1 00:00:09,720 --> 00:00:12,360 We are surrounded by order. 2 00:00:14,360 --> 00:00:16,320 Over the last 300 years, 3 00:00:16,320 --> 00:00:21,160 we've developed amazing new ways to harness energy. 4 00:00:22,360 --> 00:00:25,600 We've used this ability to transform our environment. 5 00:00:32,280 --> 00:00:37,000 But all these structures that we see around us are just 6 00:00:37,000 --> 00:00:42,120 one type of visible order that we've created here on planet Earth. 7 00:00:42,120 --> 00:00:45,000 There's another type of invisible order, 8 00:00:45,000 --> 00:00:48,960 every bit as complex that we are only now beginning to understand. 9 00:00:48,960 --> 00:00:53,800 It's something that nature has been harnessing for billions of years. 10 00:00:53,800 --> 00:00:56,600 Something we call information. 11 00:01:04,800 --> 00:01:08,080 The concept of information is a very strange one. 12 00:01:08,080 --> 00:01:12,320 It's actually a very difficult idea to get your head round. 13 00:01:12,320 --> 00:01:16,120 But in the journey to try and understand it, scientists 14 00:01:16,120 --> 00:01:21,440 would discover that information is a fundamental part of our universe. 15 00:01:24,480 --> 00:01:28,160 This film is the story of information. 16 00:01:28,160 --> 00:01:31,240 And the immense power released from manipulating it. 17 00:01:35,640 --> 00:01:39,520 It's the story of how we discovered the power of symbols. 18 00:01:41,800 --> 00:01:43,360 And how writing, codes 19 00:01:43,360 --> 00:01:48,680 and computers would revolutionise our understanding of the universe. 20 00:01:52,560 --> 00:01:57,280 It's the story of how, in a cosmos collapsing into disorder, 21 00:01:57,280 --> 00:02:01,320 information can be used to create order and structure. 22 00:02:51,040 --> 00:02:57,000 At first glance, information appears to be a very straightforward idea. 23 00:02:58,280 --> 00:03:01,320 It exists everywhere in our world. 24 00:03:01,320 --> 00:03:03,680 Our brains are filled with it. 25 00:03:03,680 --> 00:03:07,080 And we constantly exchange it between each other. 26 00:03:09,080 --> 00:03:11,720 But information has been one of the subtlest 27 00:03:11,720 --> 00:03:15,480 and most difficult concepts that science has had to grapple with. 28 00:03:16,960 --> 00:03:20,880 Understanding and harnessing it has been an extremely long 29 00:03:20,880 --> 00:03:22,720 and difficult process. 30 00:03:25,160 --> 00:03:30,880 The power of information would first be glimpsed over 5,000 years ago, 31 00:03:30,880 --> 00:03:33,880 when a revolutionary technology was developed. 32 00:03:33,880 --> 00:03:37,120 One that would set the modern world in motion. 33 00:03:44,960 --> 00:03:50,400 Over the years, mankind has come up with some pretty remarkable stuff. 34 00:03:50,400 --> 00:03:56,120 But of all humanity's inventions, there's one that really stands out. 35 00:03:56,120 --> 00:03:59,880 It's the most transformative, destructive, 36 00:03:59,880 --> 00:04:03,480 creative technology ever conceived. 37 00:04:03,480 --> 00:04:06,160 It is also one of the simplest. 38 00:04:06,160 --> 00:04:09,800 That invention is the written word. 39 00:04:12,760 --> 00:04:16,320 At its heart, writing is all about the transmission 40 00:04:16,320 --> 00:04:18,160 and storage of information. 41 00:04:31,760 --> 00:04:35,560 Words allow ideas to endure through time. 42 00:04:36,840 --> 00:04:40,080 These are some of the earliest texts in existence. 43 00:04:40,080 --> 00:04:44,360 They give us an incredible insight into the development of writing. 44 00:04:47,200 --> 00:04:50,640 I've come to meet one of the few people who can still read them - 45 00:04:51,720 --> 00:04:52,800 Dr Irving Finkel. 46 00:04:55,520 --> 00:04:59,400 We take writing so much for granted these days, 47 00:04:59,400 --> 00:05:02,040 it's easy to forget that it was invented. 48 00:05:02,040 --> 00:05:03,120 It certainly was. 49 00:05:03,120 --> 00:05:04,760 How did it first come about? 