 00:33:54.370 film is not true. Not that anyone who 840 00:33:54.370 --> 00:33:56.570 seriously investigates cryptids really does 841 00:33:56.570 --> 00:33:57.850 think it's true. But I'm sure there are 842 00:33:57.850 --> 00:33:59.530 people who still do.

Charlie Z People 843 00:33:59.530 --> 00:34:01.530 involved. Patterson. Patterson died not long 844 00:34:01.530 --> 00:34:04.070 after in 72. It's interesting that this new 845 00:34:04.070 --> 00:34:06.110 evidence has cropped up pretty much saying we 846 00:34:06.110 --> 00:34:08.150 have the silver bullet that proves that the 847 00:34:08.150 --> 00:34:09.990 original film was not true. What a shame, 848 00:34:10.310 --> 00:34:10.710 really. 849 00:34:10.790 --> 00:34:11.950 It'd be nice if it was true. 850 00:34:11.950 --> 00:34:14.950 Stuart Gary: I mean we all want Bigfoot to be real, but. 851 00:34:14.950 --> 00:34:16.550 Tim Mendham: Yeah, but you gotta have the evidence. 852 00:34:16.630 --> 00:34:19.590 Stuart Gary: You need a corpse or the DNA evidence 853 00:34:19.590 --> 00:34:20.470 at least that's never. 854 00:34:20.470 --> 00:34:21.830 Tim Mendham: But they're also saying, of course they're 855 00:34:21.830 --> 00:34:23.390 also think you need about 100. 856 00:34:23.390 --> 00:34:25.310 Stuart Gary: Well you need big feet, several hundred 857 00:34:25.310 --> 00:34:28.310 Bigfoots. It's not big. In order to have 858 00:34:28.310 --> 00:34:29.670 a viable breeding population. 859 00:34:29.670 --> 00:34:31.890 Tim Mendham: Yeah, yeah, that's right. And that's a lot of 860 00:34:31.890 --> 00:34:32.720 uh, Bigfoot 861 00:34:32.720 --> 00:34:35.040 Stuart Gary: not to be recorded by people who have cameras 862 00:34:35.040 --> 00:34:35.840 on their cell phones. 863 00:34:35.840 --> 00:34:37.280 Tim Mendham: That's exactly right. Everyone carries a 864 00:34:37.280 --> 00:34:39.120 camera now. You don't need a 16 mil camera. 865 00:34:39.280 --> 00:34:40.960 Everyone's got a camera in their pocket and 866 00:34:40.960 --> 00:34:42.920 it's pretty good quality. But no one has 867 00:34:42.920 --> 00:34:44.400 really come up with definitive film. It's 868 00:34:44.400 --> 00:34:46.550 amazing how often people see Bigfoot and uh, 869 00:34:46.600 --> 00:34:48.520 some of them for a lengthy period of time but 870 00:34:48.520 --> 00:34:50.400 forget to film it. And there's no. Every 871 00:34:50.400 --> 00:34:52.920 Bigfoot that you most see these days is 872 00:34:52.920 --> 00:34:54.640 fuzzy. Perhaps Bigfoot fuzzy. 873 00:34:54.640 --> 00:34:56.510 Stuart Gary: Squatch blobs. They're called Squatch blobs. 874 00:34:57.860 --> 00:34:59.700 Tim Mendham: And um, I don't know, it's, it's a 875 00:34:59.860 --> 00:35:02.620 fascinating area for as much for its um, the 876 00:35:02.620 --> 00:35:04.860 psychology of belief as it is for any actual 877 00:35:04.860 --> 00:35:07.220 evidence of a humanoid. People want to 878 00:35:07.220 --> 00:35:10.140 believe. People do. And yeah, that's okay. 879 00:35:10.140 --> 00:35:11.740 People want to believe. That doesn't mean 880 00:35:11.740 --> 00:35:12.220 it's true. 881 00:35:12.220 --> 00:35:14.780 Stuart Gary: That's the sceptics. Timms Mendham. And this 882 00:35:14.780 --> 00:35:15.780 is Space Time. 883 00:35:31.310 --> 00:35:34.230 And that's the show for now. Space Time is 884 00:35:34.230 --> 00:35:36.430 available every Monday, Wednesday and Friday 885 00:35:36.430 --> 00:35:38.990 through bytes.com soundcloud, 886 00:35:38.990 --> 00:35:41.390 YouTube, your favourite podcast download 887 00:35:41.390 --> 00:35:42.590 provider, and from 888 00:35:42.590 --> 00:35:44.670 spacetimewithstuartgarry.com 889 00:35:45.310 --> 00:35:47.270 spacetime's also broadcast through the 890 00:35:47.270 --> 00:35:49.430 National Science foundation on Science Zone 891 00:35:49.430 --> 00:35:52.010 Radio and on both iHeartradio and 892 00:35:52.010 --> 00:35:54.930 TuneIn radio. And you can help to support our 893 00:35:54.930 --> 00:35:57.610 show by visiting the Space Store for a range 894 00:35:57.610 --> 00:36:00.370 of promotional merchandising goodies or by 895 00:36:00.370 --> 00:36:02.770 becoming a Space patron, which gives you 896 00:36:02.770 --> 00:36:04.770 access to triple episode commercial free 897 00:36:04.770 --> 00:36:07.290 versions of the show as well as lots of bonus 898 00:36:07.290 --> 00:36:09.690 audio content which doesn't go to air, access 899 00:36:09.690 --> 00:36:12.010 to our exclusive Facebook group and other 900 00:36:12.010 --> 00:36:13.890 rewards. Just go to 901 00:36:13.890 --> 00:36:16.330 spacetimewithstuartgarry.com for full 902 00:36:16.330 --> 00:36:19.290 details. You've been listening to Space Time 903 00:36:19.290 --> 00:36:21.770 with Stuart Gary. This has been another 904 00:36:21.770 --> 00:36:24.730 quality podcast production from bytes.com.