Bản chép lời đầy đủ của S26E80: Exploring Stellar Demise and Laser Communications: Space News Podcast

35 00:02:24,869 --> 00:02:29,089 Levin says this is exciting both for understanding how stars die 36 00:02:29,098 --> 00:02:31,399 and for answering other questions such as what 37 00:02:31,408 --> 00:02:34,869 unexpected sources could create gravitational waves that we 38 00:02:34,878 --> 00:02:36,229 detect here on Earth. 39 00:02:36,720 --> 00:02:40,949 Ancient Galaxies are long past their star forming prime and so 40 00:02:40,960 --> 00:02:44,589 would have few if any remaining giant stars, the principal 41 00:02:44,600 --> 00:02:49,029 source of long duration gamma ray bursts, their galactic cores 42 00:02:49,039 --> 00:02:52,309 however, are teeming with stars in a collection of ultra dense 43 00:02:52,320 --> 00:02:55,929 stellar remnants such as white dwarves, neutron stars and 44 00:02:55,940 --> 00:02:57,669 stellar mass black holes. 45 00:02:58,070 --> 00:03:01,809 Now, astronomers have long suspected that in this turbulent 46 00:03:01,820 --> 00:03:05,500 beehive of activity surrounding a supermassive black hole, it 47 00:03:05,509 --> 00:03:08,729 would only be a matter of time for two stellar objects to 48 00:03:08,740 --> 00:03:12,259 collide with each other producing a long duration gamma 49 00:03:12,270 --> 00:03:13,220 ray burst. 50 00:03:13,630 --> 00:03:17,860 The trouble is evidence of this type of merger has been elusive, 51 00:03:18,699 --> 00:03:22,880 but maybe all that's changed. Now, the first hint that such an 52 00:03:22,889 --> 00:03:26,979 event had occurred was seen on the 19th of October 2019 when 53 00:03:26,990 --> 00:03:30,580 NASA's Swift Space telescope detected a bright flash of gamma 54 00:03:30,589 --> 00:03:32,869 rays that lasted for more than a minute. 55 00:03:33,199 --> 00:03:35,779 Now, any gamma ray burst lasting for more than two seconds is 56 00:03:35,789 --> 00:03:39,009 considered long. And these bursts typically come from the 57 00:03:39,020 --> 00:03:42,410 supernova death of stars at least 10 times the mass of our 58 00:03:42,419 --> 00:03:46,850 sun. But not always. The authors then use the Gemini South 59 00:03:46,860 --> 00:03:50,350 telescope to undertake some long term observations of the gamma 60 00:03:50,360 --> 00:03:54,250 ray bursts fading afterglow to learn more about its origins. 61 00:03:54,539 --> 00:03:58,190 Now, these observations allow the team to pinpoint the exact 62 00:03:58,199 --> 00:04:01,770 location of the gamma ray burst to a region less than 100 light 63 00:04:01,779 --> 00:04:05,929 years from the nucleus of an ancient galaxy, placing it very 64 00:04:05,940 --> 00:04:08,889 near that galaxy's supermassive black hole. 65 00:04:09,210 --> 00:04:12,000 And when they studied the area in more detail, Leven and 66 00:04:12,009 --> 00:04:15,880 colleagues found no evidence of a corresponding supernova which 67 00:04:15,889 --> 00:04:19,059 would have left its imprint in the light studied by a Gemini 68 00:04:19,070 --> 00:04:23,220 South Levin says follow up observations suggested that 69 00:04:23,230 --> 00:04:26,720 rather than being a massive star collapsing, the burst was most 70 00:04:26,730 --> 00:04:30,160 likely caused by the merger of two compact objects. 71 00:04:30,450 --> 00:04:33,220 He says by pinpointing its location to the center of a 72 00:04:33,230 --> 00:04:36,339 previously identified ancient galaxy, they've had their first 73 00:04:36,350 --> 00:04:39,790 tantalizing evidence of a new pathway for stars to meet their 74 00:04:39,799 --> 00:04:40,820 demise. 75 00:04:41,179 --> 00:04:43,869 Now, in normal galactic environments, the production of 76 00:04:43,880 --> 00:04:47,040 long duration gamma ray bursts from colliding stellar remnants 77 00:04:47,049 --> 00:04:50,779 such as neutron stars or stellar mass black holes is thought to 78 00:04:50,790 --> 00:04:54,989 be vanishingly rare. The course of ancient Galaxies however, are 79 00:04:55,000 --> 00:04:58,720 anything but normal and there may be a million or more stars. 80 00:04:58,730 --> 00:05:00,260 All crammed into a region. 