50 00:05:04,760 --> 00:05:08,520 The earliest writing that we have is written on clay tablets 51 00:05:08,520 --> 00:05:12,200 and it comes from Iraq, Ancient Mesopotamia. 52 00:05:12,200 --> 00:05:14,560 It comes from the culture of the culture of the Sumerians. 53 00:05:14,560 --> 00:05:17,920 What happened here was that they started off with purely 54 00:05:17,920 --> 00:05:20,760 pictographic signs to express an idea. 55 00:05:20,760 --> 00:05:24,960 This lasted for quite a long time, until it occurred to somebody, 56 00:05:24,960 --> 00:05:28,480 perhaps accidentally, that what you could do is make one of these 57 00:05:28,480 --> 00:05:32,280 graphic symbols on the surface of the clay not for what it 58 00:05:32,280 --> 00:05:37,800 looked like but for the sound it represented. 59 00:05:37,800 --> 00:05:41,440 So not a picture of an object, a picture of a sound? 60 00:05:41,440 --> 00:05:45,040 That's what we always called the giant leap for mankind. 61 00:05:49,320 --> 00:05:52,000 By combining different sounding pictures, 62 00:05:52,000 --> 00:05:56,680 the ancient Mesopotamians could express any idea imaginable. 63 00:05:58,360 --> 00:06:01,280 The essence of their breakthrough was to see, for example, 64 00:06:01,280 --> 00:06:03,160 that a picture of an eye 65 00:06:03,160 --> 00:06:08,280 and a picture of a deer didn't have to mean an eye and a deer. 66 00:06:09,520 --> 00:06:13,000 The pictures could be used simply for the sounds that they made. 67 00:06:13,000 --> 00:06:14,880 In this case, idea. 68 00:06:19,400 --> 00:06:21,480 Once this system was discovered, 69 00:06:21,480 --> 00:06:25,360 it meant anything that could be spoken, even the most strange 70 00:06:25,360 --> 00:06:30,200 or abstract thoughts could be transformed into symbols. 71 00:06:31,600 --> 00:06:35,280 Information could now live outside of the human brain. 72 00:06:36,520 --> 00:06:40,080 This meant it could endure over vast spans of time. 73 00:06:41,760 --> 00:06:45,320 It was an idea that fascinated the ancient Mesopotamians. 74 00:06:49,920 --> 00:06:56,680 This lovely tablet here, this king lived in about 2100 BC. 75 00:06:56,680 --> 00:06:59,320 He buried this in the foundations of his temple as a message 76 00:06:59,320 --> 00:07:00,840 for the future. 77 00:07:00,840 --> 00:07:07,160 This King Ur-Nammu, the powerful male, King of Sumer and Akkad - 78 00:07:07,160 --> 00:07:11,000 that's the south and north part of Ancient Mesopotamia. 79 00:07:11,000 --> 00:07:15,440 Her house - he built for her and he even restored it afterwards. 80 00:07:15,440 --> 00:07:16,880 This is a proud thing. 81 00:07:16,880 --> 00:07:19,560 He wants everybody to know about it 82 00:07:19,560 --> 00:07:21,760 and this is a real message for the future. 83 00:07:21,760 --> 00:07:24,520 What's so remarkable for me 84 00:07:24,520 --> 00:07:28,280 is this is information stored on clay for thousands of years. 85 00:07:28,280 --> 00:07:32,280 Yes. Ideas that someone had 4,000 years ago are still there. 86 00:07:32,280 --> 00:07:36,840 You have ideas, you have speech, human hopes, literature, 87 00:07:36,840 --> 00:07:41,080 prayers - all these sorts of outpourings of the human soul 88 00:07:41,080 --> 00:07:42,680 fixed for ever in clay. 89 00:07:50,320 --> 00:07:52,800 By turning sounds into symbols, 90 00:07:52,800 --> 00:07:57,360 the Mesopotamian scribes had discover that information could be 91 00:07:57,360 --> 00:08:00,760 changed very easily from one form to another. 92 00:08:05,360 --> 00:08:08,120 From something that existed as spoken sounds, 93 00:08:08,120 --> 00:08:12,360 to something that existed as symbols on clay tablets. 94 00:08:13,960 --> 00:08:16,400 This was just the beginning. 95 00:08:16,400 --> 00:08:20,160 Humans were yet to realise the true power of symbols. 96 00:08:38,120 --> 00:08:42,840 For 4,000 years, writing was pretty much the only 97 00:08:42,840 --> 00:08:46,120 information technology people used. 98 00:08:46,120 --> 00:08:49,760 But in the 19th century, during the great Industrial Revolution, 99 00:08:49,760 --> 00:08:51,960 things would begin to change. 