WEBVTT 1 00:00:00.000 --> 00:00:05.840 Good morning. Welcome, everybody, to the first session of today in the Elder Hall as part of the Adelaide Festival of Ideas. 2 00:00:06.700 --> 00:00:12.240 Delighted to welcome you all along this morning. I'm delighted to welcome our speaker this morning, 3 00:00:12.340 --> 00:00:17.640 who I've actually known, I've just realized, for a quarter of a century, because it makes us both feel a little old. 4 00:00:18.100 --> 00:00:21.740 I was fortunate to be a PhD student at the University of Canterbury in New Zealand, 5 00:00:21.860 --> 00:00:28.660 and even though John Campbell and I were in very different areas, he very much took me underneath his wing and helped me along. 6 00:00:28.660 --> 00:00:33.880 John was a solid-state physicist, but that was only one of the evils which he indulged in. 7 00:00:33.920 --> 00:00:36.000 He's done lots and lots of different things at different times. 8 00:00:37.480 --> 00:00:45.420 I want to mention that he's written a book, which is available out in the bookshop there, about Rutherford, Rutherford's scientist supreme. 9 00:00:46.520 --> 00:00:50.140 John actually came to visit me when I was working here at the University of Adelaide, 10 00:00:50.180 --> 00:00:54.920 specifically to interview Sir Mark Oliphant, one-time Governor-General of South Australia, 11 00:00:55.080 --> 00:00:58.540 who I believe was the last surviving student of Lord Rutherford. 12 00:00:58.660 --> 00:01:02.360 So John has had an association with Adelaide in various ways for many years. 13 00:01:02.960 --> 00:01:08.820 I don't want to take any more of his time just to mention that another collaboration we had was playing in the same soccer team in New Zealand, 14 00:01:08.960 --> 00:01:11.560 which John mentions in his little biopic. 15 00:01:11.980 --> 00:01:18.600 It's called the Islam Hardys, and you might think that might have been a professional team sponsored by a big Australian corporation or something like that. 16 00:01:18.760 --> 00:01:23.140 Not at all. The Islam Hardy, in fact, is a local breed of potato. 17 00:01:24.660 --> 00:01:25.980 Over to you, John. Thank you. 18 00:01:32.800 --> 00:01:40.100 We have a problem with the public perception of science, and we see it almost every day. 19 00:01:46.520 --> 00:01:50.940 And so that's why you're here on a Saturday morning without paying to hear me. 20 00:01:53.800 --> 00:01:56.060 And of course the idiot box seldom helps. 21 00:01:58.000 --> 00:01:58.640 Here's a good example. 22 00:01:58.660 --> 00:01:59.940 You see a kid clicking around the channels. 23 00:02:00.280 --> 00:02:08.820 There's a physics discovery, some event that's going to go down in history, a tourist thing to Ethiopia. 24 00:02:10.780 --> 00:02:12.460 And he turns the door off. 25 00:02:12.560 --> 00:02:14.180 No, there's nothing on. He's not watching. 26 00:02:17.300 --> 00:02:24.680 This diagram came from 1983 when the Americans started getting worried about science teaching. 27 00:02:24.860 --> 00:02:26.380 In this case, it was physics teaching. 28 00:02:26.380 --> 00:02:41.780 And it sort of typified the aging teaching staff that perhaps had run out of steam and some of the dumb stuff that was going on that was being taught just by formula. 29 00:02:42.700 --> 00:02:55.920 I had a mate, a biology teacher, who taught a class of 15-year-olds, sorry, 14-year-olds, their bit of physics science through the science of motorbikes. 30 00:02:55.920 --> 00:02:57.180 It was a lower decile class. 31 00:02:58.040 --> 00:03:00.780 And they all got quite excited about science. 32 00:03:00.860 --> 00:03:02.800 It actually had something to do with their life. 33 00:03:02.980 --> 00:03:04.900 And so next year they all enrolled for physics. 