WEBVTT 1 00:00:00.000 --> 00:00:02.440 This microphone must be working. Do you think it's working? 2 00:00:03.160 --> 00:00:04.300 What a surprise. 3 00:00:05.640 --> 00:00:08.920 We'll just wait while various persons come in. 4 00:00:09.920 --> 00:00:11.620 Ladies and gentlemen, the aliens. 5 00:00:13.120 --> 00:00:14.720 About 10% aliens. 6 00:00:15.420 --> 00:00:20.260 I recognise there's a tiny aerial you've got from behind the ear, 7 00:00:21.320 --> 00:00:23.860 which we who come from planet Zog recognise. 8 00:00:23.860 --> 00:00:24.060 I recognise. 9 00:00:28.520 --> 00:00:31.980 Paul Davis actually managed to be the only person... 10 00:00:32.680 --> 00:00:37.700 Sorry, the only plane to escape Sydney when it was totally fogged in. 11 00:00:38.700 --> 00:00:43.340 So he has certain supernatural powers which he exercised. 12 00:00:44.020 --> 00:00:45.200 It was the only plane, wasn't it? 13 00:00:45.500 --> 00:00:48.700 Well, the first plane, and it didn't look too promising for the rest. 14 00:00:49.480 --> 00:00:52.160 Sydney's badly fogged in today, and so is Canberra, 15 00:00:52.180 --> 00:00:53.620 and it looked like nothing. 16 00:00:53.860 --> 00:00:56.940 I was going to leave this morning, and then suddenly they announced a flight would leave, 17 00:00:57.080 --> 00:00:58.560 and it turned out to be the ones who had to leave. 18 00:00:58.640 --> 00:01:01.420 So I scrambled on board and said thanks. 19 00:01:02.700 --> 00:01:05.140 I've always blamed the federal government for fog. 20 00:01:06.900 --> 00:01:09.420 You can see it emanating from Canberra 21 00:01:09.420 --> 00:01:14.120 and spreading like some sort of stealthy object across the nation. 22 00:01:16.280 --> 00:01:19.440 Intellectual fog, that is, not just meteorological. 23 00:01:20.620 --> 00:01:22.760 This is my first festival of ideas, 24 00:01:22.760 --> 00:01:25.100 and gosh, I'm impressed. 25 00:01:25.920 --> 00:01:29.100 They thought they were really impressed in Melbourne during the Deakin lectures 26 00:01:29.100 --> 00:01:31.620 when on a Sunday when it was just as sunny, 27 00:01:31.760 --> 00:01:34.920 they had a completely full house all day long 28 00:01:34.920 --> 00:01:37.240 for lecture after lecture after lecture to do with science. 29 00:01:39.260 --> 00:01:41.940 So, well, it's now just after 1.15. 30 00:01:42.620 --> 00:01:43.600 Let us begin. 31 00:01:43.920 --> 00:01:49.520 This is Paul Davis, who, of course, has a couple of chairs at a couple of universities. 32 00:01:50.240 --> 00:01:52.480 One in London, Imperial College, is it not? 33 00:01:52.760 --> 00:01:56.540 And he's also a person of this town 34 00:01:56.540 --> 00:02:00.700 and written several books, one of which is about aliens. 35 00:02:01.660 --> 00:02:02.240 Are we alone? 36 00:02:02.800 --> 00:02:03.700 Got it right? 37 00:02:03.900 --> 00:02:04.420 Got it right. 38 00:02:04.560 --> 00:02:05.060 Splendid. 39 00:02:05.420 --> 00:02:09.580 And we thought we'd talk about aliens and intelligence 40 00:02:10.860 --> 00:02:14.860 and hint at the origins of life, perhaps, 41 00:02:14.940 --> 00:02:17.560 which is the subject of his latest book, The Fifth Miracle. 42 00:02:18.100 --> 00:02:22.400 But I want to start in a fairly definite way, 43 00:02:22.760 --> 00:02:26.280 usually discussions about extraterrestrial intelligence 44 00:02:26.280 --> 00:02:28.660 are about iffy stuff. 45 00:02:29.180 --> 00:02:32.300 I want to tell you that through the fog today, 46 00:02:33.840 --> 00:02:35.040 a message came through. 47 00:02:35.960 --> 00:02:38.500 They have actually been in touch. 48 00:02:39.260 --> 00:02:41.640 Clearly and obviously, they are here. 49 00:02:41.760 --> 00:02:43.720 Not necessarily on Earth. 50 00:02:43.940 --> 00:02:45.760 But the message has come through. 51 00:02:45.880 --> 00:02:48.600 There is intelligent life elsewhere. 52 00:02:48.920 --> 00:02:52.300 What do you think the reaction would be around the world? 53 00:02:52.760 --> 00:02:55.160 Well, first let me tell you what the protocol is. 54 00:02:55.760 --> 00:02:59.960 I'm assuming this message has been picked up by the Parkes radio telescope, 55 00:03:00.100 --> 00:03:04.100 which is always keeping out a metaphorical ear for incoming signals. 