100 00:08:53,680 --> 00:08:56,200 In the maelstrom of ideas and inventions, 101 00:08:56,200 --> 00:09:00,400 a series of seemingly unconnected technologies would emerge 102 00:09:00,400 --> 00:09:05,360 that all began to hint at the immense power of information. 103 00:09:07,120 --> 00:09:10,320 These technologies would all come from very practical, 104 00:09:10,320 --> 00:09:13,280 very un-theoretical origins. 105 00:09:13,280 --> 00:09:16,560 They would start to reveal that information was a much deeper 106 00:09:16,560 --> 00:09:20,800 and more powerful concept than anyone had realised. 107 00:09:23,280 --> 00:09:27,760 One of the first of a new breed of information technologies would be 108 00:09:27,760 --> 00:09:31,360 developed in the French city of Lyon at the end of the 18th century. 109 00:09:37,280 --> 00:09:41,360 18th-century Lyon was home to some of the best craftsmen in the world. 110 00:09:41,360 --> 00:09:43,840 It was also a place of great opulence, 111 00:09:43,840 --> 00:09:46,720 grandeur and, above all, money. 112 00:09:46,720 --> 00:09:49,280 Thanks to the rich and fashionable aristocrats 113 00:09:49,280 --> 00:09:51,320 and bankers who lived there, 114 00:09:51,320 --> 00:09:55,760 it would become home to the greatest silk-weaving industry in the world. 115 00:09:55,760 --> 00:09:58,400 Almost a third of the city's inhabitants worked in 116 00:09:58,400 --> 00:10:03,560 the silk industry, and it was home to over 14,000 looms. 117 00:10:14,000 --> 00:10:16,360 This is brocade. 118 00:10:16,360 --> 00:10:20,040 The material that made Lyon famous. 119 00:10:20,040 --> 00:10:23,360 It's a beautiful and intricately woven fabric that, 120 00:10:23,360 --> 00:10:27,080 as you might imagine, is incredibly labour intensive to produce. 121 00:10:27,080 --> 00:10:30,680 A two-man team, working flat out for a day, 122 00:10:30,680 --> 00:10:34,320 could at best produce about an inch of this amazing stuff. 123 00:10:40,560 --> 00:10:44,360 The demand for the fine fabrics of Lyon was immense. 124 00:10:44,360 --> 00:10:46,960 But the silk weaving process was painful slow. 125 00:10:50,000 --> 00:10:54,640 But thanks to a soldier and weaver named Joseph Marie Jaquard, 126 00:10:54,640 --> 00:10:58,520 a device will be developed to help speed up weaving. 127 00:10:58,520 --> 00:11:03,360 In the process, it would reveal a fundamental truth about information. 128 00:11:15,840 --> 00:11:20,720 Building on the work of a number of others, in 1804 Jaquard 129 00:11:20,720 --> 00:11:23,480 patented his invention. 130 00:11:23,480 --> 00:11:27,120 At the time, the loom was the most complex mechanism 131 00:11:27,120 --> 00:11:28,560 ever built by humankind 132 00:11:38,760 --> 00:11:42,040 Jaquard's loom was a miracle of ingenuity. 133 00:11:42,040 --> 00:11:45,640 You see, he had designed a single machine, which without any 134 00:11:45,640 --> 00:11:50,120 alteration to its construction - its hardware, to use a modem term - 135 00:11:50,120 --> 00:11:54,640 could be programmed to weave any pattern a designer could think up. 136 00:11:54,640 --> 00:11:58,080 It fact, it could produce a whole range of silk designs 137 00:11:58,080 --> 00:12:00,480 with barely a pause in production. 138 00:12:00,480 --> 00:12:04,360 Jaquard had found the holy grail of weaving. 139 00:12:04,360 --> 00:12:08,200 And the secret was a simple punched card. 140 00:12:14,480 --> 00:12:18,320 The punched card held within it the essence of the designs 141 00:12:18,320 --> 00:12:20,200 that the loom would weave. 142 00:12:25,520 --> 00:12:28,600 When these punched cards were fed into the loom 143 00:12:28,600 --> 00:12:32,320 they would act to lower and lift the relevant threads... 