34 00:03:05.420 --> 00:03:09.260 And to their horror, found out that real physics is equations written on a blackboard. 35 00:03:09.880 --> 00:03:11.800 It had nothing to do with motorbikes at all. 36 00:03:12.800 --> 00:03:14.600 And we get feedback from the students. 37 00:03:16.960 --> 00:03:19.800 Nowadays, enormous amounts of time wasted in doing this. 38 00:03:20.060 --> 00:03:22.600 But in the old days, they always gave us the message. 39 00:03:24.000 --> 00:03:25.440 And worse things happen at sea. 40 00:03:25.920 --> 00:03:27.420 And there we are at sea. 41 00:03:33.100 --> 00:03:36.820 There was a statement made two decades ago in Britain. 42 00:03:36.860 --> 00:03:38.620 They were getting worried about science teaching. 43 00:03:39.400 --> 00:03:51.800 If present trends continue, there's a real fear that physics will eventually be just an obtuse subject concerned with nuclear particles. 44 00:03:52.300 --> 00:03:54.240 Elementary particles rather than nuclear. 45 00:03:54.240 --> 00:03:56.860 And the rest will be absorbed into engineering. 46 00:03:57.160 --> 00:03:58.900 And that's happened to many things. 47 00:03:59.000 --> 00:04:03.220 Anything that gets to be a bit useful gets shunted out and forms another field. 48 00:04:04.020 --> 00:04:06.240 And so we have to be a little careful about this. 49 00:04:10.480 --> 00:04:15.720 There's also the point of physics being regarded as a fairly hard subject. 50 00:04:15.760 --> 00:04:18.340 It's the principal one that requires mathematics. 51 00:04:19.400 --> 00:04:22.020 And so people have to be reasonably okay in mathematics. 52 00:04:22.020 --> 00:04:43.620 And there's a statement written by a tutor, a graduate student who was tutoring lower people down the class who paid for extra tuition in order to get through things. 53 00:04:48.380 --> 00:04:50.680 Are there any university lecturers here? 54 00:04:51.100 --> 00:04:52.000 No? 55 00:04:52.000 --> 00:04:52.560 Right. 56 00:04:52.740 --> 00:04:54.720 You could appreciate that one, couldn't you? 57 00:04:55.780 --> 00:05:04.780 What makes this of interest is that this was set in 1894 at Canterbury by Ernest Rutherford. 58 00:05:09.900 --> 00:05:12.640 So we do have these problems. 59 00:05:13.700 --> 00:05:18.400 And a lot of teaching, particularly at university, is done through the cork method. 60 00:05:20.760 --> 00:05:21.740 You know the one. 61 00:05:21.740 --> 00:05:28.100 We shove a funnel in one ear, pour in a few textbooks, and bang a cork in the far ear to stop it draining straight through. 62 00:05:29.800 --> 00:05:37.780 And yet, Emma Toller, France, had the pith, really, of what we should be doing. 63 00:05:38.640 --> 00:05:42.360 Do not satisfy your vanity by teaching a great many things. 64 00:05:43.460 --> 00:05:44.860 Awaken people's curiosity. 65 00:05:45.900 --> 00:05:48.020 It is enough to open minds. 66 00:05:49.120 --> 00:05:50.540 Do not overload them. 67 00:05:50.540 --> 00:05:52.260 Put there just a spark. 68 00:05:52.480 --> 00:05:55.620 And if there is some good and flammable stuff, it will catch fire. 69 00:05:56.100 --> 00:06:01.960 And that is the role of the teacher, to give that spark, to turn people on. 70 00:06:02.080 --> 00:06:06.980 We can all think back to our school days and the teachers of influence in whatever field it was. 71 00:06:07.520 --> 00:06:10.120 Probably had a major influence in us. 72 00:06:10.740 --> 00:06:13.180 I remember a chemistry teacher at my school. 