1 00:00:03,000 --> 00:00:06,040 The universe holds a giant cosmic secret. 2 00:00:09,400 --> 00:00:12,760 Nobody's ever seen what a black hole really looks like. 3 00:00:15,880 --> 00:00:18,160 Now a team of international astronomers 4 00:00:18,160 --> 00:00:19,880 are on a mission to find out. 5 00:00:22,680 --> 00:00:24,760 Here we go. We're on! 6 00:00:24,760 --> 00:00:27,560 The team's director has dedicated his life 7 00:00:27,560 --> 00:00:31,200 to take the first ever picture of a black hole. 8 00:00:31,200 --> 00:00:34,000 If you ask why this hasn't been done before, 9 00:00:34,000 --> 00:00:36,600 it's because it's really, really hard. 10 00:00:36,600 --> 00:00:39,520 For two years, our cameras have followed these scientists 11 00:00:39,520 --> 00:00:42,600 to the most hostile environments in the world... 12 00:00:42,600 --> 00:00:44,520 It's pretty cold. 13 00:00:44,520 --> 00:00:47,200 The wind chill right now is around minus 70. 14 00:00:47,200 --> 00:00:51,640 ..as they build a revolutionary telescope the size of planet Earth. 15 00:00:54,320 --> 00:00:56,800 If they succeed, a picture of a black hole 16 00:00:56,800 --> 00:01:00,040 will challenge the theories of Albert Einstein 17 00:01:00,040 --> 00:01:04,400 and could pave the way to a new era of physics. 18 00:01:04,400 --> 00:01:08,400 It will be one of the most thrilling discoveries of our age. 19 00:01:11,920 --> 00:01:14,640 This is the inside story of the mission to capture 20 00:01:14,640 --> 00:01:17,080 the first real picture... 21 00:01:17,080 --> 00:01:19,200 ..of a black hole. 22 00:01:28,160 --> 00:01:30,920 Of all the wonders in our cosmos, 23 00:01:30,920 --> 00:01:35,400 one object has remained hidden to the greatest scientific minds. 24 00:01:38,240 --> 00:01:39,640 The black hole. 25 00:01:44,040 --> 00:01:47,600 A black hole is a region of space where the pull of gravity 26 00:01:47,600 --> 00:01:52,600 is so powerful that nothing at all can escape if it gets too close 27 00:01:52,600 --> 00:01:57,040 and, by nothing, I mean nothing, including even light itself. 28 00:01:58,720 --> 00:02:01,920 What we really mean by that is this area called the event horizon. 29 00:02:03,080 --> 00:02:06,560 It's a specific limit around the black hole that marks 30 00:02:06,560 --> 00:02:09,080 what's inside and what's outside. 31 00:02:09,080 --> 00:02:14,240 Once anything crosses that boundary, adios. It is out of contact 32 00:02:14,240 --> 00:02:15,840 with the rest of the universe. 33 00:02:15,840 --> 00:02:18,000 We don't know what its ultimate fate is, 34 00:02:18,000 --> 00:02:20,120 but probably it ain't very good. 35 00:02:23,680 --> 00:02:27,320 Most scientists today believe that black holes really exist... 36 00:02:29,000 --> 00:02:31,640 ..but nobody has ever actually seen one. 37 00:02:34,840 --> 00:02:40,560 We have identified lots of objects that look like black holes, 38 00:02:40,560 --> 00:02:43,200 but you can't prove that they're black holes. 39 00:02:43,200 --> 00:02:45,200 This is where the problem comes, right? 40 00:02:45,200 --> 00:02:48,480 If nobody has ever seen a black hole, 41 00:02:48,480 --> 00:02:51,840 can we be sure that they really exist? 42 00:02:51,840 --> 00:02:55,360 Could this fundamental notion about our universe 43 00:02:55,360 --> 00:02:58,120 and how it works be wrong? 44 00:03:03,600 --> 00:03:06,280 Astronomer Shep Doeleman is on a mission 45 00:03:06,280 --> 00:03:07,760 to solve this mystery. 46 00:03:11,360 --> 00:03:14,240 He's spearheading an extraordinary experiment. 47 00:03:15,560 --> 00:03:20,560 He wants to take the first ever picture of a black hole. 48 00:03:21,600 --> 00:03:25,440 The goal of the entire project is to see what a black hole 49 00:03:25,440 --> 00:03:28,200 really looks like, detect its shape, 50 00:03:28,200 --> 00:03:31,960 and see what's happening immediately surrounding it. 51 00:03:31,960 --> 00:03:34,400 I mean, just saying that gives me chills. 52 00:03:34,400 --> 00:03:38,480 I've been interested in black holes since I began doing astronomy. 53 00:03:38,480 --> 00:03:41,720 It's really kind of what got me into it in the first place. 54 00:03:41,720 --> 00:03:46,360 I kind of fell in with this crowd doing radio astronomy 55 00:03:46,360 --> 00:03:48,360 in a very special way. 56 00:03:54,280 --> 00:03:56,440 Here at the Haystack Observatory, 57 00:03:56,440 --> 00:03:58,160 and across the world, 58 00:03:58,160 --> 00:04:01,760 Shep has been developing a technique to try and see the unseen. 59 00:04:06,680 --> 00:04:09,560 Shep is targeting the very centre of the galaxy, 60 00:04:09,560 --> 00:04:13,360 where astronomers have detected a cluster of stars... 61 00:04:14,720 --> 00:04:17,000 ..orbiting something strange. 62 00:04:18,680 --> 00:04:21,080 The stars are orbiting so fast... 63 00:04:22,520 --> 00:04:26,080 ..scientists have calculated the object must have the mass 64 00:04:26,080 --> 00:04:29,080 of more than four million suns. 65 00:04:31,160 --> 00:04:32,960 The best explanation, 66 00:04:32,960 --> 00:04:36,880 a black hole called Sagittarius A-star. 67 00:04:38,120 --> 00:04:42,440 Shep wants to use radio telescopes to try and see this black hole, 68 00:04:42,440 --> 00:04:44,160 but there's a problem. 69 00:04:44,160 --> 00:04:47,240 Although it's predicted to be larger than the Sun, 70 00:04:47,240 --> 00:04:50,920 from Earth, it's 26,000 light years away. 71 00:04:52,360 --> 00:04:54,440 This is such a small target, 72 00:04:54,440 --> 00:04:58,000 there's no telescope in existence that has the power to see it. 73 00:04:59,520 --> 00:05:02,120 The entire reason this hasn't been done up till now 74 00:05:02,120 --> 00:05:04,800 is that black holes are extremely small. 75 00:05:04,800 --> 00:05:07,240 It would be the equivalent of trying to see an orange 76 00:05:07,240 --> 00:05:08,960 at the distance of the moon. 77 00:05:08,960 --> 00:05:11,120 So we have to build the telescope. 78 00:05:11,120 --> 00:05:13,560 We have to build a fundamentally new instrument 79 00:05:13,560 --> 00:05:15,720 that can see things that are that small. 80 00:05:17,960 --> 00:05:20,440 To achieve this unprecedented power, 81 00:05:20,440 --> 00:05:24,680 for the last decade, Shep has been working towards a master plan. 82 00:05:26,680 --> 00:05:31,000 He wants to combine eight separate telescopes in Spain, 83 00:05:31,000 --> 00:05:33,120 Mexico, 84 00:05:33,120 --> 00:05:35,040 Arizona... 85 00:05:37,360 --> 00:05:39,160 ..Hawaii, 86 00:05:39,160 --> 00:05:40,880 Chile, 87 00:05:40,880 --> 00:05:42,720 and the South Pole. 88 00:05:43,960 --> 00:05:46,720 This network is called the Event Horizon Telescope 89 00:05:46,720 --> 00:05:49,080 and spans the face of planet Earth. 90 00:05:50,360 --> 00:05:53,840 To capture the crucial image, all eight dishes must point towards 91 00:05:53,840 --> 00:05:56,960 the black hole at exactly the same time. 92 00:05:58,160 --> 00:06:02,360 We're linking telescopes 10,000km apart, 93 00:06:02,360 --> 00:06:05,320 even more than that. By spanning the globe, 94 00:06:05,320 --> 00:06:09,600 you create a new kind of instrument that can see a black hole. 95 00:06:09,600 --> 00:06:12,480 That's the secret sauce, 96 00:06:12,480 --> 00:06:15,560 that's the secret of the Event Horizon Telescope. 97 00:06:20,320 --> 00:06:23,880 Each of the eight telescopes in the network 98 00:06:23,880 --> 00:06:26,800 are unique and powerful observatories. 99 00:06:30,280 --> 00:06:32,840 They can detect emissions from around the black hole, 100 00:06:32,840 --> 00:06:36,920 but the team will need to combine these signals to make an image. 101 00:06:38,000 --> 00:06:39,480 Across the world, 102 00:06:39,480 --> 00:06:42,400 the team will observe the black holes simultaneously 103 00:06:42,400 --> 00:06:45,280 and record the data onto hard drives. 104 00:06:46,600 --> 00:06:50,360 Then they must physically transport the drives back 105 00:06:50,360 --> 00:06:53,440 and combine the data inside a giant supercomputer 106 00:06:53,440 --> 00:06:55,240 called a correlator. 107 00:06:57,120 --> 00:07:00,080 This correlator is the final piece of the puzzle. 108 00:07:00,080 --> 00:07:04,720 The first part is collecting data at different spots around the globe. 109 00:07:04,720 --> 00:07:07,120 The second piece, though, is combining that data 110 00:07:07,120 --> 00:07:08,920 and that's what the correlator does. 111 00:07:11,440 --> 00:07:15,880 Only then will this new Earth-sized telescope have a chance 112 00:07:15,880 --> 00:07:18,320 to make an image of a black hole. 113 00:07:19,840 --> 00:07:23,520 If the Event Horizon Telescope manages to actually 114 00:07:23,520 --> 00:07:26,560 take a high quality photo of a black hole, 115 00:07:26,560 --> 00:07:28,320 that's not an impressive feat, 116 00:07:28,320 --> 00:07:30,360 it's a mind-blowing feet. 117 00:07:30,360 --> 00:07:34,680 It's a technical tour de force like we've never seen before. 118 00:07:34,680 --> 00:07:39,960 But what does Shep's team hope to see if a black hole allows nothing, 119 00:07:39,960 --> 00:07:42,280 not even light, to escape? 120 00:07:47,480 --> 00:07:49,840 A black hole itself is invisible... 