81 00:05:00,269 --> 00:05:05,640 Just a few layers across such extreme population densities may 82 00:05:05,649 --> 00:05:08,779 be great enough for the occasional stellar collisions to 83 00:05:08,790 --> 00:05:12,779 occur, especially under the titanic gravitational influence 84 00:05:12,790 --> 00:05:15,769 of a supermassive black hole which would perturb the motions 85 00:05:15,779 --> 00:05:19,299 of stars, setting them Carey in random directions. 86 00:05:19,700 --> 00:05:23,480 Eventually, these wayward stars would intersect and merge, 87 00:05:23,489 --> 00:05:27,119 triggering a titanic explosion which could be observed over 88 00:05:27,130 --> 00:05:31,269 vast cosmic distances. Now, it's likely that similar events are 89 00:05:31,279 --> 00:05:34,209 occurring all the time in crowded regions right across the 90 00:05:34,220 --> 00:05:36,989 universe, but they've gone unnoticed until now. 91 00:05:37,209 --> 00:05:40,510 Now, a possible reason for their obscurity could be that galactic 92 00:05:40,519 --> 00:05:43,959 centers are brimming with dust and gas and they could hide the 93 00:05:43,970 --> 00:05:46,570 initial flash of the gamma ray burst and the resulting 94 00:05:46,579 --> 00:05:51,170 afterglow. So this particular long duration gamma ray burst, 95 00:05:51,179 --> 00:05:55,230 which by the way has been cataloged as GRB 1910 19. 96 00:05:55,239 --> 00:05:59,230 A may be a rare exception allowing astronomers to detect 97 00:05:59,239 --> 00:06:03,869 the burst and study its after effects. This is space time 98 00:06:04,230 --> 00:06:07,559 still to come Australia, developing a new Deep Space 99 00:06:07,570 --> 00:06:12,250 Laser Communications Network and the unusual origins of the 100 00:06:12,260 --> 00:06:17,440 geminid meteor shower, all that and more still to come on space 101 00:06:17,450 --> 00:06:18,059 time. 102 00:06:32,750 --> 00:06:35,609 Last week, on space time, we

looked at the massive upgrade 103 00:06:35,619 --> 00:06:39,089 now under way at NASA's Deep Space Communications Network and 104 00:06:39,100 --> 00:06:43,029 its primary base stations at Goldstone, California Madrid 105 00:06:43,040 --> 00:06:46,869 Spain and at Tid Bin Villa on the outskirts of Canberra. 106 00:06:47,130 --> 00:06:50,649 Now, as we mentioned last week, part of that upgrade involves 107 00:06:50,660 --> 00:06:53,209 experimenting with new high speed laser optical 108 00:06:53,220 --> 00:06:57,130 communication systems, both between spacecraft and between 109 00:06:57,140 --> 00:07:00,730 space and the ground. An Australian project is now 110 00:07:00,739 --> 00:07:03,579 underway to develop an operational optical laser 111 00:07:03,589 --> 00:07:06,920 communications network specifically designed to talk to 112 00:07:06,929 --> 00:07:10,399 spacecraft both in orbit and also deep space. 113 00:07:10,720 --> 00:07:14,329 It's called terra net and it's at least 1000 times faster than 114 00:07:14,339 --> 00:07:17,679 the radio communications systems currently used to communicate in 115 00:07:17,690 --> 00:07:21,119 space. Associate Professor Sascha Schediwy from the 116 00:07:21,130 --> 00:07:22,910 University Of Western Australia. 117 00:07:22,920 --> 00:07:25,970 No, at the International Center For Radio Astronomy Research 118 00:07:25,980 --> 00:07:28,790 says the project will be one of the first commercial optical 119 00:07:28,799 --> 00:07:31,649 communications networks in Australia to be capable of 120 00:07:31,660 --> 00:07:35,549 providing day to day support for space missions. The network's 121 00:07:35,559 --> 00:07:39,230 main commercial application will be transferring data to and from 122 00:07:39,239 --> 00:07:40,950 satellites orbiting the planet. 