73 00:06:13.820 --> 00:06:17.900 He would have a beaker of acid and demonstrate how dangerous it was. 74 00:06:18.080 --> 00:06:20.480 And he would have a beaker of alkali and demonstrate how dangerous it was. 75 00:06:20.480 --> 00:06:22.100 Then he would pour the two together and drink it. 76 00:06:23.360 --> 00:06:26.120 Not very strong, of course, because he did not want to die of salt poisoning. 77 00:06:28.400 --> 00:06:29.740 And the electricity teacher. 78 00:06:30.480 --> 00:06:33.420 I mean, we did do electricity in those days as a subject. 79 00:06:34.920 --> 00:06:37.340 Always flashes and bangs going on in his class. 80 00:06:37.560 --> 00:06:38.520 Some of them intentional. 81 00:06:44.120 --> 00:06:48.940 So what we need to do is to inspire students to want to learn. 82 00:06:51.760 --> 00:06:54.820 We need them then to teach them how to learn. 83 00:06:55.020 --> 00:06:59.160 And that is something we don't really do at university level. 84 00:06:59.800 --> 00:07:02.680 All we do is cream the ones off the top. 85 00:07:04.700 --> 00:07:09.560 And we need to train them in useful skills to help them through all this. 86 00:07:15.120 --> 00:07:20.280 Now I will give a little bit of history lesson here of what used to happen in New Zealand. 87 00:07:20.480 --> 00:07:21.620 Because I thought it was a reasonable system. 88 00:07:22.160 --> 00:07:23.700 And I will deal mainly with physics. 89 00:07:26.300 --> 00:07:33.060 But New Zealand required 10 new physics teachers a year just for attrition of people retiring. 90 00:07:34.740 --> 00:07:36.560 They were graduates in physics. 91 00:07:36.720 --> 00:07:40.080 And they went to a teacher's college for a one year diploma in teaching. 92 00:07:42.040 --> 00:07:44.480 To be converted into teachers. 93 00:07:45.760 --> 00:07:47.720 These people were carefully selected. 94 00:07:47.920 --> 00:07:49.100 All fees were paid. 95 00:07:49.200 --> 00:07:50.460 All those sorts of things in those days. 96 00:07:50.460 --> 00:07:53.020 And they were selected through interviews. 97 00:07:53.200 --> 00:07:55.500 And they had 40 points awarded. 98 00:07:56.500 --> 00:08:00.320 Five of those were for what degree people had. 99 00:08:00.400 --> 00:08:01.160 The academic side. 100 00:08:03.560 --> 00:08:06.760 Now up until 20 or 30 years ago. 101 00:08:07.760 --> 00:08:12.940 An academic career wasn't really the first choice of a lot of people. 102 00:08:14.020 --> 00:08:18.540 And a lot of our politicians were quite proud of having left school at age 12. 103 00:08:18.540 --> 00:08:20.540 They didn't need higher education. 104 00:08:22.600 --> 00:08:27.400 This is really summed up by Andrew Board in the 16th century. 105 00:08:27.600 --> 00:08:30.080 A master of art is not worth a fart. 106 00:08:31.060 --> 00:08:32.400 But these five points. 107 00:08:32.760 --> 00:08:35.340 If you had a physics degree or a maths degree. 108 00:08:35.700 --> 00:08:37.220 You would get five out of five. 109 00:08:38.360 --> 00:08:44.060 If it was in ancient Greek history and there wasn't too many positions in high schools required for that. 110 00:08:44.160 --> 00:08:45.320 Then it would be lower down. 111 00:08:45.580 --> 00:08:47.700 But the other 35 points. 112 00:08:47.700 --> 00:08:53.160 Were all for things that we want of our teacher. 113 00:08:53.260 --> 00:08:53.980 Of our children. 114 00:08:54.740 --> 00:08:57.020 We want someone with a reasonable personality. 115 00:08:57.400 --> 00:09:00.300 The ability to write clearly and speak clearly. 116 00:09:01.700 --> 00:09:02.720 Slightly outgoing. 117 00:09:03.660 --> 00:09:03.700 Knowledgeable. 118 00:09:04.260 --> 00:09:04.540 Happy. 119 00:09:05.060 --> 00:09:05.980 Mentally stable. 120 00:09:06.260 --> 00:09:07.420 All of these sorts of things. 121 00:09:08.160 --> 00:09:11.520 Played sports so they can take a school sports team. 122 00:09:12.800 --> 00:09:14.440 And of course a sense of humour. 