121 00:07:52,720 --> 00:07:56,200 ..but matter falling into it should give it away. 122 00:07:58,400 --> 00:08:02,000 It's intense gravity attracts interstellar gas, 123 00:08:02,000 --> 00:08:05,320 and pulls it into a faster and faster orbit. 124 00:08:08,240 --> 00:08:12,120 This heats the gas to billions of degrees 125 00:08:12,120 --> 00:08:15,720 and emits a light that the telescopes should be able to detect. 126 00:08:18,040 --> 00:08:21,520 The mathematics suggests gravity will warp these emissions 127 00:08:21,520 --> 00:08:23,680 into a circular ring, 128 00:08:23,680 --> 00:08:28,040 leaving in the centre the shadow of the black hole. 129 00:08:31,960 --> 00:08:34,840 It's an important scientific prediction. 130 00:08:34,840 --> 00:08:38,280 If the team sees something that isn't circular, 131 00:08:38,280 --> 00:08:43,320 it could turn the most treasured theory in physics on its head. 132 00:08:45,240 --> 00:08:48,640 Einstein's theory of general relativity. 133 00:08:50,120 --> 00:08:54,120 His theory says mass curves the fabric of space and time, 134 00:08:54,120 --> 00:08:57,520 creating an effect that we call gravity. 135 00:08:59,000 --> 00:09:03,280 Einstein's theory of relativistic gravity is what lays the foundations 136 00:09:03,280 --> 00:09:05,280 that sets all of our understanding. 137 00:09:06,680 --> 00:09:09,680 Step one is just, did Einstein get it right? 138 00:09:09,680 --> 00:09:12,080 Is there some detail that's been overlooked? 139 00:09:12,080 --> 00:09:16,240 For 100 years, Einstein's theory has passed every test. 140 00:09:17,480 --> 00:09:20,560 But nobody has ever seen its most extreme prediction. 141 00:09:22,120 --> 00:09:25,200 If enough mass could be crushed into a single point, 142 00:09:25,200 --> 00:09:29,840 its gravity would be so strong it would form a black hole. 143 00:09:31,960 --> 00:09:36,960 How wonderful would it be if the Event Horizon Telescope shows us 144 00:09:36,960 --> 00:09:41,640 that, in extreme realms, Einstein is not completely right? 145 00:09:41,640 --> 00:09:45,520 It will be one of the most thrilling discoveries of our age, 146 00:09:45,520 --> 00:09:48,760 as we will then leapfrog forward in our grasp 147 00:09:48,760 --> 00:09:50,600 of how the universe works. 148 00:09:50,600 --> 00:09:55,960 A challenge to Einstein's theory and a new era of astronomy 149 00:09:55,960 --> 00:10:00,120 rests on the success of the Event Horizon Telescope team. 150 00:10:09,200 --> 00:10:12,080 There are now just three months until the team will attempt 151 00:10:12,080 --> 00:10:16,360 to observe a black hole using a network of eight telescopes, 152 00:10:16,360 --> 00:10:18,280 but there's a lot to do. 153 00:10:20,640 --> 00:10:24,720 Shep has come to Mexico to oversee a crucial test run 154 00:10:24,720 --> 00:10:28,520 using four of the eight telescopes in the network. 155 00:10:29,920 --> 00:10:31,840 What really gets us out of bed, 156 00:10:31,840 --> 00:10:34,040 what really gets us motivated for this, 157 00:10:34,040 --> 00:10:37,520 is building a new kind of instrument. 158 00:10:37,520 --> 00:10:40,680 When you think of building a telescope as large as the Earth, 159 00:10:40,680 --> 00:10:44,400 that in and of itself is such a crazy idea. 160 00:10:45,520 --> 00:10:49,040 To link the telescopes, the team will use a technique 161 00:10:49,040 --> 00:10:53,760 called "very long baseline interferometry" or VLBI, 162 00:10:53,760 --> 00:10:55,760 but it poses a major challenge. 163 00:10:55,760 --> 00:10:57,400 During the observations, 164 00:10:57,400 --> 00:11:00,320 they won't see any results in real time. 165 00:11:00,320 --> 00:11:05,040 The very nature of the technique we're using is that we're not 166 00:11:05,040 --> 00:11:09,120 going to know if these observations work until we get all the data back 167 00:11:09,120 --> 00:11:11,320 to a central processing facility, 168 00:11:11,320 --> 00:11:14,360 so we're here to do what's called a dry run... 169 00:11:15,600 --> 00:11:19,160 ..to make sure that everything runs like clockwork. 170 00:11:19,160 --> 00:11:20,560 Scan two... 171 00:11:20,560 --> 00:11:23,840 Not 0.78, it's 0.078. 172 00:11:23,840 --> 00:11:27,640 We have crack ninja teams up here in Mexico, Chile, 173 00:11:27,640 --> 00:11:30,120 the South Pole, and Spain, 174 00:11:30,120 --> 00:11:32,480 and they all know their business, frankly. 175 00:11:32,480 --> 00:11:34,360 They know what to do. 176 00:11:34,360 --> 00:11:36,880 You check everything, and you check it again, 177 00:11:36,880 --> 00:11:39,080 and you check it three times. 178 00:11:39,080 --> 00:11:43,400 During the critical observation run, there's a lot that can go wrong. 179 00:11:50,640 --> 00:11:53,360 The radio emission from the black hole must be recorded 180 00:11:53,360 --> 00:11:54,960 at each telescope 181 00:11:54,960 --> 00:11:59,000 and the data stored onto specialised hard drives. 182 00:12:00,200 --> 00:12:04,400 Clouds can obscure the signal and equipment could fail... 183 00:12:05,560 --> 00:12:09,080 ..knocking one or more of the telescopes out of the network. 184 00:12:10,320 --> 00:12:14,200 So the team need clear weather and perfectly working telescopes 185 00:12:14,200 --> 00:12:18,320 at every location across the globe simultaneously. 186 00:12:20,200 --> 00:12:24,160 If just one telescope fails, they might not get an image. 187 00:12:25,240 --> 00:12:26,840 After the data have been recorded, 188 00:12:26,840 --> 00:12:29,200 the filled hard drives will be shipped 189 00:12:29,200 --> 00:12:31,800 to Massachusetts and Germany, 190 00:12:31,800 --> 00:12:34,000 where the data must be combined, 191 00:12:34,000 --> 00:12:37,560 and they will know if their ambitious plan has worked. 192 00:12:38,960 --> 00:12:41,000 Are things all set? I hope so. 193 00:12:41,000 --> 00:12:46,240 In Mexico, astronomer Gopal Narayanan is in charge. 194 00:12:46,240 --> 00:12:49,680 The whole purpose of the test observations we're doing 195 00:12:49,680 --> 00:12:52,720 is to bring in a couple of new facilities. 196 00:12:52,720 --> 00:12:56,480 We're going to bring in Apex, which is in Chile, 197 00:12:56,480 --> 00:13:00,520 Pico Veleta in Europe, and the South Pole Telescope. 198 00:13:04,680 --> 00:13:08,040 The South Pole is a critical location for the team. 199 00:13:08,040 --> 00:13:12,560 Its clear, frozen skies are perfect for observation. 200 00:13:15,040 --> 00:13:17,640 But flights here will soon stop for the winter, 201 00:13:17,640 --> 00:13:22,200 which means the data from the South Pole will be the last to return. 202 00:13:25,280 --> 00:13:28,760 Instrument expert Dan Marrone and his team have travelled 203 00:13:28,760 --> 00:13:31,720 here to the ends of the Earth to get the telescope ready. 204 00:13:31,720 --> 00:13:33,680 By including the South Pole Telescope, 205 00:13:33,680 --> 00:13:36,600 we really, truly make a telescope the size of the Earth. 206 00:13:36,600 --> 00:13:39,560 It more than doubles the resolution of the array 207 00:13:39,560 --> 00:13:42,560 and gives us that last bit of detail that we need 208 00:13:42,560 --> 00:13:44,560 to make a picture of a black hole. 209 00:13:46,400 --> 00:13:48,400 It's January. 210 00:13:48,400 --> 00:13:51,280 The weather is a biting 36 degrees below zero. 211 00:13:51,280 --> 00:13:52,720 So, it's pretty cold. 212 00:13:52,720 --> 00:13:55,440 The wind chill right now is around minus 70. 213 00:13:57,440 --> 00:14:00,840 Despite the cold, the teams still need to prepare 214 00:14:00,840 --> 00:14:02,480 for the test observations. 215 00:14:05,240 --> 00:14:08,240 They must install this custom built mirror to the telescope 216 00:14:08,240 --> 00:14:10,160 with submillimetre accuracy. 217 00:14:13,360 --> 00:14:15,840 OK, I do believe the tertiary is installed. 218 00:14:15,840 --> 00:14:18,200 We have to have this here, 219 00:14:18,200 --> 00:14:21,400 positioned so that the light from the giant ten-metre telescope 220 00:14:21,400 --> 00:14:24,080 is focused precisely on our receiver. 221 00:14:24,080 --> 00:14:26,040 So that took a little bit of doing, 222 00:14:26,040 --> 00:14:28,240 but we think we have it right about now. 223 00:14:28,240 --> 00:14:32,640 The mirror is in, but, until the observations are complete, 224 00:14:32,640 --> 00:14:34,960 they won't know if it's worked. 225 00:14:40,200 --> 00:14:44,320 Back in Mexico, Gopal and the team get ready to start the trial 226 00:14:44,320 --> 00:14:47,760 observation run with the four telescopes. 227 00:14:47,760 --> 00:14:51,160 They will observe bright sources called quasars 228 00:14:51,160 --> 00:14:52,960 to help test the new network. 229 00:14:55,720 --> 00:15:00,120 Data specialist Lindy Blackburn is in charge of recording the data. 230 00:15:00,120 --> 00:15:01,520 One minute to go. 231 00:15:01,520 --> 00:15:03,960 I'm ready to go. Is Lindy happy with this? 232 00:15:06,040 --> 00:15:07,400 Here we go! 233 00:15:07,400 --> 00:15:08,680 We're on. 234 00:15:09,800 --> 00:15:12,080 But, as the test observations begin... 235 00:15:14,840 --> 00:15:16,400 OK, recording. 236 00:15:16,400 --> 00:15:18,280 ..there's an unexpected problem. 