123 00:07:41,350 --> 00:07:45,000 One of the strongest drivers for increased data rates is the rise 124 00:07:45,010 --> 00:07:48,510 of advanced Earth observation and imaging satellites carrying 125 00:07:48,519 --> 00:07:52,679 hyper spectral cameras. These satellites take high resolution 126 00:07:52,690 --> 00:07:55,859 images of the Earth's surface used for National Defense and 127 00:07:55,869 --> 00:07:59,420 disaster management in the process, generating huge amounts 128 00:07:59,429 --> 00:08:00,220 of data. 129 00:08:00,619 --> 00:08:03,299 In fact, currently, the data on some of these satellites needs 130 00:08:03,309 --> 00:08:06,750 to be compressed or thrown away because the capacity is simply 131 00:08:06,760 --> 00:08:11,089 not there to down link at all. Shed. Schediwy says by expanding 132 00:08:11,100 --> 00:08:14,609 to optical communications with a ground station network capable 133 00:08:14,619 --> 00:08:17,170 of supporting them terran net will be able to use them to 134 00:08:17,179 --> 00:08:18,459 their full capacity. 135 00:08:18,809 --> 00:08:21,489 The project which has been partly funded by the Australian 136 00:08:21,500 --> 00:08:24,760 Space Agency will also explore high speed communications in 137 00:08:24,769 --> 00:08:28,209 deep space including the moon and will be capable of providing 138 00:08:28,220 --> 00:08:31,910 the communications needed for NASA's atom lunar missions. 139 00:08:32,309 --> 00:08:36,219 The initial network will be made up of two fixed ground stations, 140 00:08:36,229 --> 00:08:39,690 one at the University Of Western Australia and the other at Mingo 141 00:08:40,630 --> 00:08:44,260 with a third mobile station initially deployed at New Norcia 142 00:08:44,270 --> 00:08:49,109 and it should be operational by 2026 shed. Schediwy says NASA 143 00:08:49,119 --> 00:08:52,820 and other space agencies need communication stations worldwide 144 00:08:52,830 --> 00:08:56,109 in order to maintain continuous contact with missions as the 145 00:08:56,119 --> 00:08:57,349 Earth rotates. 146 00:08:57,539 --> 00:08:59,469 Associate Professor Sascha Sch.: The terrine project is about 147 00:08:59,479 --> 00:09:03,169 taking some of the cutting edge technologies that were developed 148 00:09:03,179 --> 00:09:06,390 here at the International Center For Radio Astronomy Research 149 00:09:06,500 --> 00:09:09,059 located at the University Of Western Australia and 150 00:09:09,070 --> 00:09:14,669 translating those technologies into the world's first optical 151 00:09:14,679 --> 00:09:16,770 communications ground station network. 152 00:09:16,780 --> 00:09:21,090 This network will allow us to download critical data from 153 00:09:21,099 --> 00:09:24,770 satellites in space to Earth faster than has ever been done 154 00:09:24,780 --> 00:09:29,460 before. It allows us to also create commercialization 155 00:09:29,469 --> 00:09:33,070 opportunities for our industry partners. Goon Heli Australia, 156 00:09:33,080 --> 00:09:36,700 Tallis, Australia and our other partners around the world, 157 00:09:36,710 --> 00:09:40,890 including the German Space Agency, the French Space Agency 158 00:09:40,900 --> 00:09:42,669 and the European Space Agency. 159 00:09:42,859 --> 00:09:45,950 So with this project, we're going to be able to validate the 160 00:09:45,960 --> 00:09:48,682 commercial opportunities for this ground station and then 161 00:09:48,692 --> 00:09:53,732 have it be a revenue stream for income into the state going 162 00:09:53,742 --> 00:09:56,353 forward. One of the key challenges facing the world at 163 00:09:56,362 --> 00:10:00,043 the moment is with the explosion of satellites, er the number of 164 00:10:00,052 --> 00:10:04,083 satellites in orbit and the increasing capability, we don't 165 00:10:04,093 --> 00:10:07,533 have enough bandwidth to get all that information down on the 166 00:10:07,543 --> 00:10:08,103 ground. 167 00:10:08,432 --> 00:10:11,885 One of the things that Terrene will allow us to do is move on 168 00:10:11,895 --> 00:10:16,005 to a new technology, optical communications technologies and 169 00:10:16,015 --> 00:10:20,695 this will allow us to