144 00:12:36,160 --> 00:12:38,920 ..recreating the pattern in silk. 145 00:12:45,200 --> 00:12:49,400 Any design you could think of could be broken down and translated into 146 00:12:49,400 --> 00:12:53,120 a series of punch cards that could then woven by the loom. 147 00:13:00,560 --> 00:13:04,000 Information was being translated from 148 00:13:04,000 --> 00:13:07,520 picture to punch card to the finished fabric. 149 00:13:11,960 --> 00:13:14,800 It's a machine for weaving textiles, that's its task, 150 00:13:14,800 --> 00:13:18,560 but there is nothing specific about what textile it should weave. 151 00:13:18,560 --> 00:13:21,120 That is contained in the information, 152 00:13:21,120 --> 00:13:23,160 which is encoded on the cards. 153 00:13:23,160 --> 00:13:28,040 So if you like, the cards, programme it, that is to say instruct it 154 00:13:28,040 --> 00:13:32,320 what to do. And this has huge resonances for what came later. 155 00:13:33,920 --> 00:13:37,760 Jaquard's Loom revolutionised the silk industry. 156 00:13:37,760 --> 00:13:41,600 But at its heart was something deeper, something more universal 157 00:13:41,600 --> 00:13:46,160 than its industrial origins and its ability to speed up weaving. 158 00:13:46,160 --> 00:13:51,160 The loom revealed the power of abstracting information. 159 00:13:51,160 --> 00:13:55,040 It showed you can take the essence of something, extract the vital 160 00:13:55,040 --> 00:13:58,080 information and represent it in another form. 161 00:14:04,120 --> 00:14:08,160 Writing had revealed you could use a set of symbols to capture 162 00:14:08,160 --> 00:14:10,360 spoken language. 163 00:14:10,360 --> 00:14:14,600 Now, Jaquard had shown that with just two symbols - 164 00:14:14,600 --> 00:14:18,400 a hole or a blank space, it was possible to capture 165 00:14:18,400 --> 00:14:21,560 the information in any picture imaginable. 166 00:14:27,920 --> 00:14:32,640 This is a portrait of Jaquard that's been woven in silk. 167 00:14:32,640 --> 00:14:37,480 It's spectacularly detailed with hundreds of thousands of stitches. 168 00:14:37,480 --> 00:14:42,560 Yet all the information you need to capture this life-like image can be 169 00:14:42,560 --> 00:14:48,680 stored in a series of punched cards. 24,000 of them to be precise. 170 00:15:04,280 --> 00:15:09,360 This picture is a fantastic example of a really far-reaching idea. 171 00:15:10,640 --> 00:15:12,720 That the simplest of systems - 172 00:15:12,720 --> 00:15:16,480 in this case, cards with a series of holes punched in them - 173 00:15:16,480 --> 00:15:23,160 can capture the essence of something much, much more complicated. 174 00:15:25,400 --> 00:15:30,880 If 24,000 punched cards could create an image like this... 175 00:15:34,160 --> 00:15:37,080 What would happen if you had 24 million? 176 00:15:40,640 --> 00:15:43,160 Or 24 trillion cards? 177 00:15:50,440 --> 00:15:52,920 What new types of complex information 178 00:15:52,920 --> 00:15:56,280 might be able to be captured and represented? 179 00:16:03,480 --> 00:16:06,640 Jacquard had stumbled on an incredibly deep 180 00:16:06,640 --> 00:16:08,280 and far-reaching idea. 181 00:16:14,000 --> 00:16:18,360 As long as you have enough of them, simple symbols can be used 182 00:16:18,360 --> 00:16:22,040 to describe anything in the entire universe. 183 00:16:39,720 --> 00:16:42,800 Translating information into abstract symbols 184 00:16:42,800 --> 00:16:47,880 to store and process, had proven to be an extremely powerful idea. 185 00:16:49,120 --> 00:16:51,760 But the way information was sent, 186 00:16:51,760 --> 00:16:56,000 the way it was communicated, hadn't changed for thousands of years. 187 00:16:57,080 --> 00:16:59,240 The world before telecommunications technology 188 00:16:59,240 --> 00:17:00,880 was a very different place, 189 00:17:00,880 --> 00:17:04,520 cos you could only send messages as fast as you could send objects. 190 00:17:04,520 --> 00:17:07,200 You'd write a message on a piece of paper or something like that 191 00:17:07,200 --> 00:17:09,800 and then you'd give it to somebody who could run very fast, 192 00:17:09,800 --> 00:17:12,040 or could go on horse or on a ship very fast. 193 00:17:12,040 --> 00:17:14,280 The point was you could only send information as fast as 194 00:17:14,280 --> 00:17:15,520 you could send matter. 