237 00:15:20,640 --> 00:15:21,960 What? 238 00:15:21,960 --> 00:15:25,600 A bug in the code means the recording lights are not coming on. 239 00:15:25,600 --> 00:15:29,920 No, it's trying to record... Oh, it's trying to record. OK. 240 00:15:29,920 --> 00:15:33,360 Setting data to record, only the very last step 241 00:15:33,360 --> 00:15:35,280 in this whole fine process, 242 00:15:35,280 --> 00:15:37,680 which is albeit a very important step, 243 00:15:37,680 --> 00:15:40,800 which is to record that data we've collected all through the chain, 244 00:15:40,800 --> 00:15:42,880 that is not happening right now. 245 00:15:42,880 --> 00:15:44,720 Without data, 246 00:15:44,720 --> 00:15:47,440 the telescope is knocked out of the network. 247 00:15:48,800 --> 00:15:52,720 Lindy is working furiously to find a fix 248 00:15:52,720 --> 00:15:55,000 and I think we're hopeful. 249 00:15:55,000 --> 00:15:57,080 So the IF levels look fine? 250 00:15:57,080 --> 00:15:59,520 Yeah. Tell me it's workin, Lindy. 251 00:16:00,920 --> 00:16:02,600 No. No! 252 00:16:02,600 --> 00:16:04,040 BLEEP 253 00:16:05,920 --> 00:16:07,400 The same problem. 254 00:16:07,400 --> 00:16:10,200 I changed the order when I thought it was the initial problem... 255 00:16:10,200 --> 00:16:13,440 You're hoping that we'll get this recording this time, Lindy? 256 00:16:14,600 --> 00:16:16,200 I really don't know. 257 00:16:16,200 --> 00:16:18,080 One minute... Are we ready? 258 00:16:18,080 --> 00:16:20,200 Ten seconds to go. 259 00:16:24,720 --> 00:16:26,600 Lights! Yes! 260 00:16:28,920 --> 00:16:30,520 Good job, Lindy! 261 00:16:30,520 --> 00:16:32,240 It's 2:46am. 262 00:16:33,600 --> 00:16:37,040 The team have succeeded in recording the test data. 263 00:16:40,240 --> 00:16:42,440 But they won't find out if it's worked 264 00:16:42,440 --> 00:16:44,480 until the data have been analysed. 265 00:16:46,200 --> 00:16:49,520 Only then will the team know if they stand a chance 266 00:16:49,520 --> 00:16:51,320 on the real observation run... 267 00:16:52,600 --> 00:16:54,720 ..when they attempt to record 268 00:16:54,720 --> 00:16:57,040 an image of a black hole. 269 00:16:59,600 --> 00:17:01,480 An image of a black hole 270 00:17:01,480 --> 00:17:04,360 will provide a new way to test Einstein's 271 00:17:04,360 --> 00:17:06,840 most extreme theoretical predictions. 272 00:17:06,840 --> 00:17:10,520 Einstein's equations show us that if you spend an hour or two 273 00:17:10,520 --> 00:17:11,800 at the edge of a black hole, 274 00:17:11,800 --> 00:17:13,800 and then come back to Earth, for instance, 275 00:17:13,800 --> 00:17:18,360 Earth might have aged 10,000, or a million, or a billion years. 276 00:17:18,360 --> 00:17:21,800 So when we are observing the event horizon of a black hole, 277 00:17:21,800 --> 00:17:25,520 we are observing what really can be characterised as a time machine. 278 00:17:26,800 --> 00:17:29,400 Yet, despite Einstein's equations, 279 00:17:29,400 --> 00:17:32,480 even he didn't think that black holes could exist. 280 00:17:33,720 --> 00:17:36,360 That nature could ever allow them to form. 281 00:17:36,360 --> 00:17:39,120 That's a sensible objection that Einstein had. 282 00:17:39,120 --> 00:17:42,200 I mean, after all, it'd be very, very, very hard to do, 283 00:17:42,200 --> 00:17:45,720 to crush all the mass of something to a point. 284 00:17:45,720 --> 00:17:48,360 Einstein naturally and reasonably assumed 285 00:17:48,360 --> 00:17:52,360 that matter just wouldn't allow itself to be compacted that much. 286 00:17:55,040 --> 00:17:57,880 But evidence of a mechanism has been growing. 287 00:18:02,040 --> 00:18:04,200 Scientists now believe a black hole 288 00:18:04,200 --> 00:18:07,120 is the corpse of a giant star that's gone supernova. 289 00:18:12,080 --> 00:18:16,720 Deep inside the debris, the surviving core collapses 290 00:18:16,720 --> 00:18:19,080 to an infinitely small point. 291 00:18:20,360 --> 00:18:22,600 This is called the singularity. 292 00:18:24,160 --> 00:18:27,440 Its intense gravity warps space and time so severely 293 00:18:27,440 --> 00:18:32,480 that nothing can escape, forming the black hole's event horizon. 294 00:18:34,040 --> 00:18:37,240 It's possible that black holes are ultimately a figment 295 00:18:37,240 --> 00:18:40,480 of the mathematical equations that Einstein gave us, 296 00:18:40,480 --> 00:18:43,560 but how better to begin to push this understanding 297 00:18:43,560 --> 00:18:46,080 than to look and see what's actually out there? 298 00:18:46,080 --> 00:18:48,920 And that's the promise of the Event Horizon Telescope. 299 00:18:50,800 --> 00:18:54,400 The team hope to test these theories by taking a picture 300 00:18:54,400 --> 00:18:57,640 of the black hole at the centre of our galaxy. 301 00:19:00,040 --> 00:19:02,240 But they have an even bigger target, 302 00:19:02,240 --> 00:19:05,680 a black hole in the centre of a different galaxy 303 00:19:05,680 --> 00:19:07,320 called M87. 304 00:19:08,680 --> 00:19:12,640 There are only a couple of targets in the universe currently 305 00:19:12,640 --> 00:19:15,680 where the Event Horizon Telescope could hope to resolve 306 00:19:15,680 --> 00:19:19,200 this silhouette of a black hole, to see the edge of the event horizon. 307 00:19:19,200 --> 00:19:21,240 M87 is one of them. 308 00:19:21,240 --> 00:19:24,760 This image of M87 is the closest astronomers have come 309 00:19:24,760 --> 00:19:26,960 to seeing a black hole. 310 00:19:28,120 --> 00:19:31,360 But to see its edge, Shep must zoom in much further. 311 00:19:32,760 --> 00:19:36,800 If we want to image the event horizon, we have to make an image 312 00:19:36,800 --> 00:19:39,200 of what's inside this little box here 313 00:19:39,200 --> 00:19:41,720 at the very central core of this galaxy. 314 00:19:41,720 --> 00:19:44,800 That's what we've been directing all of our efforts towards 315 00:19:44,800 --> 00:19:48,840 for over a decade, to find out what happens in this place 316 00:19:48,840 --> 00:19:52,760 that has been off limits to us since the beginning of astronomy. 317 00:19:52,760 --> 00:19:54,080 If they succeed, 318 00:19:54,080 --> 00:19:57,880 computer simulations show they should see this. 319 00:19:59,280 --> 00:20:03,200 Light bent into a ring and the shadow of the black hole. 320 00:20:05,800 --> 00:20:09,520 If we can see this ring, it would be the best evidence 321 00:20:09,520 --> 00:20:12,040 that we have for the existence of black holes. 322 00:20:20,240 --> 00:20:23,640 There are now just two weeks to go until the team will attempt 323 00:20:23,640 --> 00:20:25,600 to observe the black holes 324 00:20:25,600 --> 00:20:28,720 and they're still working the problems. 325 00:20:31,640 --> 00:20:35,000 In Europe, Dutch astronomer Remo Tilanus is in charge 326 00:20:35,000 --> 00:20:37,960 of managing the logistics of this global project. 327 00:20:39,320 --> 00:20:43,120 Hey, morning. Morning. How are you guys doing? Good. Good! 328 00:20:43,120 --> 00:20:46,000 I like that, what you guys did. The monitor. 329 00:20:46,000 --> 00:20:48,400 It looks very good. Thank you. 330 00:20:50,480 --> 00:20:54,360 It's taken two months for the team to process the test run data, 331 00:20:54,360 --> 00:20:57,000 but the results are finally in. 332 00:20:57,000 --> 00:20:58,640 Hello. 333 00:20:58,640 --> 00:21:02,320 Hi! Hi. Some nice results to show you. 334 00:21:02,320 --> 00:21:06,160 The data shows the telescopes have successfully linked together. 335 00:21:06,160 --> 00:21:09,840 Even though they're apart by thousands of miles, 336 00:21:09,840 --> 00:21:13,560 they actually observed the source exactly at the same time. 337 00:21:13,560 --> 00:21:16,160 But we did have problems because the South Pole telescope, 338 00:21:16,160 --> 00:21:19,840 it has moved by about 20 metres because the whole ice sheet moves. 339 00:21:19,840 --> 00:21:22,400 That's quite unusual. I think there's no other telescope 340 00:21:22,400 --> 00:21:24,640 which does that, actually. I hope not! 341 00:21:24,640 --> 00:21:27,640 I certainly hope not. We are in trouble then, if that happens. 342 00:21:27,640 --> 00:21:29,880 That doesn't mean that the job is quite done yet. 343 00:21:29,880 --> 00:21:32,280 We have a few technical issues we need to take care of, 344 00:21:32,280 --> 00:21:34,600 but the core system works. 345 00:21:34,600 --> 00:21:37,040 It's good news for the team. 346 00:21:37,040 --> 00:21:40,800 But Heino Falcke, one of the project's leading physicists, 347 00:21:40,800 --> 00:21:44,600 knows how difficult linking all eight telescopes will be. 348 00:21:44,600 --> 00:21:47,800 If you go to these extreme experiments, 349 00:21:47,800 --> 00:21:51,000 you have to be extremely precise and take everything into account. 350 00:21:51,000 --> 00:21:54,960 You need to know the position to a fraction of a millimetre precisely. 351 00:21:54,960 --> 00:21:58,160 If you look at Hawaii, this is a volcanic region. 352 00:21:58,160 --> 00:22:00,400 This actually shifts due to plate tectonics 353 00:22:00,400 --> 00:22:03,320 by six centimetres per year. 354 00:22:03,320 --> 00:22:05,880 But, you know, if you go to the South Pole, 355 00:22:05,880 --> 00:22:07,840 there's ice and that flows, 356 00:22:07,840 --> 00:22:11,880 and this can move by metres - ten metres sometimes within years. 