123 00:09:14.620 --> 00:09:17.080 And boy these days do they need a sense of humour. 124 00:09:17.720 --> 00:09:19.840 Now I thought that system worked pretty well. 125 00:09:20.960 --> 00:09:22.560 And then a political masters. 126 00:09:22.800 --> 00:09:26.120 And one of their more idiotic moments. 127 00:09:28.040 --> 00:09:31.180 Funded universities in particular by bums on seats. 128 00:09:32.140 --> 00:09:35.220 So the college of education would take in anyone. 129 00:09:36.280 --> 00:09:38.760 Now previously those people were chosen. 130 00:09:38.940 --> 00:09:40.560 There were the jobs to go to. 131 00:09:40.720 --> 00:09:42.060 And they were sought after. 132 00:09:43.240 --> 00:09:45.740 Now with bums on seats they took in more people. 133 00:09:45.780 --> 00:09:47.480 A large number were from overseas. 134 00:09:47.700 --> 00:09:50.120 They had English as a second language. 135 00:09:50.340 --> 00:09:52.960 The vast majority of these. 136 00:09:53.100 --> 00:09:54.060 And certainly in physics. 137 00:09:54.500 --> 00:09:57.240 No headmaster would employ them. 138 00:09:57.880 --> 00:10:00.900 And these poor people were being charged enormous fees. 139 00:10:01.320 --> 00:10:05.500 To train for something where they wouldn't get a decent job. 140 00:10:06.860 --> 00:10:08.140 And what happened to them? 141 00:10:08.320 --> 00:10:09.900 Well actually I did find them. 142 00:10:10.500 --> 00:10:13.660 I did a tour of Northland schools last year. 143 00:10:13.820 --> 00:10:14.840 And there they were. 144 00:10:14.960 --> 00:10:16.920 The sole charge physics teacher. 145 00:10:16.920 --> 00:10:19.140 In a small town high school. 146 00:10:19.280 --> 00:10:24.500 That had no way of attracting any decent physics teacher. 147 00:10:25.960 --> 00:10:27.140 So that was a disaster. 148 00:10:27.340 --> 00:10:28.820 We're just about to do the second one. 149 00:10:29.580 --> 00:10:36.280 And that is this year the teachers colleges became under colleges of education and universities. 150 00:10:37.580 --> 00:10:41.020 That is going to leave those colleges like what happened here 20 years ago. 151 00:10:41.140 --> 00:10:42.180 Over staffed. 152 00:10:42.180 --> 00:10:43.540 Who are they going to get rid of? 153 00:10:43.680 --> 00:10:46.220 The ones without a large publication record. 154 00:10:46.220 --> 00:10:49.360 I.e. the good classroom practicing teacher. 155 00:10:49.520 --> 00:10:51.820 That is going to be training these students. 156 00:10:51.960 --> 00:10:54.820 On classroom side of things. 157 00:10:55.540 --> 00:10:57.740 So it's a bit of a shame. 158 00:10:59.540 --> 00:11:07.420 Society needs to ensure that good quality people go into teaching. 159 00:11:09.680 --> 00:11:12.300 Science is really based on this. 160 00:11:12.480 --> 00:11:15.340 The teachers are the salesman for any subject. 161 00:11:15.340 --> 00:11:16.680 If you've got enthusiasm. 162 00:11:18.100 --> 00:11:20.280 They're going to be doing it class after class. 163 00:11:20.420 --> 00:11:21.640 And year after year. 164 00:11:23.520 --> 00:11:29.920 Whereas you can put in one that could turn class after class off that subject. 165 00:11:31.780 --> 00:11:33.860 In the preface to Nicholas Nickleby. 166 00:11:34.540 --> 00:11:36.260 Charles Dickens wrote the following. 167 00:11:37.660 --> 00:11:42.700 We hear sometimes of an action for damages against an unqualified medical practitioner. 168 00:11:42.840 --> 00:11:44.800 Who has deformed a broken limb. 169 00:11:46.160 --> 00:11:47.580 In pretending to heal it. 170 00:11:48.880 --> 00:11:51.140 But what are the minds that have been deformed forever. 171 00:11:51.280 --> 00:11:53.980 By the incapable pitty foggers. 