download information from space thousands 170 00:10:20,705 --> 00:10:22,806 of times faster than it is currently possible. 171 00:10:22,815 --> 00:10:25,236 Stuart Gary: That's Associate Professor Sasa Shed we from the 172 00:10:25,245 --> 00:10:28,546 University Of Western Australia node of the International Center 173 00:10:28,556 --> 00:10:30,495 For Radio Astronomy Research. 174 00:10:30,825 --> 00:10:36,679 And this space time still to come the unusual origin of the 175 00:10:36,690 --> 00:10:40,260 geminid meteor shower and later in the science report, a new 176 00:10:40,270 --> 00:10:43,599 study shows that just like the modern day white pointer Karang 177 00:10:44,260 --> 00:10:49,340 Cacao, the ancient giant shark Megalodon was also warm blooded 178 00:10:49,700 --> 00:10:53,080 all that and more still to come on space time. 179 00:11:08,719 --> 00:11:12,479 Every December, the geminid meteor shower lights up the 180 00:11:12,489 --> 00:11:16,849 night skies of planet Earth. But mysteries surrounding the origin 181 00:11:16,859 --> 00:11:21,020 of this meteor stream have long fascinated scientists because 182 00:11:21,030 --> 00:11:24,219 while most meteor showers are created when a comet emits a 183 00:11:24,229 --> 00:11:28,359 tail of dust and ice, the geminid actually stem from an 184 00:11:28,369 --> 00:11:32,559 asteroid, a chunk of rock that normally doesn't produce a tail. 185 00:11:32,969 --> 00:11:36,020 Till recently, the geminid had only ever been studied from 186 00:11:36,030 --> 00:11:39,239 Earth. But now scientists have used observations from NASA's 187 00:11:39,250 --> 00:11:42,679 Parker Solar probe mission to study the sun to deduce that the 188 00:11:42,690 --> 00:11:46,669 geminid may have been created by a violent catastrophic event 189 00:11:46,679 --> 00:11:49,549 such as a high speed collision with another body or some 190 00:11:49,559 --> 00:11:51,030 gaseous explosion. 191 00:11:51,489 --> 00:11:54,500 The findings reported in the planetary science journal 192 00:11:54,510 --> 00:11:58,059 narrowed down hypotheses about the asteroid's composition in 193 00:11:58,070 --> 00:12:02,719 history which may explain its unconventional behavior. One of 194 00:12:02,729 --> 00:12:06,400 the study's authors, Jamie Sale from Princeton University says 195 00:12:06,409 --> 00:12:09,750 asteroids are sort of like little time capsules dating back 196 00:12:09,760 --> 00:12:11,780 to the formation of the solar system. 197 00:12:12,150 --> 00:12:15,309 They were formed when it was formed and understanding their 198 00:12:15,320 --> 00:12:18,599 composition gives scientists another feature of the puzzle of 199 00:12:18,609 --> 00:12:22,539 the solar system's history. Unlike most known meteor showers 200 00:12:22,549 --> 00:12:25,979 that come from comets which are made up of ice and dust, the 201 00:12:25,989 --> 00:12:29,200 geminid stream seems to originate from an asteroid. 202 00:12:29,210 --> 00:12:34,030 A huge chunk of rock and metal cataloged as 3200 ft on the 203 00:12:34,039 --> 00:12:37,440 study's co-author wolf cougar also from Princeton says most 204 00:12:37,450 --> 00:12:40,780 meteoroid storms are formed by way of cometary debris trails. 205 00:12:40,789 --> 00:12:43,840 So it's unusual that this one is formed from an asteroid. 206 00:12:44,289 --> 00:12:46,729 Additionally, the streams actually orbiting slightly 207 00:12:46,739 --> 00:12:50,179 outside its pa and body when it's closest to the sun. 208 00:12:50,599 --> 00:12:54,400 When a comet travels close to the sun, it gets hotter, that 209 00:12:54,409 --> 00:12:58,190 heat causes ice on the surface and inside the comet to release 210 00:12:58,200 --> 00:13:03,070 lots of gas. Some of which drags bits of dust and ice with it and 211 00:13:03,080 --> 00:13:06,900 that forms a halo around the comet nucleus and also creates 212 00:13:06,909 --> 00:13:10,869 spectacular cometary tails. This material continues to troll 213 00:13:10,880 --> 00:13:14,020 behind the comet as it stays within the sun's gravitational 214 00:13:14,030 --> 00:13:14,690 pole. 215 00:13:15,010 --> 00:13:18,229 And over time, this repeated process fills the orbit of the 216 00:13:18,239 --> 00:13:22,500 parent body with material to form a meteoroid stream. But 217 00:13:22,510 --> 00:13:26,190 because asteroids like 3200 Faton are made of rock and 218 00:13:26,200 --> 00:13:29,440 metal, they're not typically affected by the sun's heat. In 219 00:13:29,450 --> 00:13:32,880 the same way, comets are that leaves scientists wondering 220 00:13:32,890 --> 00:13:36,780 exactly what's