56 00:03:06.520 --> 00:03:08.400 Unlike what most people think, 57 00:03:08.500 --> 00:03:11.200 there is no international conspiracy of silence. 58 00:03:11.300 --> 00:03:13.160 The CIA is not involved in this. 59 00:03:13.280 --> 00:03:16.380 These are scientists at the forefront of this research program. 60 00:03:17.180 --> 00:03:20.280 And the first thing they do is open the champagne. 61 00:03:20.760 --> 00:03:21.320 Okay. 62 00:03:22.760 --> 00:03:26.800 The next thing they do is get the signal checked out by other facilities. 63 00:03:27.800 --> 00:03:32.040 And then they inform the International Astronomical Union, 64 00:03:32.600 --> 00:03:34.460 and I think the United Nations. 65 00:03:34.820 --> 00:03:39.480 And it's generally agreed, there's a protocol that's been drawn up over the years, 66 00:03:39.620 --> 00:03:43.920 that no reply should be sent without due deliberation being given. 67 00:03:45.020 --> 00:03:48.600 But beyond that, nobody has really thought it through. 68 00:03:48.820 --> 00:03:52.740 In fact, I've heard one or two people at the sharp end of this research program, 69 00:03:52.740 --> 00:03:57.680 say, well, if I picked up a signal now, I wouldn't actually know who to phone. 70 00:03:58.620 --> 00:04:05.440 So the idea that world governments move in and there's a conspiracy of silence is total nonsense. 71 00:04:05.700 --> 00:04:07.760 Now, the question is, what happens next? 72 00:04:08.020 --> 00:04:13.020 The media move in, they get hold of the story, and it's banner headlines around the world. 73 00:04:13.080 --> 00:04:13.760 Of course it is. 74 00:04:14.920 --> 00:04:19.300 Now, I like to compare this with Copernicus. 75 00:04:19.620 --> 00:04:22.720 Copernicus discovers that the Earth is going to be a place of peace, 76 00:04:22.740 --> 00:04:23.600 the sun is going to be shining, the sun is going to be shining. 77 00:04:23.600 --> 00:04:24.420 We've had it all wrong. 78 00:04:24.460 --> 00:04:26.560 Our whole perspective on the universe is transformed. 79 00:04:26.840 --> 00:04:29.360 Imagine the headlines when that was announced. 80 00:04:29.620 --> 00:04:34.480 Well, of course, it was before newspapers, so I don't know how that news was disseminated. 81 00:04:34.560 --> 00:04:35.860 But put ourselves in that position. 82 00:04:36.160 --> 00:04:41.060 You can imagine that for about a week, you'd hear of nothing else but this momentous discovery. 83 00:04:41.580 --> 00:04:47.980 Then I think after a week or so, people will go back to the cricket or politics 84 00:04:47.980 --> 00:04:50.340 or whatever it is that they usually worry about. 85 00:04:50.540 --> 00:04:52.500 We'd arrange some games with the aliens, you mean. 86 00:04:52.500 --> 00:04:58.300 I think this would be a story that would dominate everything 87 00:04:58.300 --> 00:05:02.780 and then it would be relegated to the back page 88 00:05:02.780 --> 00:05:06.320 and basically, unless there was some follow-up 89 00:05:06.320 --> 00:05:08.960 very little would be noticed 90 00:05:08.960 --> 00:05:11.640 looking back in history for a couple of hundred years 91 00:05:12.520 --> 00:05:14.380 you think, well, did that make any difference? 92 00:05:14.640 --> 00:05:17.240 and the answer is, in the end, yes, it would make an enormous difference 93 00:05:17.240 --> 00:05:20.460 to the way we view ourselves and our place in the universe 94 00:05:20.460 --> 00:05:23.960 because searching for aliens is really searching for ourselves 95 00:05:23.960 --> 00:05:26.280 who are we? where do we fit in? 96 00:05:27.320 --> 00:05:29.900 how do we relate to the great cosmic scheme of things? 97 00:05:30.160 --> 00:05:32.640 and if you think back to the Copernicus example I gave 98 00:05:32.640 --> 00:05:35.720 well, I'm sure, one month after Copernicus 99 00:05:35.720 --> 00:05:38.180 people were just getting on with their daily lives 100 00:05:38.180 --> 00:05:39.700 much the same as before 101 00:05:39.700 --> 00:05:41.040 what does it matter to me? 102 00:05:41.280 --> 00:05:44.740 and I'm sure that most of the people in Adelaide and elsewhere would think 103 00:05:44.740 --> 00:05:47.720 what does it matter to me that there are aliens out there? 