357 00:22:11,880 --> 00:22:15,920 So this really is the Formula 1 race car of the telescopes 358 00:22:15,920 --> 00:22:18,080 moving positions. 359 00:22:18,080 --> 00:22:20,280 And, of course, let's not forget, you know, 360 00:22:20,280 --> 00:22:22,040 away from the Earth is the moon, 361 00:22:22,040 --> 00:22:25,200 and that actually it's affecting the entire globe. 362 00:22:25,200 --> 00:22:28,200 So some of the telescopes actually will be pulled by the gravity 363 00:22:28,200 --> 00:22:30,320 of the moon into one direction. 364 00:22:30,320 --> 00:22:34,400 They move half a metre up and down every six hours. 365 00:22:34,400 --> 00:22:37,320 With such incredible precision needed, 366 00:22:37,320 --> 00:22:40,080 the team need everything to go to plan. 367 00:22:40,080 --> 00:22:44,960 Any telescope you lose will significantly compromise your result. 368 00:22:44,960 --> 00:22:46,560 It will still be interesting. 369 00:22:46,560 --> 00:22:48,240 It'll just not be an image. 370 00:22:48,240 --> 00:22:50,760 It'll be some data and some plots that you show, 371 00:22:50,760 --> 00:22:52,160 it will not be an image. 372 00:23:01,600 --> 00:23:04,280 Some of the others are very nervous, I believe, 373 00:23:04,280 --> 00:23:06,000 that they absolutely... 374 00:23:07,200 --> 00:23:09,360 ..want to get the picture this year. 375 00:23:09,360 --> 00:23:11,760 But I'm more relaxed. 376 00:23:11,760 --> 00:23:13,280 I find it exciting 377 00:23:13,280 --> 00:23:15,960 just to be at the point that we can try to do this. 378 00:23:18,640 --> 00:23:21,960 Remo has come to the Max Planck Institute for Radio Astronomy 379 00:23:21,960 --> 00:23:24,640 in Bonn to check the team's preparations. 380 00:23:26,960 --> 00:23:30,000 Here, hardware specialist Alan Roy 381 00:23:30,000 --> 00:23:33,600 is facing a problem that could jeopardise the entire project. 382 00:23:36,440 --> 00:23:37,720 Hey, Alan. 383 00:23:37,720 --> 00:23:40,560 Hi. Good to see you. Hi! How are you doing? 384 00:23:40,560 --> 00:23:43,040 Had a good trip? I had a good trip, it was fine. 385 00:23:43,040 --> 00:23:45,320 Oh, man. So it's happening here. 386 00:23:45,320 --> 00:23:46,880 So, more problems. Yeah. 387 00:23:46,880 --> 00:23:51,160 The machines that record the data are overheating. 388 00:23:51,160 --> 00:23:54,280 The problem with the recorders we have at the moment 389 00:23:54,280 --> 00:23:58,200 is they're getting too hot inside and they're shutting down. 390 00:23:58,200 --> 00:24:02,880 If that happens in the run, then that would stop us in our tracks. 391 00:24:02,880 --> 00:24:04,640 The observations we're making 392 00:24:04,640 --> 00:24:07,560 depends on having the whole array present. 393 00:24:09,280 --> 00:24:11,200 HE SPEAKS IN GERMAN 394 00:24:11,200 --> 00:24:14,520 The problem is high altitude. 395 00:24:14,520 --> 00:24:16,120 The thin air at the telescopes 396 00:24:16,120 --> 00:24:19,560 means the cooling system is less effective, 397 00:24:19,560 --> 00:24:23,200 so Alan needs to make metal plates to deflect more cool air 398 00:24:23,200 --> 00:24:24,640 over the electronics. 399 00:24:24,640 --> 00:24:26,040 No. 400 00:24:35,400 --> 00:24:37,480 So, let's see if it fits. 401 00:24:37,480 --> 00:24:39,000 It's... 402 00:24:39,000 --> 00:24:42,480 ..always a moment of tension, even in simple things. 403 00:24:42,480 --> 00:24:44,560 And, yes, perfect. 404 00:24:48,040 --> 00:24:52,800 Across the hall, Helge Rottmann is in charge of over 500 405 00:24:52,800 --> 00:24:57,760 hard drive units that can store millions of gigabytes of data. 406 00:24:57,760 --> 00:25:01,400 Disk modules, they really contain the essence of what we want to do. 407 00:25:01,400 --> 00:25:05,600 The speciality about these, they are helium-filled disks, 408 00:25:05,600 --> 00:25:07,640 able to operate at very high altitudes. 409 00:25:07,640 --> 00:25:11,640 In terms of operational costs, this is the main factor, 410 00:25:11,640 --> 00:25:14,000 so buying disks is expensive. 411 00:25:14,000 --> 00:25:17,480 For example, we cannot afford to back up any data 412 00:25:17,480 --> 00:25:19,520 and, if it gets lost or broken, 413 00:25:19,520 --> 00:25:23,120 we practically lose that data, which is quite catastrophic. 414 00:25:23,120 --> 00:25:26,760 That's my nightmare - that we'll have like a whole pallet of these 415 00:25:26,760 --> 00:25:29,960 and they drop the pallet. That is just going to be horrible. 416 00:25:31,960 --> 00:25:35,280 Remo must send the drives to each telescope location. 417 00:25:36,360 --> 00:25:40,160 It's just one small part of this global logistical feat. 418 00:25:40,160 --> 00:25:44,040 It's now 8pm and Remo is running a teleconference 419 00:25:44,040 --> 00:25:45,600 with the rest of the team. 420 00:25:45,600 --> 00:25:48,960 The next issue I think I want to tackle is the 421 00:25:48,960 --> 00:25:53,000 outstanding tickets that we have before we get to the observations. 422 00:25:53,000 --> 00:25:55,840 Just two weeks away from the observations, 423 00:25:55,840 --> 00:25:59,160 the pressures and tensions of the project are mounting. 424 00:26:00,280 --> 00:26:05,400 The schedule starts at 3pm local time, at 0100 UTC. 425 00:26:05,400 --> 00:26:07,520 There's nothing we can do about it any more. 426 00:26:07,520 --> 00:26:10,520 I mean, these were discussed and have been discussed, 427 00:26:10,520 --> 00:26:13,560 so the schedules are what they are. 428 00:26:13,560 --> 00:26:16,240 Just assume that it's going to be OK. All right. 429 00:26:16,240 --> 00:26:18,960 Nothing we can do about it. No, no, I realise that. 430 00:26:18,960 --> 00:26:20,600 OK, that's it, guys. Thanks all. 431 00:26:20,600 --> 00:26:22,000 We'll be in touch. 432 00:26:22,000 --> 00:26:23,240 OK, bye-bye. Thank, bye. 433 00:26:24,480 --> 00:26:27,720 Taking ten years to pull all these telescopes 434 00:26:27,720 --> 00:26:30,880 into the array, to equip them, 435 00:26:30,880 --> 00:26:33,320 we're all motivated by the same thing. 436 00:26:33,320 --> 00:26:37,640 We want to see that black hole and that is ultimately what drives us. 437 00:26:37,640 --> 00:26:40,280 Get a glass of wine and go to bed, 438 00:26:40,280 --> 00:26:44,240 seriously, that is what I now want to do. 439 00:27:02,680 --> 00:27:06,080 There's now just one day to go before the make or break 440 00:27:06,080 --> 00:27:08,920 observations to photograph a black hole. 441 00:27:10,360 --> 00:27:13,040 So move it here. 442 00:27:13,040 --> 00:27:15,680 Imagine we had it kind of open... 443 00:27:15,680 --> 00:27:19,640 In Massachusetts, Shep and physicist Demetrius Soltis 444 00:27:19,640 --> 00:27:22,480 are setting up a central communications hub. 445 00:27:22,480 --> 00:27:27,960 Yeah. To have space around, something like that. 446 00:27:27,960 --> 00:27:30,240 What do you say? Now you're talking. 447 00:27:30,240 --> 00:27:31,600 Now you're talking. 448 00:27:31,600 --> 00:27:33,680 This will be mission control. 449 00:27:34,960 --> 00:27:37,520 Communication is vital to the entire project. 450 00:27:37,520 --> 00:27:40,560 I mean, we're synchronising things to a microsecond. 451 00:27:40,560 --> 00:27:42,840 We need to make sure that everything is set up. 452 00:27:42,840 --> 00:27:45,240 We need to make sure all the tests have been run. 453 00:27:48,800 --> 00:27:52,240 The team need to link eight world leading multi-million dollar 454 00:27:52,240 --> 00:27:55,320 observatories simultaneously to capture that image. 455 00:27:57,080 --> 00:27:58,960 We've got clear blue skies, so... 456 00:27:58,960 --> 00:28:01,560 They have a ten-day window at the telescopes, 457 00:28:01,560 --> 00:28:04,760 but clouds at any one of them could obscure the signal 458 00:28:04,760 --> 00:28:07,360 from the black hole and ruin the data. 459 00:28:09,320 --> 00:28:11,920 So, each day, Shep needs to make a call. 460 00:28:11,920 --> 00:28:14,960 If the night is "go" or "no go". 461 00:28:14,960 --> 00:28:19,320 Whether or not you energise the Event Horizon Telescope on any given night, 462 00:28:19,320 --> 00:28:21,680 that's the biggest decision you can make. 463 00:28:21,680 --> 00:28:24,280 If you make the right one then you've got great data. 464 00:28:24,280 --> 00:28:26,160 If you make a wrong decision, 465 00:28:26,160 --> 00:28:29,600 you've expended huge amounts of resources. 466 00:28:29,600 --> 00:28:34,040 Each night of observation will not only cost thousands of pounds, 467 00:28:34,040 --> 00:28:37,320 but also eat up their limited hard drive space. 468 00:28:37,320 --> 00:28:39,160 Shep needs five nights of data 469 00:28:39,160 --> 00:28:41,760 to stand the best chance of making an image. 470 00:28:43,560 --> 00:28:48,040 Judging the weather conditions across the world will be critical. 471 00:28:48,040 --> 00:28:50,680 It might go above in the next couple of days. 472 00:28:50,680 --> 00:28:52,400 That looks good. 473 00:28:52,400 --> 00:28:54,600 If you make the wrong "go" or "no go" decision, 474 00:28:54,600 --> 00:28:58,320 you may have jeopardised your ability to image a black hole 475 00:28:58,320 --> 00:29:01,960 and that's what consumes us when we're in that room. 476 00:29:01,960 --> 00:29:04,520 Hey, Kazu. 477 00:29:04,520 --> 00:29:07,520 The communication and weather reports are online. 