causing the formation of 3200 photos meteor 221 00:13:36,789 --> 00:13:39,020 stream across the night sky. 222 00:13:39,950 --> 00:13:43,460 Now, in the past, astronomers have seen bits of 1200 ft on 223 00:13:43,469 --> 00:13:47,179 flake off the parent body under the blistering head of the sun 224 00:13:47,190 --> 00:13:51,940 around closest approach. It's also been suggested a 1200 ft on 225 00:13:51,950 --> 00:13:54,710 which appears to be on a cometary orbit. Not that of a 226 00:13:54,719 --> 00:13:58,700 typical asteroid may be a dead comet one that's lost all its 227 00:13:58,710 --> 00:14:02,270 ice leaving behind only a rocky core which resembles an 228 00:14:02,280 --> 00:14:03,039 asteroid. 229 00:14:03,429 --> 00:14:07,190 But this is where the New Parker Solar probe data comes in. It 230 00:14:07,200 --> 00:14:10,299 shows that while some of the 30 to photons activities are 231 00:14:10,309 --> 00:14:13,349 related to temperature, the creation of the geminid stream 232 00:14:13,359 --> 00:14:17,419 itself was likely caused by something catastrophic to learn 233 00:14:17,429 --> 00:14:17,820 more. 234 00:14:17,830 --> 00:14:21,260 The authors used the New Parker Solar probe data to model three 235 00:14:21,270 --> 00:14:25,250 possible formation scenarios. And they then compare these 236 00:14:25,260 --> 00:14:28,190 models to existing

models created from Earth based 237 00:14:28,200 --> 00:14:31,950 observatories. These different models reflect the chain of 238 00:14:31,960 --> 00:14:35,260 events which would transpire according to the laws of physics 239 00:14:35,270 --> 00:14:37,270 based on different scenarios. 240 00:14:37,710 --> 00:14:40,549 And the authors found that a violent collision with another 241 00:14:40,559 --> 00:14:44,140 object or alternatively a gaseous explosion rather than 242 00:14:44,150 --> 00:14:47,590 just being baked by the sun on a close approach was most 243 00:14:47,599 --> 00:14:51,590 consistent with the Parker Solar probe data and probably best 244 00:14:51,599 --> 00:15:13,710 explains the genes we see now this space time and time to take 245 00:15:13,719 --> 00:15:16,219 another brief look at some of the other stories making news in 246 00:15:16,229 --> 00:15:16,580 science. 247 00:15:16,590 --> 00:15:20,729 This week with the science report, archaeologists have 248 00:15:20,739 --> 00:15:23,809 discovered the oldest known caving gravings made by 249 00:15:23,820 --> 00:15:26,369 Neanderthals ever found in France. 250 00:15:26,729 --> 00:15:29,919 The findings reported in the journal plans are thought to be 251 00:15:29,929 --> 00:15:35,059 over 57,000 years old based on the shape spacing and 252 00:15:35,070 --> 00:15:37,599 arrangement of these engravings. Scientists think they're 253 00:15:37,609 --> 00:15:40,599 deliberate organized and intentional finger fluting 254 00:15:40,609 --> 00:15:44,659 created by human hands. Further dating of the cave found that it 255 00:15:44,669 --> 00:15:48,619 would have become closed off by infilling sediment around 57,000 256 00:15:48,630 --> 00:15:49,260 years ago. 257 00:15:49,270 --> 00:15:53,229 Long before Homo sapiens were established in the region. This 258 00:15:53,239 --> 00:15:56,090 combined with the stone tools found in the cave strongly 259 00:15:56,099 --> 00:15:59,960 suggest the engravings are work of Neanderthals and suggested 260 00:15:59,969 --> 00:16:03,440 their behavior and culture may have been similarly complex and 261 00:16:03,450 --> 00:16:06,169 diverse as those of Homo sapiens. 262 00:16:07,619 --> 00:16:11,309 A new study has found that as men age, some of their cells 263 00:16:11,320 --> 00:16:15,210 lose the very thing that makes them biological males, they're Y 264 00:16:15,219 --> 00:16:19,869 chromosomes and it turns out this loss hampers the body's 265 00:16:19,880 --> 00:16:21,729 ability to fight cancer. 