104 00:05:47.860 --> 00:05:50.200 but over a period of centuries 105 00:05:50.460 --> 00:05:52.660 it does seep into your consciousness 106 00:05:52.660 --> 00:05:55.300 the fact that we know that the Earth is just a planet 107 00:05:55.300 --> 00:05:57.140 going around just a star 108 00:05:57.140 --> 00:05:59.020 in a fairly typical galaxy 109 00:05:59.780 --> 00:06:02.180 and if we go ahead to Darwin 110 00:06:02.180 --> 00:06:04.880 the fact that we have discovered that we have emerged 111 00:06:04.880 --> 00:06:06.860 as part of a natural process of evolution 112 00:06:06.860 --> 00:06:09.160 from the animal kingdom 113 00:06:10.120 --> 00:06:12.080 all of these things help shape 114 00:06:12.080 --> 00:06:13.940 who we think we are and where we fit in 115 00:06:13.940 --> 00:06:15.840 so they do colour our world view 116 00:06:15.840 --> 00:06:18.100 but not in a headline-screaming manner 117 00:06:18.100 --> 00:06:19.520 how do you know, by the way, Paul 118 00:06:19.520 --> 00:06:20.080 did you ask? 119 00:06:20.460 --> 00:06:21.380 when you're preparing your book 120 00:06:21.380 --> 00:06:22.600 how do you know that 121 00:06:22.600 --> 00:06:24.720 the President of the United States 122 00:06:24.720 --> 00:06:27.900 doesn't have a special message and a red button or something 123 00:06:28.600 --> 00:06:31.120 and that similar leaders around the world 124 00:06:31.740 --> 00:06:33.640 presumably they'd keep that secret from you 125 00:06:33.640 --> 00:06:35.800 well, of course, if they're going to keep it secret 126 00:06:35.800 --> 00:06:37.080 then I'm not going to know about it 127 00:06:37.700 --> 00:06:40.320 no, the main problem with politicians is not so much 128 00:06:40.320 --> 00:06:41.500 that they want to get in on the act 129 00:06:41.500 --> 00:06:46.440 it's that they don't regard this entire scientific research program 130 00:06:46.440 --> 00:06:47.360 as remotely credible 131 00:06:47.360 --> 00:06:49.920 and they're too busy axing the funds for it 132 00:06:49.920 --> 00:06:51.560 in fact, it's fairly true to say 133 00:06:51.560 --> 00:06:53.900 there's almost no government money anywhere in the world 134 00:06:54.460 --> 00:06:56.220 for the search for extraterrestrial intelligence 135 00:06:56.220 --> 00:06:58.060 it's almost all privately funded 136 00:06:59.160 --> 00:07:03.340 and a great deal has been put in by Mr Hewlett and Mr Packard 137 00:07:04.740 --> 00:07:06.100 I'm not sure about Bill Gates 138 00:07:06.100 --> 00:07:09.000 but, you know, it's those sorts of people who are putting money up 139 00:07:09.000 --> 00:07:12.260 and we haven't said anything about the technology 140 00:07:12.260 --> 00:07:14.280 but most people here will probably know 141 00:07:15.000 --> 00:07:19.760 that the most promising way of searching for extraterrestrial intelligence 142 00:07:19.760 --> 00:07:19.900 is to use the technology that we have available to us 143 00:07:19.900 --> 00:07:30.560 but the way we've taken the technology 144 00:07:30.560 --> 00:07:30.600 as a way of approaching the fourth world 145 00:07:30.600 --> 00:07:33.280 as a way of approaching the fourth world 146 00:07:33.280 --> 00:07:34.100 as a way of approaching the fourth world 147 00:07:34.100 --> 00:07:37.220 as a way of approaching the fourth world 148 00:07:37.220 --> 00:07:37.280 as a way of approaching the fourth world 149 00:07:37.280 --> 00:07:38.340 as a way of approaching the fourth world 150 00:07:38.340 --> 00:07:38.460 as a way of approaching the fourth world 151 00:07:38.460 --> 00:07:38.500 as a way of approaching the fourth world 152 00:07:38.500 --> 00:07:39.620 as a way of approaching the fourth world 153 00:07:39.620 --> 00:07:40.960 as a way of approaching the fourth world 154 00:07:41.460 --> 00:07:43.080 as a way of approaching the fourth world 155 00:07:43.080 --> 00:07:45.780 as a way of approaching the fourth world 156 00:07:45.780 --> 00:07:49.760 as a way of approaching the fourth world 157 00:07:49.760 --> 00:07:54.540 it costs only $40,000, and as the telescope goes about its normal business, 158 00:07:56.280 --> 00:07:58.740 it's listening out for the aliens at the same time. 159 00:07:58.960 --> 00:08:02.960 You could find signals that have a pattern that seem to imply that that's an alien. 160 00:08:03.220 --> 00:08:07.080 Well, this is a deep issue. How do we know that we've picked up a signal? 