478 00:29:07,520 --> 00:29:10,800 Now Shep needs to make sure the telescopes are ready. 479 00:29:10,800 --> 00:29:13,280 We want to make sure that we understand where things stand 480 00:29:13,280 --> 00:29:15,240 by the end of today because if something 481 00:29:15,240 --> 00:29:18,000 is not technically ready, then we really do have a problem. 482 00:29:24,280 --> 00:29:29,120 In Hawaii, the volcano Mauna Kea is home to two observatories 483 00:29:29,120 --> 00:29:30,640 in the network. 484 00:29:32,120 --> 00:29:35,160 The James Clerk Maxwell Telescope 485 00:29:35,160 --> 00:29:37,000 and the Submillimeter Array. 486 00:29:39,920 --> 00:29:44,560 Remo has arrived from Europe, but the equipment still isn't ready. 487 00:29:49,280 --> 00:29:51,120 Hey, Jonathan. Oh, hi, Remo. 488 00:29:51,120 --> 00:29:53,080 How's it going? Not too bad. 489 00:29:53,080 --> 00:29:55,960 Lead engineer Jonathan Weintroub 490 00:29:55,960 --> 00:30:00,720 is still fitting the new cooling kits to his set of data recorders. 491 00:30:00,720 --> 00:30:03,280 It was installed on Thursday and then we were like, 492 00:30:03,280 --> 00:30:05,640 "Oh, damn, it doesn't have a cooling kit." 493 00:30:05,640 --> 00:30:08,120 Yeah. So we're putting in the... 494 00:30:08,120 --> 00:30:11,000 Right, so proper just in time management, I guess. 495 00:30:11,000 --> 00:30:13,800 I guess, yeah. This is kind of last minute. 496 00:30:15,240 --> 00:30:17,320 This is kind of preventative maintenance - 497 00:30:17,320 --> 00:30:21,560 we don't want to suffer a failure due to overheating 498 00:30:21,560 --> 00:30:23,480 in the middle of the run. 499 00:30:23,480 --> 00:30:27,040 Yeah. Now the light turned on. Here we go. Yeah. 500 00:30:27,040 --> 00:30:30,200 And there's air blowing out of these fans, so... Yup. 501 00:30:30,200 --> 00:30:31,880 Excellent. 502 00:30:39,080 --> 00:30:42,000 Remo and Jonathan must install the recorders 503 00:30:42,000 --> 00:30:43,720 and check they're all working. 504 00:30:43,720 --> 00:30:46,480 All right. There we go. That's it. 505 00:30:48,560 --> 00:30:51,200 Yep, all of them show up. Right. 506 00:30:51,200 --> 00:30:54,000 The very act of powering down and then powering up 507 00:30:54,000 --> 00:30:55,760 is to some degree stressful. 508 00:30:57,200 --> 00:31:02,640 Sometimes you power something down and it never works again, so... 509 00:31:02,640 --> 00:31:04,960 ..you're always relieved when something works. 510 00:31:09,880 --> 00:31:12,880 Whilst things are back on track in Hawaii... 511 00:31:14,440 --> 00:31:16,960 ..high in the Atacama Desert of Chile... 512 00:31:19,520 --> 00:31:25,080 ..Alan Roy has arrived from Germany to lead the observations at Apex. 513 00:31:25,080 --> 00:31:27,960 Control, Apex boss... 514 00:31:27,960 --> 00:31:33,920 Here, Alan is responsible for the most critical part of the project - 515 00:31:33,920 --> 00:31:35,160 the timing. 516 00:31:35,160 --> 00:31:37,560 Timing is absolutely important to this project - 517 00:31:37,560 --> 00:31:42,200 absolutely central - it's the heart piece of the whole experiment. 518 00:31:42,200 --> 00:31:45,520 You're putting in a lot of effort, a lot of money, a lot of time, 519 00:31:45,520 --> 00:31:48,880 and it's all hinging on getting the timing right. 520 00:31:51,440 --> 00:31:54,320 The Event Horizon Telescope network is so large, 521 00:31:54,320 --> 00:31:58,160 the emission from the black hole will arrive at each telescope 522 00:31:58,160 --> 00:32:00,600 at a different point in time. 523 00:32:00,600 --> 00:32:03,920 What's more, the Earth rotates. 524 00:32:03,920 --> 00:32:07,520 As it spins, the position of the telescopes in space 525 00:32:07,520 --> 00:32:09,520 constantly changes. 526 00:32:09,520 --> 00:32:13,240 If the team can't record the time the signals arrive 527 00:32:13,240 --> 00:32:15,920 to within a millionth of a millionth of a second, 528 00:32:15,920 --> 00:32:19,560 the telescopes will fail to combine as one. 529 00:32:22,400 --> 00:32:26,320 To sync the telescopes together, the team have spent $2 million 530 00:32:26,320 --> 00:32:29,600 on some of the most accurate atomic clocks in the world, 531 00:32:29,600 --> 00:32:31,720 called hydrogen masers. 532 00:32:32,920 --> 00:32:34,600 This is the hydrogen maser. 533 00:32:34,600 --> 00:32:39,120 This clock keeps time to about a second in ten million years. 534 00:32:39,120 --> 00:32:41,600 Of course, we don't wait ten million years to measure it. 535 00:32:41,600 --> 00:32:44,400 Alan must keep this clock at a stable temperature 536 00:32:44,400 --> 00:32:46,120 so it can run precisely. 537 00:32:47,440 --> 00:32:49,000 But there's a problem. 538 00:32:49,000 --> 00:32:52,120 The chamber used to cool it is broken. 539 00:32:52,120 --> 00:32:55,280 The bearings have seized and we've got no cooling, 540 00:32:55,280 --> 00:32:57,960 so that means the chamber overheats 541 00:32:57,960 --> 00:33:00,400 and the maser is then not very happy. 542 00:33:00,400 --> 00:33:03,160 A faulty maser could be catastrophic. 543 00:33:06,400 --> 00:33:08,360 In the remote Atacama Desert, 544 00:33:08,360 --> 00:33:10,800 it's too far to call out an engineer. 545 00:33:10,800 --> 00:33:14,160 Alan has only one improvised option available. 546 00:33:14,160 --> 00:33:19,280 The solution is to crack open the door of the chamber 547 00:33:19,280 --> 00:33:22,320 so the excess heat from the maser can come out through the door. 548 00:33:23,960 --> 00:33:28,560 Makes me a little nervous, but the clock we have to take on faith, yes, 549 00:33:28,560 --> 00:33:30,400 that it's running as it should. 550 00:33:30,400 --> 00:33:33,600 For now, this resourceful solution 551 00:33:33,600 --> 00:33:36,040 has to keep the clock running correctly, 552 00:33:36,040 --> 00:33:38,840 or the whole experiment could be at risk. 553 00:33:38,840 --> 00:33:44,720 My hat is off to the folks that can actually undertake these experiments 554 00:33:44,720 --> 00:33:47,080 and observations, and make it work. 555 00:33:47,080 --> 00:33:48,880 It's real, it's tangible, 556 00:33:48,880 --> 00:33:51,760 and it's extreme and abstract at the same time. 557 00:33:56,040 --> 00:33:58,760 There's always a risk with these kind of measurements. 558 00:33:58,760 --> 00:34:00,320 They're difficult things. 559 00:34:00,320 --> 00:34:03,520 It requires so much care and finesse 560 00:34:03,520 --> 00:34:05,280 to bring all these pieces together. 561 00:34:08,440 --> 00:34:12,800 Remarkably, the weather is clear at all eight telescopes. 562 00:34:12,800 --> 00:34:16,400 In Hawaii, Remo hears from mission control. 563 00:34:17,760 --> 00:34:20,600 So, just got the news, good to go. 564 00:34:20,600 --> 00:34:24,320 So, ready to go and start observing. 565 00:34:26,720 --> 00:34:28,760 This is the crucial moment 566 00:34:28,760 --> 00:34:32,400 that over ten years of hard work has been leading up to. 567 00:34:32,400 --> 00:34:35,120 It's taken a long time to get to this point 568 00:34:35,120 --> 00:34:38,880 that we going to give it a real shot to get an image of a black hole 569 00:34:38,880 --> 00:34:41,760 and now, finally, the day is here. 570 00:34:44,000 --> 00:34:47,440 Remo must ascend to over 4,000 metres, 571 00:34:47,440 --> 00:34:49,640 to the top of the volcano. 572 00:34:51,040 --> 00:34:52,360 Here, two observatories, 573 00:34:52,360 --> 00:34:54,920 the James Clerk Maxwell Telescope, 574 00:34:54,920 --> 00:34:57,400 and the Submillimeter Array, 575 00:34:57,400 --> 00:34:59,360 are part of the network. 576 00:35:00,800 --> 00:35:02,960 Remo is up against the clock. 577 00:35:06,320 --> 00:35:07,760 Right... 578 00:35:10,600 --> 00:35:13,160 We have to start tuning the receiver. 579 00:35:13,160 --> 00:35:17,880 This mirror directs the radiation into the receiver that we'll use. 580 00:35:17,880 --> 00:35:20,040 It's like tuning a radio. 581 00:35:21,120 --> 00:35:22,560 That's going. 582 00:35:22,560 --> 00:35:24,760 Looking good. 583 00:35:24,760 --> 00:35:26,480 At the Submillimeter Array, 584 00:35:26,480 --> 00:35:30,560 engineer Jonathan Weintroub is in charge of recording the data. 585 00:35:30,560 --> 00:35:34,000 We have 50 minutes now to run the checks 586 00:35:34,000 --> 00:35:36,400 before we start recording 587 00:35:36,400 --> 00:35:39,880 and high altitude doesn't help your brain function. 588 00:35:39,880 --> 00:35:43,320 You tend to make more mistakes at altitude. 589 00:35:43,320 --> 00:35:47,040 But, across the mountain, Remo hits a glitch. 590 00:35:47,040 --> 00:35:48,200 Oh! 591 00:35:49,600 --> 00:35:50,800 What the heck? 592 00:35:50,800 --> 00:35:52,440 He fell out of lock. 593 00:35:52,440 --> 00:35:55,680 The receiver won't lock onto the frequency. 594 00:35:57,440 --> 00:36:01,760 Without a lock, the data from the telescope will be ruined. 595 00:36:06,280 --> 00:36:10,880 Remo has no option but to manually adjust the receiver settings. 596 00:36:10,880 --> 00:36:12,320 Done. 597 00:36:12,320 --> 00:36:14,640 I need reading glasses. 