266 00:16:22,119 --> 00:16:24,989 The study reported in the journal nature found the loss of 267 00:16:25,000 --> 00:16:28,530 the Y chromosome helps cancer cells evade the body's immune 268 00:16:28,539 --> 00:16:32,049 system. This apparently common impact in the aging process in 269 00:16:32,059 --> 00:16:35,570 men results in aggressive bladder cancer but somehow also 270 00:16:35,580 --> 00:16:38,669 renders the disease more vulnerable and responsive to a 271 00:16:38,679 --> 00:16:41,909 standard treatment called immune checkpoint inhibitors. 272 00:16:42,260 --> 00:16:45,450 Now, based on their research, scientists developing a test for 273 00:16:45,460 --> 00:16:49,210 the loss of the Y chromosome in tumors. With the goal of helping 274 00:16:49,219 --> 00:16:52,289 clinicians tailor immune checkpoint inhibitor treatments 275 00:16:52,299 --> 00:16:54,609 for male patients with bladder cancer. 276 00:16:56,059 --> 00:16:59,479 A new study shows that one of the largest carnivores ever to 277 00:16:59,489 --> 00:17:02,809 live on the face of the Earth, the gigantic shark, Megalodon 278 00:17:03,250 --> 00:17:06,989 was warm blooded. The findings reported in the journal, the 279 00:17:07,000 --> 00:17:09,729 proceedings of the National Academy Of Sciences confirms 280 00:17:09,739 --> 00:17:12,479 that Megalodon s body temperature was much higher than 281 00:17:12,489 --> 00:17:13,650 previously thought. 282 00:17:14,010 --> 00:17:17,489 Megalodon, which lived in the oceans between 23 million and 283 00:17:17,500 --> 00:17:21,920 3.6 million years ago, could reach lengths of over 20 m or 60 284 00:17:21,930 --> 00:17:25,920 ft and was the apex predator of the ocean during its reign. 285 00:17:26,209 --> 00:17:29,630 Previous studies had suggested that Megalodon was likely warm 286 00:17:29,640 --> 00:17:33,935 blooded or more precisely regionally endo thermic, just 287 00:17:33,944 --> 00:17:37,375 like some modern day sharks, including Karine Karri, the 288 00:17:37,385 --> 00:17:39,255 great white or white pointer. 289 00:17:39,415 --> 00:17:42,234 We've previously reported average body temperatures 290 00:17:42,244 --> 00:17:47,114 ranging from 22 to 26.6 degrees Celsius, which could be between 291 00:17:47,125 --> 00:17:51,635 10 and 21 degrees Celsius higher than ambient ocean temperatures. 292 00:17:52,015 --> 00:17:55,324 However, the new study instead suggests that Megalodon had an 293 00:17:55,334 --> 00:17:59,780 overall average body temperature of 27 degrees Celsius. And while 294 00:17:59,790 --> 00:18:03,000 previous studies were based on pure inference, the new research 295 00:18:03,010 --> 00:18:06,329 provides the first empirical evidence of warm bloodedness in 296 00:18:06,339 --> 00:18:09,560 the extinct shark. See, the research team used a novel 297 00:18:09,569 --> 00:18:10,859 geochemical technique. 298 00:18:10,869 --> 00:18:13,719 It involved both clumped isotope, thermometry and 299 00:18:13,729 --> 00:18:17,060 phosphate oxygen isotope thermometry in order to test the 300 00:18:17,069 --> 00:18:20,939 Megalodon endothermic hypothesis. The new study found 301 00:18:20,949 --> 00:18:23,800 that Megalodon had a body temperature significantly higher 302 00:18:23,810 --> 00:18:27,069 than sharks considered cold blooded or ecto. The mic 303 00:18:27,079 --> 00:18:30,349 consistent with the fossil shark having a degree of internal heat 304 00:18:30,359 --> 00:18:33,000 production as

modern warm blooded animals. 305 00:18:33,010 --> 00:18:38,430 Do hackers find a new way to get around voice authentication 306 00:18:38,439 --> 00:18:42,239 security systems and using artificial intelligence to 307 00:18:42,250 --> 00:18:46,449 determine which songs are likely to be hits and which are misses 308 00:18:46,869 --> 00:18:49,939 with the details. We're joined by technology editor Alex 309 00:18:49,949 --> 00:18:52,430 Zaharov-Reutt from Tech Visar live. 310 00:18:52,439 --> 00:18:53,989 Alex Zaharov-Reutt: Well, computer scientists at Canada's 311 00:18:54,000 --> 00:18:57,390 University Of Waterloo have discovered a method of attack 312 00:18:57,400 --> 00:19:01,020 and can successfully bypass voice authentication security 313 00:19:01,030 --> 00:19:04,099 systems and they're claiming up to a 99 per cent success rate 314 00:19:04,109 --> 00:19:05,390 after only six tries. 