161 00:08:07.460 --> 00:08:11.740 Now, in the early days of SETI, and it goes back 40 years now, this technique, 162 00:08:12.300 --> 00:08:14.540 they were picking up signals all the time, of course, 163 00:08:14.540 --> 00:08:20.340 and it was taxi drivers and satellites and local radio stations and whatnot. 164 00:08:21.440 --> 00:08:24.100 And, of course, these are easily recognisable as intelligent. 165 00:08:25.080 --> 00:08:31.760 There was a famous false alarm in 1967 when, in Cambridge in the UK, 166 00:08:33.380 --> 00:08:37.180 Anthony Hewish's student Jocelyn Bell, as she was at the time, 167 00:08:37.240 --> 00:08:43.580 noticed a strange pulsation coming from the sky and didn't know what it was. 168 00:08:43.920 --> 00:08:44.520 That was it. 169 00:08:44.540 --> 00:08:48.220 drew Hewish's attention to it, and it was dubbed LGM for Little Green Men, 170 00:08:48.680 --> 00:08:52.240 because this was a very regular blip, blip, blip, blip, 171 00:08:52.260 --> 00:08:56.940 with extraordinary precision, and hinting at artificiality. 172 00:08:57.100 --> 00:09:00.080 And for about six months they followed this, and then they found another one, 173 00:09:00.140 --> 00:09:04.500 and they thought, well, the chances of detecting two of these things are so remote, 174 00:09:04.540 --> 00:09:05.920 it's got to be a natural phenomenon. 175 00:09:06.040 --> 00:09:09.900 And it turned out to be what we would now call pulsars, rotating neutron stars. 176 00:09:09.900 --> 00:09:14.420 And so there are processes in nature which will give you regularity. 177 00:09:14.560 --> 00:09:16.220 What is the signature of intelligence? 178 00:09:16.780 --> 00:09:19.840 Clearly not periodicity, not regularity. 179 00:09:19.880 --> 00:09:22.880 What you need is some sort of information content. 180 00:09:23.260 --> 00:09:29.220 And if, for example, you had radio blips that were pumping out the prime numbers 181 00:09:29.220 --> 00:09:37.900 or some mathematical content, then you would be pretty sure to ascribe that to some sort of intelligence. 182 00:09:38.360 --> 00:09:39.880 In fact, it's quite... 183 00:09:39.880 --> 00:09:46.040 It's quite a deep issue when you think about the misunderstandings that occur in Australia 184 00:09:46.040 --> 00:09:50.600 between the Aboriginal and white communities. 185 00:09:52.780 --> 00:09:58.460 Think of how two completely different species that had evolved on different planets 186 00:09:58.460 --> 00:10:02.020 in totally different ways, think of what would they have to say to each other. 187 00:10:02.100 --> 00:10:05.360 My feeling is that the aliens, if they're there, 188 00:10:05.500 --> 00:10:09.340 would understand nothing of our politics or our sport, 189 00:10:09.880 --> 00:10:13.280 or probably our religion, maybe not even our science. 190 00:10:13.420 --> 00:10:15.960 But the one thing we would have in common, I think, is mathematics. 191 00:10:16.280 --> 00:10:19.060 Because we live in a mathematical universe. 192 00:10:19.120 --> 00:10:20.640 The laws of nature are mathematical. 193 00:10:21.120 --> 00:10:23.180 And if they're going to be communicating with us, 194 00:10:23.220 --> 00:10:28.080 they would have to have some understanding of those mathematical principles underlying the laws of nature. 195 00:10:28.220 --> 00:10:29.420 So that would be the starting point. 196 00:10:29.600 --> 00:10:35.460 So we would expect any sort of signature of intelligence to have some mathematical content. 197 00:10:35.740 --> 00:10:38.960 So these people who are doing this with the radio telescope, 198 00:10:39.880 --> 00:10:43.740 they have all sorts of fancy software that will analyse the signals they pick up 199 00:10:43.740 --> 00:10:48.820 and look for some sort of mathematical content. 200 00:10:49.000 --> 00:10:50.400 If I could just tell a bit of a yarn about that. 201 00:10:50.500 --> 00:10:52.680 I don't know whether the Jocelyn Bell story... 202 00:10:52.680 --> 00:10:58.900 There was a play on television, on the ABC, produced by the BBC, 203 00:10:59.600 --> 00:11:01.960 a few years ago, showing exactly this. 204 00:11:01.980 --> 00:11:09.160 And there was Jocelyn Bell in her sort of anorak, right early in the morning, 205 00:11:09.900 --> 00:11:14.820 and you saw, they weren't dishes, but they displayed an array... 