172 00:11:54.080 --> 00:11:55.700 Who have pretended to form them. 173 00:11:56.380 --> 00:11:59.000 Now clearly they had some people in teaching. 174 00:11:59.100 --> 00:12:00.080 Who perhaps shouldn't have been there. 175 00:12:00.160 --> 00:12:00.980 Way back then. 176 00:12:03.420 --> 00:12:03.900 Right. 177 00:12:05.360 --> 00:12:06.360 That's all a bit dry. 178 00:12:08.700 --> 00:12:09.640 Thirsty work this. 179 00:12:13.300 --> 00:12:14.600 Oh I've got a spare camera. 180 00:12:14.600 --> 00:12:16.000 Would anyone like a drink with me. 181 00:12:16.720 --> 00:12:17.080 Anyone. 182 00:12:18.060 --> 00:12:18.900 Might as well be generous. 183 00:12:19.780 --> 00:12:20.280 Tim will. 184 00:12:22.860 --> 00:12:23.540 I'll bring it down. 185 00:12:23.660 --> 00:12:24.080 I'll bring it down. 186 00:12:25.720 --> 00:12:26.080 . 187 00:12:29.960 --> 00:12:30.320 . 188 00:12:30.320 --> 00:12:31.480 . 189 00:12:31.480 --> 00:12:32.220 . 190 00:12:32.220 --> 00:12:34.720 . 191 00:12:39.260 --> 00:12:40.660 . 192 00:12:40.660 --> 00:12:43.400 . 193 00:12:43.400 --> 00:12:43.500 . 194 00:12:43.500 --> 00:12:44.420 . 195 00:12:44.420 --> 00:12:44.660 . 196 00:12:44.660 --> 00:12:46.420 . 197 00:12:46.420 --> 00:12:46.440 . 198 00:12:48.340 --> 00:12:49.740 . 199 00:12:49.740 --> 00:12:49.780 . 200 00:12:49.780 --> 00:12:49.960 . 201 00:12:51.920 --> 00:12:52.200 . 202 00:13:01.000 --> 00:13:01.280 . 203 00:13:01.280 --> 00:13:01.680 . 204 00:13:01.680 --> 00:13:01.860 . 205 00:13:01.860 --> 00:13:01.900 . 206 00:13:01.900 --> 00:13:01.960 . 207 00:13:01.960 --> 00:13:01.980 . 208 00:13:01.980 --> 00:13:02.020 . 209 00:13:02.020 --> 00:13:02.040 . 210 00:13:02.040 --> 00:13:02.060 . 211 00:13:02.060 --> 00:13:02.080 . 212 00:13:02.080 --> 00:13:02.100 . 213 00:13:02.100 --> 00:13:02.200 . 214 00:13:02.200 --> 00:13:02.300 . 215 00:13:02.300 --> 00:13:02.660 . 216 00:13:02.660 --> 00:13:02.940 . 217 00:13:12.700 --> 00:13:12.980 ! 218 00:13:19.480 --> 00:13:19.760 . 219 00:13:17.780 --> 00:13:18.780 . 220 00:13:23.620 --> 00:13:26.180 They never expected a soldier to walk on. 221 00:14:09.280 --> 00:14:14.660 Ladies and gentlemen, Ward Officer Pickman from the New Zealand Army Band. 222 00:14:15.780 --> 00:14:16.980 Okay, thank you, that'll do. 223 00:14:28.840 --> 00:14:32.760 Now I stopped it there because I'm walking around like a headless chook. 224 00:14:33.060 --> 00:14:37.120 I had an explosives charge strapped on my stomach, and just before I walked on, 225 00:14:37.260 --> 00:14:41.260 the switches were fired to connect the electric detonators, 226 00:14:41.420 --> 00:14:44.040 the wireless control detonators for this. 227 00:14:46.160 --> 00:14:48.440 So it's nice to have something of the unexpected. 228 00:14:49.780 --> 00:14:51.880 And it's also nice to do simple things. 229 00:14:52.200 --> 00:14:53.680 And I want to show you something remarkable. 230 00:14:54.940 --> 00:14:56.660 I've just got a rod of aluminium here. 231 00:14:57.000 --> 00:14:58.200 Now watch this. 232 00:15:02.860 --> 00:15:07.840 It went a bit fast for most people to see, and so I'll explain what happened. 233 00:15:08.040 --> 00:15:13.800 As I dropped this rod, that came in contact with the table. 