315 00:19:05,400 --> 00:19:07,959 Now, obviously, this is bad news for the voice authentication 316 00:19:07,969 --> 00:19:10,300 systems used by banks and government departments call 317 00:19:10,310 --> 00:19:13,729 centers, etc, where they let you log into services by voice and 318 00:19:13,739 --> 00:19:16,175 normally you enroll your voice print by repeating a certain 319 00:19:16,185 --> 00:19:17,474 phrase in your own voice. 320 00:19:17,484 --> 00:19:20,704 The system then extracts your unique vocal signature or voice 321 00:19:20,714 --> 00:19:23,104 print and you can log in and when you repeat a different 322 00:19:23,114 --> 00:19:26,114 phrases in the future, they will compare those two. But obviously 323 00:19:26,125 --> 00:19:28,704 hackers figured out they could use deep fakes to generate 324 00:19:28,714 --> 00:19:30,665 convincing copies of your voice. 325 00:19:30,675 --> 00:19:33,285 And so that obviously led to people making voice 326 00:19:33,295 --> 00:19:36,505 authentication systems to come up with defenses, spoofing 327 00:19:36,515 --> 00:19:38,935 counter measures. But the University Of Waterloo 328 00:19:38,944 --> 00:19:43,250 researchers have identified markers in deep fake audio that 329 00:19:43,260 --> 00:19:45,689 betray that it is being computer generated. 330 00:19:45,699 --> 00:19:48,150 And they wrote a program that removes these markers, making it 331 00:19:48,160 --> 00:19:52,329 indistinguishable from authentic audio. So they tested it against 332 00:19:52,339 --> 00:19:55,319 Amazon connects voice authentication system. Now, 333 00:19:55,329 --> 00:19:58,729 that's a bit more advanced. They only had a 10% success rate in 334 00:19:58,739 --> 00:20:02,520 14 2nd attack. This rate rose to over 40% in less than 30 335 00:20:02,530 --> 00:20:02,930 seconds. 336 00:20:02,939 --> 00:20:05,400 But with some of the less sophisticated voice 337 00:20:05,410 --> 00:20:08,530 authentication systems, they targeted, they achieved a 99% 338 00:20:08,540 --> 00:20:11,785 success rate after six attempts. And they're saying that the only 339 00:20:11,795 --> 00:20:14,604 way to create a secure system is to think like an attacker. If 340 00:20:14,614 --> 00:20:16,285 you don't, you're just wanting to be attacked. 341 00:20:16,295 --> 00:20:18,614 And they say that by demonstrating the insecurity of 342 00:20:18,625 --> 00:20:21,375 voice authentication, we hope that companies relying on voice 343 00:20:21,385 --> 00:20:23,854 authentication as their only authentication factor will 344 00:20:23,864 --> 00:20:26,895 consider deploying additional or stronger authentication 345 00:20:26,905 --> 00:20:27,224 measures. 346 00:20:27,234 --> 00:20:29,505 And this is what's very important to use the Google or 347 00:20:29,515 --> 00:20:32,944 Microsoft or some sort of other authentication app and not rely 348 00:20:32,954 --> 00:20:36,185 upon the SMS messages that come through. Because if somebody 349 00:20:36,194 --> 00:20:39,170 steals a thing out of your phone or convinces a phone company to 350 00:20:39,180 --> 00:20:42,380 transfer your SIM over to an E SIM in one of their phones. 351 00:20:42,390 --> 00:20:44,969 And you have all of your banking and other systems set up to 352 00:20:44,979 --> 00:20:47,900 receive an SMS message. They'll get those messages you won't. 353 00:20:47,910 --> 00:20:49,729 And a lot of people have been caught in that way. So 354 00:20:49,739 --> 00:20:52,790 definitely use as many factors of authentication as you can and 355 00:20:52,800 --> 00:20:55,239 voice is sadly not invulnerable. 356 00:20:55,250 --> 00:20:57,920 Stuart Gary: And the other big story this week has been AI has 357 00:20:57,930 --> 00:21:00,910 now moved into the music industry in a different way to 358 00:21:00,920 --> 00:21:04,435 what one might expect by looking at your heartbeat and being to 359 00:21:04,444 --> 00:21:05,964 work out what you're into. 360 00:21:05,994 --> 00:21:07,645 Alex Zaharov-Reutt: Yeah, look, this was because the US 361 00:21:07,655 --> 00:21:11,155 Entertainment magazine variety revealed last year that there 362 00:21:11,165 --> 00:21:15,074 are over 100,000 songs released every single day to all the 363 00:21:15,084 --> 00:21:17,944 major streaming services like Spotify, Apple Music and others. 