206 00:11:14.820 --> 00:11:15.720 Chicken wire, I think it was. 207 00:11:15.720 --> 00:11:16.480 Chicken wire, that's right. 208 00:11:16.620 --> 00:11:20.220 It was a bit like a vineyard with all these fences going up. 209 00:11:20.360 --> 00:11:24.940 And there she was, and suddenly she realised that the signal was coming through. 210 00:11:26.220 --> 00:11:29.760 And she looked very carefully and checked and double-checked 211 00:11:29.760 --> 00:11:31.680 and realised this was a very weird thing 212 00:11:31.680 --> 00:11:36.580 and went along to see Hewish and Ryle and told them of the discovery. 213 00:11:36.580 --> 00:11:38.840 And they were quite puzzled and wondered what to do. 214 00:11:38.880 --> 00:11:39.780 And, of course, they had the... 215 00:11:39.880 --> 00:11:42.860 the closure for three weeks where they didn't really tell anybody 216 00:11:42.860 --> 00:11:44.640 because they thought people might panic. 217 00:11:45.120 --> 00:11:49.540 And then, in the film, you had a press conference 218 00:11:49.540 --> 00:11:53.380 where these great scientists, who eventually got the Nobel Prize, 219 00:11:53.560 --> 00:11:54.220 she didn't, 220 00:11:55.600 --> 00:11:58.620 they're standing at the front and the press is milling around the front, 221 00:11:58.740 --> 00:12:00.560 around looking at them, 222 00:12:00.620 --> 00:12:05.540 and behind is little Jocelyn Bell, still in her little anorak, 223 00:12:05.640 --> 00:12:09.660 and a journalist comes up to her and says, 224 00:12:09.880 --> 00:12:11.380 are you Jocelyn Bell? 225 00:12:11.500 --> 00:12:13.480 And she says, oh, yes, thinking this is attention. 226 00:12:14.040 --> 00:12:15.520 What are your vital statistics? 227 00:12:17.180 --> 00:12:21.000 And when I interviewed her, I said, did he really ask that? 228 00:12:21.080 --> 00:12:22.860 And she said, there was no press conference. 229 00:12:24.240 --> 00:12:26.600 Which shows you how they embroider various things. 230 00:12:26.720 --> 00:12:28.320 But when you ask her whether she was resentful 231 00:12:28.320 --> 00:12:30.580 about the fact that these two professors 232 00:12:30.580 --> 00:12:34.920 who actually got the Nobel Prize for physics for other work as well, 233 00:12:35.100 --> 00:12:37.140 whether she resents the fact that she didn't, 234 00:12:37.160 --> 00:12:39.720 she says, well, she's dined out so much on this, 235 00:12:39.880 --> 00:12:42.780 that she's actually had all the benefits 236 00:12:42.780 --> 00:12:44.740 without necessarily having all that money. 237 00:12:44.880 --> 00:12:48.520 Anyway, we've established what might happen 238 00:12:48.520 --> 00:12:51.520 and also possibly some of the nature of the signal, 239 00:12:51.560 --> 00:12:52.700 which we can come back to. 240 00:12:53.840 --> 00:12:57.300 The one thing that bothers me is, 241 00:12:57.420 --> 00:12:59.120 as we talk about the tyranny of distance, 242 00:12:59.220 --> 00:13:01.360 this really is a huge problem. 243 00:13:01.980 --> 00:13:06.320 We'll come to the tyranny of distance as how you said you can't reply. 244 00:13:07.280 --> 00:13:09.300 To be able to reply to anything, 245 00:13:09.880 --> 00:13:12.780 even in our close neighborhood is difficult 246 00:13:12.780 --> 00:13:16.760 because the image I like to remember in terms of distance 247 00:13:16.760 --> 00:13:20.520 is if you had the Sermon on the Mount 2,000 years ago 248 00:13:20.520 --> 00:13:24.980 transmitted by radio and traveling naturally at the speed of light, 249 00:13:25.160 --> 00:13:30.020 it would still be only out of the neighborhood in our galaxy. 250 00:13:31.140 --> 00:13:33.880 It won't have left remotely the galaxy, 251 00:13:34.200 --> 00:13:36.560 let alone traveled any greater distance. 252 00:13:36.900 --> 00:13:39.860 So when you think of the distances that have to travel, 253 00:13:39.880 --> 00:13:43.340 to get a signal across, it really is boggling. 254 00:13:43.640 --> 00:13:46.780 Yeah, I think this is the big downside of the whole SETI program. 255 00:13:47.280 --> 00:13:51.540 I like to describe SETI, that acronym I keep using, 256 00:13:51.800 --> 00:13:53.760 Search for Extraterrestrial Intelligence. 257 00:13:54.700 --> 00:13:58.820 I like to describe it as a glorious but almost certainly hopeless quest. 