234 00:15:14.740 --> 00:15:17.720 The bottom layers of the aluminium atoms, 235 00:15:19.780 --> 00:15:22.180 were halted, and the others were pushing down on them. 236 00:15:22.420 --> 00:15:25.880 Those bottom layers are now too close to the ones just above them. 237 00:15:27.580 --> 00:15:30.260 And so they push on the ones above them. 238 00:15:31.320 --> 00:15:35.160 And this pressure wave goes up to the end here. 239 00:15:35.600 --> 00:15:37.240 Now what happens at the top? 240 00:15:38.020 --> 00:15:40.100 We've got this layer of aluminium atoms, 241 00:15:41.680 --> 00:15:43.260 and outside them is air. 242 00:15:44.020 --> 00:15:47.400 Well, liquids and solids, we can't compress much, can we? 243 00:15:48.580 --> 00:15:49.720 We can't compress much. 244 00:15:49.720 --> 00:15:52.480 But if you've used a bike pump, you know you can compress a gas. 245 00:15:53.140 --> 00:15:55.680 Put another way, if you take a solid or a liquid, 246 00:15:56.420 --> 00:15:58.240 and turn it into a gas or a vapour, 247 00:15:58.880 --> 00:16:01.840 the volume change is about 700 times. 248 00:16:02.840 --> 00:16:05.560 Now I'm a physicist, 700 is a thousand, 249 00:16:06.320 --> 00:16:10.340 and a thousand is 10 that way, and 10 that way, and 10 that way. 250 00:16:11.300 --> 00:16:15.300 And so the atoms in the solid are touching, 251 00:16:15.420 --> 00:16:18.480 but in a gas, they're about 10 atomic diameters apart. 252 00:16:19.720 --> 00:16:22.720 So we have a density of about a thousandth of the solid. 253 00:16:23.780 --> 00:16:27.100 And so this top layer of atom, aluminium atoms, 254 00:16:27.400 --> 00:16:28.840 just goes hurtling up, 255 00:16:28.960 --> 00:16:32.220 and now it's too far away from the layer of atoms just below it. 256 00:16:32.780 --> 00:16:35.960 And so they are attracted up to it. 257 00:16:36.620 --> 00:16:37.800 And then the next layer. 258 00:16:38.040 --> 00:16:39.820 And so now we have this... 259 00:16:44.900 --> 00:16:45.380 other... 260 00:16:46.000 --> 00:16:46.480 other... 261 00:16:49.220 --> 00:16:49.700 other... 262 00:16:49.720 --> 00:16:52.760 This layer of a larger than normal, should be gap, 263 00:16:53.420 --> 00:16:54.200 propagates down, 264 00:16:55.780 --> 00:16:58.740 until finally the bottom layer leaps up. 265 00:16:58.940 --> 00:17:01.460 And it's only at that point this bar leaves the table. 266 00:17:02.080 --> 00:17:03.440 And you can actually measure this 267 00:17:03.440 --> 00:17:05.540 by just connecting the wire to this, 268 00:17:05.660 --> 00:17:07.360 and a piece of metal here to another wire, 269 00:17:08.040 --> 00:17:08.860 have an oscillator, 270 00:17:09.520 --> 00:17:10.940 and a little bit of electronics, 271 00:17:10.960 --> 00:17:12.560 so that when it first touches, 272 00:17:13.960 --> 00:17:16.240 we get electrical contact that starts the counter. 273 00:17:16.480 --> 00:17:17.800 And when it comes up again, 274 00:17:19.720 --> 00:17:21.140 jumps up again and breaks contact, 275 00:17:21.340 --> 00:17:22.260 then the counter stops. 276 00:17:23.280 --> 00:17:25.760 And you can find how long that wave took to go here. 277 00:17:25.920 --> 00:17:27.360 Now this is half a metre long. 278 00:17:30.340 --> 00:17:31.900 And I could have brought that apparatus. 279 00:17:34.740 --> 00:17:36.580 But to save weight, we don't need it. 280 00:17:38.160 --> 00:17:40.920 We can get the information out of the aluminium itself. 281 00:17:41.460 --> 00:17:43.240 Now we could torture the hell out of it, 282 00:17:43.260 --> 00:17:44.880 but it wouldn't squeal. 283 00:17:45.480 --> 00:17:47.480 But what it can't take is a bit of tickling. 284 00:17:57.500 --> 00:17:59.240 And aluminium is rather good. 285 00:18:00.580 --> 00:18:03.380 It doesn't have much attenuation of the sound. 286 00:18:04.840 --> 00:18:06.840 I just put a bit of rosin on my hands 287 00:18:06.840 --> 00:18:09.560 to get this shuddering grip along. 288 00:18:10.260 --> 00:18:12.080 So what happens, I'm holding it in the middle. 