598 00:36:14,640 --> 00:36:16,960 I can't see the stupid dials any more! 599 00:36:21,880 --> 00:36:23,640 Yes, it stayed on lock. 600 00:36:23,640 --> 00:36:25,280 Excellent. 601 00:36:28,760 --> 00:36:29,880 All right. 602 00:36:29,880 --> 00:36:31,920 The team is ready just in time. 603 00:36:31,920 --> 00:36:34,720 We're all set. Good. 604 00:36:35,880 --> 00:36:37,800 Great, it has a nice signal. 605 00:36:39,320 --> 00:36:42,600 Attention! Doors and roof will be opening! 606 00:36:42,600 --> 00:36:44,880 Doors and roof will be opening. 607 00:36:44,880 --> 00:36:47,840 Station 42. Station 42. 608 00:36:53,960 --> 00:36:55,840 It's opening. 609 00:37:01,320 --> 00:37:03,800 Remo directs the dish onto the target. 610 00:37:05,760 --> 00:37:08,600 Jonathan gets ready to record the data. 611 00:37:08,600 --> 00:37:12,640 Five, four, three, two, one. 612 00:37:12,640 --> 00:37:14,480 Are we going? 613 00:37:14,480 --> 00:37:18,040 The Event Horizon Telescope is on the way. 614 00:37:19,320 --> 00:37:21,520 After over ten years of work, 615 00:37:21,520 --> 00:37:24,640 the teams at eight different observatories 616 00:37:24,640 --> 00:37:28,120 are finally fixing their gaze on a black hole. 617 00:37:36,480 --> 00:37:39,720 The team observe the emission from black holes M87 618 00:37:39,720 --> 00:37:43,320 and Sagittarius A-star, and record data late into the night. 619 00:37:44,760 --> 00:37:49,600 After a 14-hour shift, Remo must leave to avoid altitude sickness. 620 00:37:49,600 --> 00:37:53,120 It's getting close to our 14 hours on the mountain. 621 00:37:53,120 --> 00:37:56,560 Getting tired, and I will go down to the day facility, which is 622 00:37:56,560 --> 00:37:57,800 a little bit lower, 623 00:37:57,800 --> 00:38:01,360 but I will be sitting and monitoring there for quite a few more hours. 624 00:38:01,360 --> 00:38:06,080 But at least there will be more oxygen there, so that will help. 625 00:38:06,080 --> 00:38:08,800 Thank you for the support. Good luck for the rest of the night. 626 00:38:08,800 --> 00:38:11,320 We'll see you tomorrow. All right? Cheers. 627 00:38:13,080 --> 00:38:15,040 Over the first two days of the run, 628 00:38:15,040 --> 00:38:17,320 the eight telescopes around the world 629 00:38:17,320 --> 00:38:19,640 record two full nights of data. 630 00:38:23,760 --> 00:38:26,080 But in these extreme locations, the physical, 631 00:38:26,080 --> 00:38:27,880 as well as the mental, challenges 632 00:38:27,880 --> 00:38:30,280 are taking their toll on the team. 633 00:38:33,360 --> 00:38:34,920 It's hard physical work each day, 634 00:38:34,920 --> 00:38:37,040 and you feel it constantly on your body, 635 00:38:37,040 --> 00:38:39,720 the pulse rate is constantly elevated at altitude. 636 00:38:39,720 --> 00:38:41,400 Constant stress on the system. 637 00:38:44,040 --> 00:38:45,600 We're tired. 638 00:38:45,600 --> 00:38:49,640 You know, you wind up just being up at all hours of the night. 639 00:38:49,640 --> 00:38:52,280 People at high altitude are not always thinking perfectly. 640 00:38:52,280 --> 00:38:54,320 Where is it? Where is this? 641 00:38:54,320 --> 00:38:57,040 Oh, so it's in front... Oh. 642 00:38:57,040 --> 00:38:59,200 We had a problem at one of the telescopes, 643 00:38:59,200 --> 00:39:02,000 one of the bits of electronics that we rely on 644 00:39:02,000 --> 00:39:03,840 was giving us some crazy results. 645 00:39:03,840 --> 00:39:05,600 We're at the maser right now. 646 00:39:05,600 --> 00:39:07,840 Look at channel number 17. 647 00:39:07,840 --> 00:39:12,680 And ultimately we fixed it because we were in the room, we're working. 648 00:39:16,640 --> 00:39:20,040 So far, the weather has been perfect across the globe. 649 00:39:20,040 --> 00:39:24,240 But on day three, at the Large Millimetre Telescope in Mexico, 650 00:39:24,240 --> 00:39:26,720 the outlook is beginning to change. 651 00:39:26,720 --> 00:39:30,560 That's a scary, scary webcam. 652 00:39:31,920 --> 00:39:34,920 The LMT is just completely chaotic right now. 653 00:39:34,920 --> 00:39:39,160 I mean, you saw the webcam. There's fog, there's clouds rolling in, 654 00:39:39,160 --> 00:39:42,840 it looks very, very dicey up there. 655 00:39:42,840 --> 00:39:45,080 It's clearly building up. 656 00:39:54,760 --> 00:39:57,160 I mean, I'm not going to candy coat it for you, guys. 657 00:39:57,160 --> 00:40:01,240 The decision for tonight largely rests with you, 658 00:40:01,240 --> 00:40:03,600 whether we go or not. 659 00:40:03,600 --> 00:40:05,520 It's a fool's game, right? 660 00:40:05,520 --> 00:40:08,600 You can't predict the weather ten hours from now, 661 00:40:08,600 --> 00:40:10,760 especially the top of an extinct volcano 662 00:40:10,760 --> 00:40:12,640 with a big telescope on it. 663 00:40:12,640 --> 00:40:17,640 We've got real solid good weather at one, two, three, four, five, 664 00:40:17,640 --> 00:40:19,360 six of our sites. 665 00:40:19,360 --> 00:40:21,160 Six out of eight. 666 00:40:21,160 --> 00:40:24,520 Those are tremendous, tremendous odds. 667 00:40:24,520 --> 00:40:27,520 Two of the key sites, they're marginal. 668 00:40:28,640 --> 00:40:31,120 The telescope in Mexico, the LMT, 669 00:40:31,120 --> 00:40:33,440 and the telescope in Arizona, 670 00:40:33,440 --> 00:40:36,040 have dicey weather 671 00:40:36,040 --> 00:40:38,240 and so we're just going to wait. 672 00:40:40,760 --> 00:40:43,440 Shep delays the "go", "no-go" decision. 673 00:40:44,440 --> 00:40:46,160 It's too close to call. 674 00:40:46,160 --> 00:40:50,800 You guys have to explain these LMT webcams to me - from one direction, 675 00:40:50,800 --> 00:40:53,600 it just looks like a vacation paradise. 676 00:40:55,040 --> 00:40:56,640 And then these other views, 677 00:40:56,640 --> 00:41:02,000 it just looks like you're heading into a vortex maelstrom of hell, 678 00:41:02,000 --> 00:41:06,440 and I don't understand how three different views can be so different. 679 00:41:07,880 --> 00:41:09,600 Shep has to decide. 680 00:41:09,600 --> 00:41:13,400 But now there's news from the ALMA observatory in Chile. 681 00:41:13,400 --> 00:41:14,800 Hold on, hold on. 682 00:41:14,800 --> 00:41:17,240 I want to make sure I understand what you just said. 683 00:41:18,560 --> 00:41:20,040 You think there's a chance 684 00:41:20,040 --> 00:41:23,920 that the data from last night from Alma are corrupted? 685 00:41:25,280 --> 00:41:26,640 Um, there's a chance. 686 00:41:29,560 --> 00:41:33,440 Their entire second night of data could be corrupt. 687 00:41:35,320 --> 00:41:37,880 This is a whole new wrinkle for us. 688 00:41:37,880 --> 00:41:42,160 If you had extra time, could you run this problem down? 689 00:41:42,160 --> 00:41:45,080 Running it down is probably not likely. 690 00:41:46,400 --> 00:41:48,080 If the data are corrupt, 691 00:41:48,080 --> 00:41:52,000 the team might now only have one night out of the five they need. 692 00:41:54,400 --> 00:41:58,240 With the weather set to get worse, Shep has to take a risk. 693 00:41:58,240 --> 00:42:01,480 I think we should make this a go because we're not going to 694 00:42:01,480 --> 00:42:05,640 tear the system apart, so we have to assume that ALMA will be fine. 695 00:42:05,640 --> 00:42:08,400 So I'm going to say that we're going to go. 696 00:42:14,480 --> 00:42:18,120 Over the next four days, the team let the storm pass 697 00:42:18,120 --> 00:42:20,560 and observe for another two nights. 698 00:42:21,640 --> 00:42:23,800 We are observing the data. 699 00:42:26,680 --> 00:42:29,680 Their hard drives fill up with over six million gigabytes 700 00:42:29,680 --> 00:42:31,120 of precious data - 701 00:42:31,120 --> 00:42:35,000 more storage than 12,000 laptop computers. 702 00:42:39,840 --> 00:42:41,720 If the team can make an image, 703 00:42:41,720 --> 00:42:45,160 it could unravel one of the biggest mysteries of physics today... 704 00:42:51,680 --> 00:42:54,760 ..what lies at the very centre of a black hole. 705 00:42:57,320 --> 00:43:00,000 Einstein's equations suggest it's an infinitely small 706 00:43:00,000 --> 00:43:01,400 and dense point - 707 00:43:01,400 --> 00:43:03,520 the so-called singularity. 708 00:43:05,080 --> 00:43:07,960 A singularity is a physicist's way of saying, 709 00:43:07,960 --> 00:43:10,600 "We do not know what the heck is going on." 710 00:43:10,600 --> 00:43:14,120 In reality, at the dense core of a black hole, 711 00:43:14,120 --> 00:43:17,040 Einstein's equations don't make sense. 712 00:43:18,480 --> 00:43:21,360 If you take Einstein's mathematics seriously 713 00:43:21,360 --> 00:43:23,960 and apply it right to the centre of a black hole, 714 00:43:23,960 --> 00:43:26,240 then you do have infinite density. 715 00:43:26,240 --> 00:43:30,000 But there's no meter in the world that, 716 00:43:30,000 --> 00:43:32,440 when you measure something, goes, "Infinity!" 717 00:43:35,800 --> 00:43:39,800 Nature is kind of grabbing us by the lapel and slapping us 718 00:43:39,800 --> 00:43:43,240 in the face and saying, "You don't understand what you're doing 719 00:43:43,240 --> 00:43:46,160 "if infinity is cropping up as the answer." 