364 00:21:17,954 --> 00:21:21,185 And the problem is that whether it's using human intuition, 365 00:21:21,194 --> 00:21:24,964 aided by existing algorithms to analyze the song's lyrics and 366 00:21:24,974 --> 00:21:27,864 other metadata to predict hits, they're only getting about a 50 367 00:21:27,875 --> 00:21:29,935 per cent success rate, which is sort of one in two. 368 00:21:29,944 --> 00:21:34,520 So Paul Jz, a professor at Claremont Graduate University 369 00:21:34,530 --> 00:21:38,060 and the senior author of this study was telling Z magazine 370 00:21:38,069 --> 00:21:41,410 that they use neurological data and AI techniques to see how our 371 00:21:41,420 --> 00:21:44,849 brains respond to music. And Zach stated that my lab 372 00:21:44,859 -->

00:21:47,209 previously identified what appears to be the brain's 373 00:21:47,219 --> 00:21:51,140 valuation system for social and emotional experiences, which is 374 00:21:51,150 --> 00:21:52,630 called immersion. 375 00:21:52,640 --> 00:21:54,829 And in talks to the streaming service, he says they told me 376 00:21:54,839 --> 00:21:57,469 that they struggled to suggest new music for subscribers due to 377 00:21:57,479 --> 00:22:00,915 the high volume of new music, 1000 songs every day is a lot. I 378 00:22:00,925 --> 00:22:05,064 mean, sadly most of it's crap, all the hits from the last 379 00:22:05,074 --> 00:22:05,775 century. 380 00:22:05,785 --> 00:22:08,645 But you know, so he says that he thought that measuring this 381 00:22:08,655 --> 00:22:12,564 neurologic immersion could help solve the problems. And so he 382 00:22:12,574 --> 00:22:15,314 had 33 participants from the university campus and from the 383 00:22:15,484 --> 00:22:18,915 community and they fitted them with non invasive neurop 384 00:22:18,954 --> 00:22:22,574 physiological recording devices using commercially available off 385 00:22:22,584 --> 00:22:25,635 the shelf devices such as cardiac sensors on smart 386 00:22:25,645 --> 00:22:26,135 watches. 387 00:22:26,145 --> 00:22:29,280 And then they fed this data into their immersion Neuroscience 388 00:22:29,459 --> 00:22:32,319 platform, which uses this data including a person's heart rate 389 00:22:32,329 --> 00:22:37,219 to infer neural states from the activity of cranial nerves. 390 00:22:37,229 --> 00:22:41,040 And so basically, by using these brain signals, they looked at 24 391 00:22:41,050 --> 00:22:43,170 recently released songs from a streaming service and they 392 00:22:43,180 --> 00:22:45,790 looked at three months of data to see whether the song was a 393 00:22:45,800 --> 00:22:49,150 hit or not based on the number of plays. And this set of songs 394 00:22:49,160 --> 00:22:50,760 included both hits and flops. 395 00:22:50,770 --> 00:22:55,324 And at least 700,000 listens on a particular service could tell 396 00:22:55,334 --> 00:22:57,724 that from their results. When people were listening, they 397 00:22:57,734 --> 00:23:00,145 could tell 97 per cent of the time whether the song was a hit 398 00:23:00,155 --> 00:23:02,925 or a flop and the strength of the system lies in the fact, 399 00:23:02,935 --> 00:23:05,035 these signals can be measured with something as simple as a 400 00:23:05,045 --> 00:23:06,655 smart watch or fitness armband. 401 00:23:06,665 --> 00:23:09,415 Whereas brain activity is typically recorded using 402 00:23:09,425 --> 00:23:12,194 cumbersome lab equipment. So whether this means we're going 403 00:23:12,204 --> 00:23:16,895 to hear a sea of sort of same, same songs that AI says is a hit 404 00:23:16,905 --> 00:23:18,354 or not. I don't know that's. 405 00:23:18,364 --> 00:23:21,604 Stuart Gary: Alex Sahara Roy from Tech Advice dot life. 406 00:23:37,250 --> 00:23:40,959 And that's the show for now. SpaceTime is available every 407 00:23:40,969 --> 00:23:44,660 Monday, Wednesday and Friday through Apple podcasts, itunes, 408 00:23:44,670 --> 00:23:49,869 Stitcher, Google podcast, pocket casts. Spotify, a cast Amazon 409 00:23:49,880 --> 00:23:54,489 music bites dot com. 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