258 00:13:59.260 --> 00:14:02.200 Now, I think it's worth doing for all sorts of reasons we can go into, 259 00:14:02.780 --> 00:14:04.240 but why do I think it's hopeless? 260 00:14:04.400 --> 00:14:07.040 Well, first of all, we have no idea whether there's any life out there 261 00:14:07.040 --> 00:14:08.340 of any description whatever, 262 00:14:08.620 --> 00:14:09.860 let alone intelligence. 263 00:14:09.880 --> 00:14:10.180 We have no idea whether there's intelligent life, 264 00:14:10.260 --> 00:14:12.280 and even if there is intelligent life out there, 265 00:14:12.380 --> 00:14:14.840 we have no idea how widespread it is. 266 00:14:14.980 --> 00:14:17.820 Though my feeling is that this is an all or nothing thing. 267 00:14:17.920 --> 00:14:20.480 Either we are alone in the universe, 268 00:14:20.600 --> 00:14:22.500 or it's teeming with intelligent life. 269 00:14:22.580 --> 00:14:24.800 I don't think that it would be too much of a coincidence 270 00:14:24.800 --> 00:14:27.580 if the factors which determined the number 271 00:14:27.580 --> 00:14:29.860 or the emergence of intelligence in evolution 272 00:14:29.860 --> 00:14:33.940 were matched to the factors that determine the number of stars in the universe. 273 00:14:34.420 --> 00:14:36.760 They're unrelated, so it's going to be all or nothing. 274 00:14:36.900 --> 00:14:37.940 They're either everywhere or nowhere. 275 00:14:39.480 --> 00:14:41.740 Supposing we take the optimistic view that they're everywhere, 276 00:14:42.080 --> 00:14:46.740 now even the great proponents of SETI like Carl Sagan 277 00:14:46.740 --> 00:14:50.040 would put the chances of another communicating civilization 278 00:14:50.040 --> 00:14:53.560 being within a hundred light years of Earth as being rather slim. 279 00:14:53.740 --> 00:14:55.680 So let's take the most optimistic estimate and say, 280 00:14:55.800 --> 00:14:58.700 okay, ET is out there a hundred light years away. 281 00:14:58.980 --> 00:15:03.220 Now, would we expect if we happen to turn our telescope on the right star 282 00:15:03.220 --> 00:15:05.080 and tune into the right channel, 283 00:15:06.320 --> 00:15:07.920 would we expect that the Earth would be in the right place? 284 00:15:07.940 --> 00:15:09.360 Would we expect to pick up a message from them? 285 00:15:09.680 --> 00:15:11.300 And the answer is, well, surely not. 286 00:15:11.960 --> 00:15:16.720 And the reason is, imagine sitting on a funding committee on this distant planet, 287 00:15:17.180 --> 00:15:21.760 and people there are trying to make a case for setting up a radio beacon. 288 00:15:21.980 --> 00:15:24.320 Then maybe they guess that there's life on Earth 289 00:15:24.320 --> 00:15:26.660 and it may evolve intelligence at some stage. 290 00:15:27.080 --> 00:15:28.000 Maybe it hasn't yet. 291 00:15:30.100 --> 00:15:33.320 And they want to beam signals at us. 292 00:15:33.820 --> 00:15:37.240 And the funding committee says, well, how long is this going to go on for? 293 00:15:37.240 --> 00:15:40.560 And they say, well, all we know is that sometime in the next few million years 294 00:15:41.100 --> 00:15:43.120 intelligent life is likely to emerge on Earth. 295 00:15:43.360 --> 00:15:46.000 So can we beam messages for a few million years? 296 00:15:47.000 --> 00:15:48.760 And then a counter-proposal comes in. 297 00:15:48.800 --> 00:15:54.140 The counter-proposal says, well, could we just set up a listening device? 298 00:15:54.220 --> 00:15:56.900 Either we send a probe to the solar system, 299 00:15:57.020 --> 00:15:59.500 or we have a passive receiver, which is very cheap, 300 00:15:59.600 --> 00:16:03.260 much cheaper than blasting the ether with expensive radio waves. 301 00:16:03.980 --> 00:16:06.040 And we'll wait and see if we pick anything up. 302 00:16:06.080 --> 00:16:07.220 And if we pick up a radio signal, 303 00:16:07.240 --> 00:16:08.240 from the solar system, 304 00:16:08.440 --> 00:16:10.880 then we'll send them a message, because we know they're on the air. 305 00:16:11.240 --> 00:16:13.420 Now obviously you're going to fund the cheaper one. 306 00:16:13.560 --> 00:16:17.400 You're not going to just waste all that energy and money 307 00:16:18.120 --> 00:16:19.860 sending signals for millions and millions of years 308 00:16:19.860 --> 00:16:23.100 just to save the hundred years that it would take 309 00:16:23.580 --> 00:16:25.160 for the signals to go back and forth. 