720 00:43:46,160 --> 00:43:50,760 Right now, frankly, the interior of a black hole 721 00:43:50,760 --> 00:43:53,280 is the Wild West of physics theorists. 722 00:43:53,280 --> 00:43:54,720 But the good news is, 723 00:43:54,720 --> 00:43:58,120 if you have a theory that predicts something different from Einstein 724 00:43:58,120 --> 00:44:01,200 for what happens inside, there's a good chance it also predicts 725 00:44:01,200 --> 00:44:04,000 something different from what happens immediately outside. 726 00:44:04,000 --> 00:44:08,240 It's so exciting to finally, hopefully, start getting some clues 727 00:44:08,240 --> 00:44:10,640 from the Event Horizon Telescope. 728 00:44:12,320 --> 00:44:16,000 A picture of a black hole will take theory into reality. 729 00:44:16,000 --> 00:44:20,320 It could be the best physical evidence scientists have 730 00:44:20,320 --> 00:44:23,480 to figure out the mysteries deep inside 731 00:44:23,480 --> 00:44:27,720 and could pave the way to a so-called theory of everything. 732 00:44:35,920 --> 00:44:38,400 It's seven days into the run. 733 00:44:43,200 --> 00:44:45,040 At mission control, 734 00:44:45,040 --> 00:44:48,040 the team must now decide on what could be 735 00:44:48,040 --> 00:44:50,000 the final night of observation. 736 00:44:50,000 --> 00:44:51,480 This will be our fifth night. 737 00:44:51,480 --> 00:44:54,400 This way, we'll have Apex and ALMA 738 00:44:54,400 --> 00:44:56,960 at one end of a very sensitive baseline, 739 00:44:56,960 --> 00:45:00,040 with really good weather at the other end of the baseline. 740 00:45:00,040 --> 00:45:02,640 The weather looks clear around the world. 741 00:45:03,920 --> 00:45:05,520 All right, so we're a go for tonight. 742 00:45:05,520 --> 00:45:07,960 Everybody, let's make it count. 743 00:45:18,040 --> 00:45:19,400 For the last time, 744 00:45:19,400 --> 00:45:22,560 light from around the black holes is being recorded. 745 00:45:25,760 --> 00:45:28,360 In Chile, Alan Roy and the team 746 00:45:28,360 --> 00:45:31,160 finish what's been a tiring eight days. 747 00:45:31,160 --> 00:45:33,840 This is coming up to the end of the last run. 748 00:45:33,840 --> 00:45:35,960 We've got maybe three minutes. 749 00:45:35,960 --> 00:45:38,040 I'm feeling weary, but content. 750 00:45:39,200 --> 00:45:42,800 The team have recorded their target of five nights of data, 751 00:45:42,800 --> 00:45:46,080 but only when they combine all the data together 752 00:45:46,080 --> 00:45:49,280 will they know if they can see a black hole. 753 00:45:50,320 --> 00:45:54,600 This is the interesting part, it's almost a game of bluff. 754 00:45:55,800 --> 00:45:58,480 You've now spent more than a week here, 755 00:45:58,480 --> 00:46:00,880 the telescope's observed through the night, 756 00:46:00,880 --> 00:46:03,760 and we still don't know if anything will come out of this. 757 00:46:09,880 --> 00:46:13,160 Back at mission control, Shep is reflecting on the team's 758 00:46:13,160 --> 00:46:15,440 extraordinary accomplishment. 759 00:46:15,440 --> 00:46:18,240 This is the beginning of the end, right? 760 00:46:18,240 --> 00:46:22,080 I mean, this is not the end by any stretch of the imagination. 761 00:46:24,840 --> 00:46:28,600 Even though we have all these disks, they could get lost in the mail. 762 00:46:28,600 --> 00:46:30,480 There are no back-ups. 763 00:46:30,480 --> 00:46:32,840 It's very, very difficult to copy all this data. 764 00:46:32,840 --> 00:46:36,720 So, we're just a little nervous about some of that. 765 00:46:38,440 --> 00:46:41,600 You know, we have a lot of work to do. A lot of work to do. 766 00:46:41,600 --> 00:46:44,040 But we've taken this first big step. 767 00:46:48,360 --> 00:46:52,600 We humans love exploring things to the limits of what's possible 768 00:46:52,600 --> 00:46:55,200 and the event horizon is the ultimate limit. 769 00:46:55,200 --> 00:46:58,840 I look at the audacity and the bravery, frankly, 770 00:46:58,840 --> 00:47:01,360 of the people who came up with a way 771 00:47:01,360 --> 00:47:03,520 of actually taking this incredible challenge 772 00:47:03,520 --> 00:47:07,480 and turning it into something that they are measuring today. 773 00:47:07,480 --> 00:47:08,600 It's mind-boggling. 774 00:47:19,720 --> 00:47:24,240 At the South Pole, after five months of winter darkness, 775 00:47:24,240 --> 00:47:26,240 flights resume once again. 776 00:47:31,600 --> 00:47:34,600 Now the team can ship the last remaining hard drives 777 00:47:34,600 --> 00:47:36,480 holding the precious black hole data 778 00:47:36,480 --> 00:47:38,720 back to Massachusetts and Germany, 779 00:47:38,720 --> 00:47:43,560 and complete the processing from all eight telescopes. 780 00:47:43,560 --> 00:47:45,960 This is where a lot of the action has been 781 00:47:45,960 --> 00:47:49,240 because all the drives that you see here 782 00:47:49,240 --> 00:47:51,120 came from all over the globe, 783 00:47:51,120 --> 00:47:54,080 all the sites have sent their drives here, 784 00:47:54,080 --> 00:47:56,160 and this correlator has been crunching through 785 00:47:56,160 --> 00:47:58,440 all of these drives. 786 00:47:58,440 --> 00:48:01,000 Five months since the observations, 787 00:48:01,000 --> 00:48:05,520 the team can finally see if the telescopes linked together. 788 00:48:05,520 --> 00:48:07,440 This one's from Spain. 789 00:48:07,440 --> 00:48:09,360 This one's from Hawaii. 790 00:48:09,360 --> 00:48:10,920 This one's from Mexico. 791 00:48:10,920 --> 00:48:15,240 So you're really seeing, kind of, a UN of the astronomy world here. 792 00:48:15,240 --> 00:48:19,320 We're basically taking the light that was recorded from these sites 793 00:48:19,320 --> 00:48:21,240 out of the deep freeze, 794 00:48:21,240 --> 00:48:23,800 re-animating it, and then combining it 795 00:48:23,800 --> 00:48:27,680 as though it was being combined for the first time. 796 00:48:27,680 --> 00:48:31,720 But data expert Vincent Fish finds a problem with the timing. 797 00:48:32,760 --> 00:48:34,560 This is... This cannot be right. 798 00:48:34,560 --> 00:48:36,360 BLEEP 799 00:48:36,360 --> 00:48:37,840 I'm... I'm amazed that nobody... 800 00:48:37,840 --> 00:48:40,240 Hold on, hold on. 801 00:48:40,240 --> 00:48:42,360 Oh, sweet Jesus. 802 00:48:46,320 --> 00:48:48,960 They have discovered one of the network's atomic clocks 803 00:48:48,960 --> 00:48:51,040 in Spain was faulty. 804 00:48:51,040 --> 00:48:53,840 You're really getting just random noise here. 805 00:48:53,840 --> 00:48:55,320 Yeah. OK. 806 00:48:55,320 --> 00:48:58,920 We're pushing really the recording, 807 00:48:58,920 --> 00:49:01,040 and the technology, 808 00:49:01,040 --> 00:49:03,560 and the resolution to its absolute limits. 809 00:49:03,560 --> 00:49:06,400 And when you push something to the limits like this, 810 00:49:06,400 --> 00:49:08,840 you start uncovering these problems. 811 00:49:08,840 --> 00:49:10,960 There is a fix to this. 812 00:49:10,960 --> 00:49:12,560 I think we can correct for it, 813 00:49:12,560 --> 00:49:14,840 so we don't face this problem again. 814 00:49:14,840 --> 00:49:18,240 Wow, look at this. This is the... 815 00:49:19,880 --> 00:49:20,960 ..the delay. 816 00:49:22,080 --> 00:49:24,800 Whilst the team resolve the timing glitches... 817 00:49:28,000 --> 00:49:32,160 ..in Cambridge, scientists from Arizona, Europe and Japan 818 00:49:32,160 --> 00:49:35,880 have come to test how to turn the new data into images. 819 00:49:35,880 --> 00:49:37,720 The big challenge that we face 820 00:49:37,720 --> 00:49:40,400 in this technique of the Event Horizon Telescope 821 00:49:40,400 --> 00:49:43,360 is that we don't have all the pixels in the image, if you will. 822 00:49:43,360 --> 00:49:44,760 We have some of the pixels. 823 00:49:44,760 --> 00:49:48,760 So the art is trying to figure out what the entire image looks like 824 00:49:48,760 --> 00:49:52,480 without having, you know, everything that we'd like to have. 825 00:49:53,800 --> 00:49:56,600 The team will test different computer algorithms 826 00:49:56,600 --> 00:49:59,640 to see if they can create an accurate image, 827 00:49:59,640 --> 00:50:03,280 but they won't attempt it on the target black holes just yet. 828 00:50:04,360 --> 00:50:06,960 First, we're putting on training wheels, right? 829 00:50:06,960 --> 00:50:08,520 We're taking baby steps 830 00:50:08,520 --> 00:50:12,320 and we're trying to use the algorithms that we want to use 831 00:50:12,320 --> 00:50:14,640 for Sagittarius A-star and M87, 832 00:50:14,640 --> 00:50:17,760 but on well-known sources that are much brighter. 833 00:50:19,400 --> 00:50:22,680 These bright sources come from matter swirling into what's believed 834 00:50:22,680 --> 00:50:24,560 to be a feasting black hole. 835 00:50:26,840 --> 00:50:30,720 As the black hole accelerates the matter, it rips it apart... 836 00:50:31,800 --> 00:50:34,400 ..and launches jets of radiation into space. 837 00:50:35,840 --> 00:50:37,440 These are quasars. 838 00:50:38,680 --> 00:50:41,520 They can kick out more energy than a billion stars, 839 00:50:41,520 --> 00:50:45,760 leaving a signature jet that's visible across the cosmos. 