289 00:18:12.520 --> 00:18:15.800 The two ends are moving in and out. 290 00:18:16.540 --> 00:18:19.440 And so this is half of a wavelength long. 291 00:18:20.340 --> 00:18:24.360 So the sound we have is a metre wavelength long. 292 00:18:25.400 --> 00:18:26.560 Now the musicians in the audience, 293 00:18:26.800 --> 00:18:28.680 five kilohertz exactly, isn't it? 294 00:18:30.980 --> 00:18:36.100 That wave is covering this in one five thousandth of a second. 295 00:18:38.020 --> 00:18:41.580 The speed of sound in aluminium we've just measured 296 00:18:41.580 --> 00:18:43.860 is five kilometres every second. 297 00:18:44.120 --> 00:18:45.940 You could communicate down to the port, 298 00:18:46.020 --> 00:18:46.820 what in two seconds, 299 00:18:47.020 --> 00:18:48.920 by having a solid bar of aluminium 300 00:18:48.920 --> 00:18:49.640 and just tapping. 301 00:18:49.720 --> 00:18:51.120 You could even explain it with a bit of Morse code. 302 00:18:52.140 --> 00:18:54.800 So there are a lot of nice, simple, everyday physics. 303 00:18:55.140 --> 00:18:58.600 At the University we tend to go over the top 304 00:18:58.600 --> 00:19:00.260 with the latest advances 305 00:19:00.260 --> 00:19:02.280 and things that people really can't understand. 306 00:19:02.660 --> 00:19:04.280 And there's so much good stuff 307 00:19:05.060 --> 00:19:07.140 just in everyday life. 308 00:19:08.780 --> 00:19:10.000 I'll take another example. 309 00:19:15.520 --> 00:19:18.240 The receptors in our eye are all at the back 310 00:19:18.240 --> 00:19:22.200 and the curiosity of our eye is that the nerves 311 00:19:22.200 --> 00:19:24.440 and the blood vessels are in front of these. 312 00:19:24.760 --> 00:19:26.040 Light passes through them. 313 00:19:26.180 --> 00:19:27.180 We're not aware of that. 314 00:19:27.220 --> 00:19:28.680 It's one of these eye-brain interactions 315 00:19:28.680 --> 00:19:29.540 that's filtered out. 316 00:19:31.580 --> 00:19:34.780 Where these nerves and blood vessels go out, 317 00:19:35.860 --> 00:19:37.080 there are no receptors. 318 00:19:37.300 --> 00:19:38.380 So we are blind. 319 00:19:39.400 --> 00:19:41.060 What I'm going to do is close my left eye. 320 00:19:41.140 --> 00:19:45.460 I'm going to look at the exit sign at the back 321 00:19:46.180 --> 00:19:47.320 and take this orange 322 00:19:47.320 --> 00:19:48.220 and do a little bit of a look at the back. 323 00:19:48.220 --> 00:19:50.060 And just put it along that line 324 00:19:50.060 --> 00:19:52.020 and move it outwards 325 00:19:53.720 --> 00:19:55.140 and down a fraction 326 00:19:55.140 --> 00:19:56.020 and move it around. 327 00:19:57.540 --> 00:20:00.020 I cannot see that orange. 328 00:20:01.120 --> 00:20:04.740 The image of that is falling on the blind spot in my eye. 329 00:20:06.220 --> 00:20:08.360 So that means if a car was... 330 00:20:08.880 --> 00:20:09.900 Oh, how far away is this? 331 00:20:10.940 --> 00:20:13.460 Very roughly, that's one length 332 00:20:13.460 --> 00:20:15.660 compared with ten lengths. 333 00:20:16.020 --> 00:20:18.040 So one in ten, just crudely. 334 00:20:18.720 --> 00:20:22.220 How far away could a car be coming straight at me 335 00:20:22.220 --> 00:20:25.340 if I was intensely gazing in that one direction 336 00:20:25.340 --> 00:20:26.680 with only one eye open? 337 00:20:27.560 --> 00:20:30.300 The car's about two metres wide, 20 metres away. 338 00:20:30.640 --> 00:20:31.720 Don't stand a chance. 339 00:20:33.600 --> 00:20:35.940 It's easier when you first start 340 00:20:37.040 --> 00:20:38.960 to practice with something smaller. 341 00:20:39.360 --> 00:20:40.200 Nicely coloured. 342 00:20:41.060 --> 00:20:42.440 Much smaller orange. 