310 00:16:25.280 --> 00:16:27.740 So they're going to wait until they pick up our first radio signals 311 00:16:28.140 --> 00:16:29.580 before they send their message. 312 00:16:29.780 --> 00:16:31.400 And our first radio signals, as you mentioned, 313 00:16:31.520 --> 00:16:34.080 well, didn't have radio for the Sermon on the Mount. 314 00:16:34.340 --> 00:16:35.900 Radio goes back about a hundred years. 315 00:16:35.900 --> 00:16:40.340 So our signals have got about a hundred light years out into the galaxy. 316 00:16:40.580 --> 00:16:42.320 So if ET is at an optimistic distance, 317 00:16:42.740 --> 00:16:45.300 they'll about now be going to their funding body saying, 318 00:16:45.460 --> 00:16:48.560 it worked, we've been listening for the last ten million years, 319 00:16:48.640 --> 00:16:51.180 we finally picked up that signal, let's send them the hello message. 320 00:16:51.560 --> 00:16:53.060 So if you wait about another hundred years, 321 00:16:53.820 --> 00:16:56.200 then we might be lucky, we might get that message. 322 00:16:56.360 --> 00:17:00.240 So that's my feeling, that it's the right technology, 323 00:17:00.500 --> 00:17:01.760 or at least it's the obvious technology, 324 00:17:02.060 --> 00:17:05.820 but it's about a hundred years too soon to really expect to get. 325 00:17:06.620 --> 00:17:10.300 The other worry is, of course, this, and you would have thought of this, 326 00:17:10.440 --> 00:17:14.820 that given that the universe is 15 billion years old, more or less, 327 00:17:15.020 --> 00:17:18.600 and given that our part of it is four and a half billion, 328 00:17:18.820 --> 00:17:22.580 so we've been around for a third of the length of the universe, 329 00:17:22.820 --> 00:17:28.660 surely by now they have had enough time just to send some sort of message, 330 00:17:28.960 --> 00:17:31.960 they've had an extra five billion, seven billion years, 331 00:17:32.180 --> 00:17:35.800 to spray out something, which surely we would have picked up. 332 00:17:35.820 --> 00:17:38.120 Well, it's very important to look at these statistics, 333 00:17:38.200 --> 00:17:41.180 because a lot of people leap to all sorts of strange conclusions. 334 00:17:41.400 --> 00:17:43.880 The first one they leap to is, they say, 335 00:17:43.960 --> 00:17:47.640 well, there are all these billions and billions of stars, to use the jargon, 336 00:17:47.740 --> 00:17:50.500 so surely there must be life out there somewhere, 337 00:17:50.660 --> 00:17:51.980 because the universe is so vast. 338 00:17:52.220 --> 00:17:52.880 Not true. 339 00:17:53.440 --> 00:17:58.960 If you look at the factors that determine how life comes into being from non-life, 340 00:17:59.080 --> 00:18:04.600 if you just take molecules, take organic molecules of the sort that we're all made of, 341 00:18:04.600 --> 00:18:08.420 just shuffle them at random in some sort of primordial soup, 342 00:18:08.940 --> 00:18:11.740 you would shuffle for far longer than the age of the universe 343 00:18:11.740 --> 00:18:13.840 before you produce even a single protein. 344 00:18:14.040 --> 00:18:18.900 So if life forms just by a chemical freak, a chemical quirk like that, 345 00:18:19.560 --> 00:18:21.020 we're going to be alone in the universe. 346 00:18:21.040 --> 00:18:22.580 It doesn't matter how many billions of stars. 347 00:18:22.720 --> 00:18:27.200 The odds against making life by random shuffling are just stupendously greater. 348 00:18:27.480 --> 00:18:31.080 So the vastness of the universe is not a factor. 349 00:18:31.140 --> 00:18:34.200 The sort of numbers we're talking about here are much, much bigger or smaller. 350 00:18:35.200 --> 00:18:36.420 So that's the first thing. 351 00:18:36.500 --> 00:18:40.120 The second thing is if there is some sort of life principle built into the laws of nature, 352 00:18:40.220 --> 00:18:41.660 and we don't know of one, but if there is one, 353 00:18:41.780 --> 00:18:45.600 which means that life pops up wherever and whenever there are Earth-like conditions, 354 00:18:46.400 --> 00:18:49.380 then imagine that there's another planet somewhere else in our galaxy 355 00:18:49.380 --> 00:18:52.180 that was formed at exactly the same moment as the Earth. 