840 00:50:47,840 --> 00:50:52,040 If we can get really good images on those sources, 841 00:50:52,040 --> 00:50:55,400 then we know we'll be ready to go to the next phase. 842 00:50:56,920 --> 00:51:00,080 Imaging scientist Katie Bouman is leading one of the teams 843 00:51:00,080 --> 00:51:02,200 trying to make an image of the quasar. 844 00:51:02,200 --> 00:51:03,480 It's really exciting - 845 00:51:03,480 --> 00:51:06,400 the first time we're actually trying to make an image with the data. 846 00:51:07,480 --> 00:51:09,080 So here is 120... 847 00:51:09,080 --> 00:51:12,840 The quasar is too far away to see the black hole itself. 848 00:51:14,480 --> 00:51:16,960 But the team know what the jet should look like 849 00:51:16,960 --> 00:51:18,640 from existing telescopes. 850 00:51:23,080 --> 00:51:25,400 But, two days into this workshop, 851 00:51:25,400 --> 00:51:29,040 the algorithms are not producing one consistent image. 852 00:51:30,560 --> 00:51:34,680 I can make an image that looks like that and that's ridiculous. 853 00:51:34,680 --> 00:51:37,280 We get a lot of different kind of structures come out 854 00:51:37,280 --> 00:51:38,480 from the same data - 855 00:51:38,480 --> 00:51:42,040 that's not a vote of confidence in those images, I guess. 856 00:51:42,040 --> 00:51:46,480 Physicist Mareki Honma is also not getting a clear image. 857 00:51:46,480 --> 00:51:48,240 Here, it's a very bright spot, 858 00:51:48,240 --> 00:51:50,600 so we believe there is something. 859 00:51:50,600 --> 00:51:52,000 But the whole area, 860 00:51:52,000 --> 00:51:54,640 it just looks like noise. 861 00:52:01,840 --> 00:52:05,400 If the team can't get the algorithms to work for the quasar, 862 00:52:05,400 --> 00:52:08,200 they won't be able to make an image of the black hole. 863 00:52:15,360 --> 00:52:18,520 The team work for a week adjusting the computer code. 864 00:52:20,040 --> 00:52:22,920 Finally, the algorithms start to work. 865 00:52:24,080 --> 00:52:28,720 And the team can see the quasar jet in more detail than ever before. 866 00:52:28,720 --> 00:52:32,640 I see this jet-like kind of structure shooting out. 867 00:52:32,640 --> 00:52:34,680 It's... It's incredible. 868 00:52:34,680 --> 00:52:36,760 Look at all the structure. 869 00:52:36,760 --> 00:52:39,120 The team has produced images now, 870 00:52:39,120 --> 00:52:42,840 after going through this whole pipeline, that seem very robust. 871 00:52:43,960 --> 00:52:45,240 So that's the key. 872 00:52:45,240 --> 00:52:47,400 You have to be so confident in your techniques 873 00:52:47,400 --> 00:52:50,680 and your data handling that you trust them 874 00:52:50,680 --> 00:52:53,360 because for Sag A-star, or for M87, 875 00:52:53,360 --> 00:52:55,200 we have no idea what we're going to see. 876 00:52:59,080 --> 00:53:01,080 After over ten years of planning... 877 00:53:01,080 --> 00:53:03,280 Lights. Yes! 878 00:53:04,880 --> 00:53:06,800 ...over £30 million, 879 00:53:06,800 --> 00:53:11,440 and the combined brainpower of over 200 international scientists... 880 00:53:11,440 --> 00:53:14,800 Attention, attention! Doors and roof will be opening. 881 00:53:16,280 --> 00:53:19,120 Control, Apex boss... 882 00:53:19,120 --> 00:53:24,200 ..finally, the time comes to try and make an image of a black hole. 883 00:53:24,200 --> 00:53:28,280 This has been a huge process, a very, very careful process, 884 00:53:28,280 --> 00:53:32,360 and the imaging team is now getting the first set of data they can use 885 00:53:32,360 --> 00:53:35,400 to make a photo of a black hole. 886 00:53:37,720 --> 00:53:39,520 It's really exciting. 887 00:53:39,520 --> 00:53:43,760 We just got the data and that's, you know, what we've been waiting for 888 00:53:43,760 --> 00:53:47,280 for many years, so it's a pretty exciting time for us. 889 00:53:49,440 --> 00:53:52,280 This is the moment when we finally get to see 890 00:53:52,280 --> 00:53:55,400 what a black hole might look like. 891 00:53:55,400 --> 00:53:57,920 Each member of the team loads the data 892 00:53:57,920 --> 00:54:00,240 and starts running their algorithms. 893 00:54:00,240 --> 00:54:03,000 Are we going to...? Are we doing this? 894 00:54:04,160 --> 00:54:07,160 OK? OK, ready? Ready, set, go. 895 00:54:07,160 --> 00:54:08,880 Going, going, going! 896 00:54:20,160 --> 00:54:22,880 The algorithms are producing some tantalising images. 897 00:54:24,360 --> 00:54:26,080 This is very early stages. 898 00:54:26,080 --> 00:54:27,760 This is exploratory surgery. 899 00:54:27,760 --> 00:54:29,440 Patient is on the table. 900 00:54:29,440 --> 00:54:31,800 Open the patient up, we're looking inside, 901 00:54:31,800 --> 00:54:33,480 we're trying to find out what we see. 902 00:54:36,240 --> 00:54:40,440 Each member of the team needs to zero in on one consistent image. 903 00:54:44,640 --> 00:54:46,280 That is interesting. 904 00:54:47,840 --> 00:54:49,960 Whoa. Oh! 905 00:54:49,960 --> 00:54:52,240 I'm getting something pretty similar - a little bit. 906 00:54:54,160 --> 00:54:57,160 And, with the data for the black hole M87, 907 00:54:57,160 --> 00:54:59,960 one image soon becomes clear. 908 00:55:03,240 --> 00:55:06,720 I see a circular feature. 909 00:55:11,480 --> 00:55:15,640 An image the likes of which astronomers have never seen before. 910 00:55:19,320 --> 00:55:22,720 What I'm seeing on the screen here is pretty startling. 911 00:55:22,720 --> 00:55:26,520 This is a case where the signal is so clear 912 00:55:26,520 --> 00:55:29,200 that it kind of hits you on the head with a hammer. 913 00:55:29,200 --> 00:55:30,600 If this holds up... 914 00:55:32,000 --> 00:55:34,320 ..it's going to be the discovery of my lifetime, 915 00:55:34,320 --> 00:55:37,680 and I think of many other people's lifetime, and... 916 00:55:39,080 --> 00:55:42,280 ..it's really sobering to see 917 00:55:42,280 --> 00:55:44,960 what a black hole looks like for the first time. 918 00:55:46,880 --> 00:55:50,840 The image shows photons of light being bent into a ring 919 00:55:50,840 --> 00:55:52,680 by the power of gravity. 920 00:55:54,120 --> 00:55:58,400 In the centre, a black hole with a mass of six billion suns 921 00:55:58,400 --> 00:56:01,600 is swallowing the light that strays too close. 922 00:56:01,600 --> 00:56:03,800 It is profound evidence 923 00:56:03,800 --> 00:56:06,520 that confirms the existence of black holes 924 00:56:06,520 --> 00:56:10,040 first predicted by Einstein's theory of gravity. 925 00:56:11,440 --> 00:56:14,680 This shows us that space time is distorted 926 00:56:14,680 --> 00:56:19,520 in the way that Einstein felt it would be at the black hole boundary, 927 00:56:19,520 --> 00:56:22,600 at the most extreme environment in the universe. 928 00:56:22,600 --> 00:56:27,240 These photons are struggling to get away from this black hole... 929 00:56:28,640 --> 00:56:32,440 ..and the black hole is tethering them with its immense gravity. 930 00:56:33,960 --> 00:56:37,800 And, every once in a while, some of them can just get away 931 00:56:37,800 --> 00:56:39,600 from the black hole and come to us. 932 00:56:39,600 --> 00:56:43,360 So we're seeing the very definition of this surface... 933 00:56:44,760 --> 00:56:46,800 ..where light is lost forever. 934 00:56:51,920 --> 00:56:57,760 In 2019, the Event Horizon Telescope team verified their data 935 00:56:57,760 --> 00:57:00,560 and released their results to the world. 936 00:57:11,400 --> 00:57:14,280 This is a ground-breaking scientific result. 937 00:57:17,720 --> 00:57:21,280 But, with plans for more telescopes and even better data, 938 00:57:21,280 --> 00:57:24,920 a picture of Sagittarius A-star could soon be next. 939 00:57:26,120 --> 00:57:29,640 When Galileo first proved that you can take pictures of the sky 940 00:57:29,640 --> 00:57:32,560 with telescopes, that didn't end astronomy - 941 00:57:32,560 --> 00:57:34,160 it started it. 942 00:57:36,080 --> 00:57:39,400 And in the same way, the most important scientific legacy 943 00:57:39,400 --> 00:57:41,600 of the Event Horizon Telescope is going to be 944 00:57:41,600 --> 00:57:44,840 the fact that it creates an entirely new field of science. 945 00:57:47,160 --> 00:57:49,840 If I know astronomers, when this thing is done, 946 00:57:49,840 --> 00:57:52,560 they'll go, "Ooh, what else can we do with this?" 947 00:57:52,560 --> 00:57:57,160 I can certainly envision that 10, 30, 50 years from now, 948 00:57:57,160 --> 00:57:59,480 our description of black holes are going to be 949 00:57:59,480 --> 00:58:01,560 completely, radically different. 950 00:58:02,880 --> 00:58:05,680 For Shep and the Event Horizon Telescope team, 951 00:58:05,680 --> 00:58:08,720 they hope this is just the beginning. 952 00:58:08,720 --> 00:58:10,600 We're not done. 953 00:58:10,600 --> 00:58:15,160 We don't actually like things to be tied up with a bow and finished. 954 00:58:16,520 --> 00:58:19,880 This shows us how black holes eat and how they feed 955 00:58:19,880 --> 00:58:22,280 in the way that has been impossible up to now. 956 00:58:23,520 --> 00:58:28,840 This, most of all, signals a whole new direction in astronomy - 957 00:58:28,840 --> 00:58:31,280 and that's rare. 958 00:58:31,280 --> 00:58:33,640 That is... It's really extraordinary.