343 00:20:43.540 --> 00:20:45.440 And you can even bring this in 344 00:20:45.440 --> 00:20:47.500 and just see how close you can get. 345 00:20:48.220 --> 00:20:49.640 Now this is a squash ball. 346 00:20:49.800 --> 00:20:51.480 How close can a squash ball be? 347 00:20:52.440 --> 00:20:55.640 And I won't see it if I'm staring intently there. 348 00:20:55.940 --> 00:20:56.980 About that far. 349 00:20:58.100 --> 00:21:01.180 You can understand why they are so dangerous 350 00:21:01.180 --> 00:21:02.960 but also because they're small enough 351 00:21:02.960 --> 00:21:05.440 to get into the eye socket 352 00:21:05.440 --> 00:21:06.760 and probably just splatter the eye. 353 00:21:07.900 --> 00:21:09.800 So there's a whole pile of little things 354 00:21:09.800 --> 00:21:12.340 about nature and the human body 355 00:21:12.340 --> 00:21:14.860 that we can point out to people 356 00:21:14.860 --> 00:21:16.580 without really... 357 00:21:18.400 --> 00:21:19.040 affecting them. 358 00:21:20.240 --> 00:21:21.120 Keeping it simple, 359 00:21:21.180 --> 00:21:22.960 we don't need expensive equipment. 360 00:21:24.340 --> 00:21:26.240 Oh, I forgot to have my drink. 361 00:21:28.900 --> 00:21:29.600 Oh, hang on. 362 00:21:29.680 --> 00:21:30.160 I tell you what, 363 00:21:30.200 --> 00:21:32.060 you'll still be worried about the bubbles in there, won't you? 364 00:21:34.800 --> 00:21:35.700 Hold on a tick. 365 00:21:39.060 --> 00:21:41.040 All I need is my Harry Potter wand. 366 00:21:41.740 --> 00:21:42.100 Oh. 367 00:21:42.820 --> 00:21:44.740 I keep losing it because bringing it to Australia, 368 00:21:44.940 --> 00:21:46.600 you're likely to get it pinched. 369 00:21:47.340 --> 00:21:48.200 And so I have to... 370 00:21:48.200 --> 00:21:50.040 I have to disguise it so no one will even think of it. 371 00:21:52.940 --> 00:21:54.960 And with a good knowledge of Latin, 372 00:21:56.980 --> 00:21:58.000 hocus pocus, 373 00:21:58.180 --> 00:21:59.480 bubblous is gonous. 374 00:22:00.480 --> 00:22:02.900 And that's transferred the bubbles to mine. 375 00:22:09.680 --> 00:22:11.940 So yours is perfectly safe to open now. 376 00:22:12.880 --> 00:22:13.420 Hmm. 377 00:22:16.420 --> 00:22:17.900 Now, the Science Teachers Conference, 378 00:22:18.200 --> 00:22:19.140 I did that, 379 00:22:19.220 --> 00:22:21.340 but there'd been a recent report 380 00:22:21.340 --> 00:22:23.340 of physicists with matter transfer. 381 00:22:25.300 --> 00:22:28.800 And so I did the hocus pocus with that. 382 00:22:32.440 --> 00:22:34.940 This was a trick shown to me by a magician. 383 00:22:36.880 --> 00:22:38.520 And they are fantastic 384 00:22:38.520 --> 00:22:41.020 at picking up on physical principles 385 00:22:42.280 --> 00:22:43.760 way before anyone else. 386 00:22:46.960 --> 00:22:48.180 And it's so simple. 387 00:22:48.200 --> 00:22:48.900 It's a simple course, isn't it? 388 00:22:48.900 --> 00:22:50.460 I'll only let you into the first part of it all. 389 00:22:51.060 --> 00:22:52.460 Why did that one not fizz up? 390 00:22:53.560 --> 00:22:55.640 Just do what Ed had, after he'd told me. 391 00:22:56.700 --> 00:22:57.740 I'm an experimentalist. 392 00:22:58.120 --> 00:22:59.020 Get a six pack. 393 00:22:59.660 --> 00:23:00.300 Shake them up. 394 00:23:00.380 --> 00:23:01.080 Now you'll feel it. 395 00:23:01.540 --> 00:23:02.760 There's a bit of air space above. 396 00:23:03.080 --> 00:23:04.180 And you shake the thing. 397 00:23:04.800 --> 00:23:08.080 And you'll feel this heavy mass of liquid thumping up and down. 398 00:23:08.520 --> 00:23:11.480 And after a few shakes, you no longer feel that. 399 00:23:11.520 --> 00:23:17.660 You've now got a diffused set of bubbles and gases come out of the liquid in a big way. 400 00:23:18.840 --> 00:23:21.340 But of course, the thing was in equilibrium to start with. 401 00:23:21.440 --> 00:23:23.760