356 00:18:52.360 --> 00:18:54.380 Itself an unusual circumstance. 357 00:18:55.280 --> 00:18:57.920 Imagine that life gets going at exactly the same time, 358 00:18:58.000 --> 00:18:59.660 and you've got these two planets. 359 00:18:59.680 --> 00:19:02.740 Off they go on their independent evolutionary pathways. 360 00:19:03.760 --> 00:19:08.480 Now, what are the chances that these other planets will parallel evolution on Earth 361 00:19:08.480 --> 00:19:12.060 to the extent that after about four billion years, 362 00:19:12.280 --> 00:19:17.080 you end up with technological civilization emerging at the same time, 363 00:19:17.080 --> 00:19:18.800 within a few hundred years of each other, you see? 364 00:19:19.000 --> 00:19:20.280 Obviously, it's infinitesimal. 365 00:19:20.400 --> 00:19:25.540 If the asteroid that wiped out the dinosaurs had arrived ten minutes later 366 00:19:25.540 --> 00:19:27.420 and failed to hit the Earth, 367 00:19:28.100 --> 00:19:32.440 then almost certainly there'd be no mammals and we wouldn't have technology on Earth, I don't think. 368 00:19:33.200 --> 00:19:35.140 So, when you look at the evolutionary history, 369 00:19:35.340 --> 00:19:39.480 there are so many contingent events that you're never going to parallel that on another planet. 370 00:19:39.760 --> 00:19:42.600 So, what this means is after four billion years of evolution, 371 00:19:42.900 --> 00:19:45.200 if that's the average that it takes, and we don't know, 372 00:19:45.640 --> 00:19:46.940 but suppose that's the average, 373 00:19:47.620 --> 00:19:52.260 you're going to have variations by millions of years in the evolutionary development. 374 00:19:52.640 --> 00:19:55.140 So, what that tells us is that if ET is out there, 375 00:19:55.280 --> 00:19:58.760 they're going to be either way, way ahead of us or way, way behind us. 376 00:19:58.800 --> 00:20:00.520 Well, if they're behind us, we're not going to know they're there. 377 00:20:00.740 --> 00:20:02.720 So, we assume that if we're going to have evolution, 378 00:20:02.740 --> 00:20:06.000 that the Earthlings are the new kids on the block, 379 00:20:07.560 --> 00:20:11.280 and if there are a large number of communicating civilizations, 380 00:20:11.680 --> 00:20:14.760 they'll have been up and running for a long, long time. 381 00:20:14.900 --> 00:20:17.660 And as you pointed out, the Earth is a third as old as the universe. 382 00:20:17.860 --> 00:20:22.380 There could have been civilizations around billions of years before the Earth even formed. 383 00:20:22.680 --> 00:20:29.120 Now, it's impossible for us to envisage the nature of a technological civilization 384 00:20:29.120 --> 00:20:32.620 that is millions of years old, let alone billions of years old. 385 00:20:32.740 --> 00:20:36.760 It could totally transform the structure of the galaxy. 386 00:20:37.080 --> 00:20:38.060 We have no idea. 387 00:20:38.260 --> 00:20:41.800 But let's assume, of course, the other thing we don't know is how long they will last. 388 00:20:42.000 --> 00:20:44.540 You see, in the early days of this whole SETI business, 389 00:20:44.780 --> 00:20:47.540 everyone that was in the Cold War, everyone assumed, 390 00:20:47.620 --> 00:20:51.240 well, if we're typical, we're obviously going to blow ourselves up by the year 2000. 391 00:20:51.920 --> 00:20:55.620 So, the average lifetime of a communicating civilization is a few decades. 392 00:20:55.940 --> 00:21:00.080 And so, they'll be popping up all over the galaxy and promptly blowing themselves up. 393 00:21:00.180 --> 00:21:01.420 And so, there's no one out there anyway. 394 00:21:02.800 --> 00:21:04.740 But now people are a bit more optimistic, 395 00:21:04.820 --> 00:21:08.960 and they can envisage civilizations lasting for enormous durations. 396 00:21:09.320 --> 00:21:13.600 But if they do that, they'll establish a network of communication and information exchange. 397 00:21:14.520 --> 00:21:17.420 They're not going to be that fussed about the new kids on the block. 398 00:21:17.800 --> 00:21:20.320 They've been around millions and millions of years. 399 00:21:21.240 --> 00:21:22.960 We could certainly wait a little bit longer. 400 00:21:23.160 --> 00:21:27.420 They're not going to be spending too much effort on bringing us into the galactic club. 401 00:21:28.540 --> 00:21:30.920