195 00:17:17,720 --> 00:17:21,120 But in the 19th century, the speed at which information 196 00:17:21,120 --> 00:17:24,480 could be sent would dramatically increase, 197 00:17:24,480 --> 00:17:29,440 thanks to an incredible new information-carrying medium - 198 00:17:29,440 --> 00:17:32,240 electricity. 199 00:17:36,160 --> 00:17:38,800 Very soon after electricity was discovered, 200 00:17:38,800 --> 00:17:44,680 excitement grew about its potential as a medium to transmit messages. 201 00:17:44,680 --> 00:17:48,640 It seemed that if it could be controlled and summoned at will, 202 00:17:48,640 --> 00:17:52,880 electricity would be the perfect medium for sending information. 203 00:17:54,720 --> 00:17:57,360 Electricity seemed to offer many advantages 204 00:17:57,360 --> 00:18:00,200 as a way of sending messages. 205 00:18:00,200 --> 00:18:04,000 It was sent down a wire which means it could pretty much go anywhere. 206 00:18:04,000 --> 00:18:06,680 It wasn't affected by bad weather conditions 207 00:18:06,680 --> 00:18:10,800 and most importantly, it could move very quickly. 208 00:18:10,800 --> 00:18:14,640 But there was one big problem facing those in the early 19th century 209 00:18:14,640 --> 00:18:18,520 who wanted to use electricity as a means to communicate. 210 00:18:18,520 --> 00:18:23,560 How could such a simple signal be used to send complex messages? 211 00:18:26,600 --> 00:18:29,480 Here in the Science Museum archive, 212 00:18:29,480 --> 00:18:32,480 they have one of the most impressive collections 213 00:18:32,480 --> 00:18:36,360 of early electronic communications technology in the world. 214 00:18:41,000 --> 00:18:42,880 Here are just some of the early devices 215 00:18:42,880 --> 00:18:46,240 designed to send signals using electricity. 216 00:18:46,240 --> 00:18:48,280 This one's particularly fun. 217 00:18:48,280 --> 00:18:52,320 It was developed in 1809 in Bavaria by Samuel Soemmering. 218 00:18:52,320 --> 00:18:54,480 So if the sender wants to send letter A, 219 00:18:54,480 --> 00:18:57,920 he sends a current through that corresponding wire. 220 00:18:57,920 --> 00:19:01,320 At the receiver's end is a tank full of liquid 221 00:19:01,320 --> 00:19:04,000 and electric current forces a chemical reaction 222 00:19:04,000 --> 00:19:07,840 causing bubbles to appear above the corresponding letter A. 223 00:19:07,840 --> 00:19:11,760 The whole process is ingenious, if a little laborious. 224 00:19:11,760 --> 00:19:14,760 But what's really fun is that the sender has to let the receiver know 225 00:19:14,760 --> 00:19:16,960 he's about to send a signal. 226 00:19:16,960 --> 00:19:20,040 He does that by sending extra electric currents 227 00:19:20,040 --> 00:19:21,640 so that more bubbles appear, 228 00:19:21,640 --> 00:19:25,520 forcing an arm upwards which releases a ball... 229 00:19:25,520 --> 00:19:27,160 BELL RINGS 230 00:19:27,160 --> 00:19:29,360 ..and triggers a bell. 231 00:19:34,840 --> 00:19:38,800 As you can imagine, this wouldn't be the quickest of systems. 232 00:19:38,800 --> 00:19:42,160 After Soemmering, all sorts of approaches were taken 233 00:19:42,160 --> 00:19:47,240 in trying to crack the problem of sending messages using electricity. 234 00:19:48,240 --> 00:19:52,120 But they all suffered from having over-complex codes. 235 00:19:54,000 --> 00:19:58,040 These devices, each cunning and innovative in its own way, 236 00:19:58,040 --> 00:20:01,640 were all destined for the scrap heap of history. 237 00:20:01,640 --> 00:20:05,120 And that's because in the 1840s, they were superseded by a way 238 00:20:05,120 --> 00:20:09,440 of sending signals that still endures to this day. 239 00:20:09,440 --> 00:20:14,280 It was developed by artist and entrepreneur Samuel Morse, 240 00:20:14,280 --> 00:20:16,920 together with his colleague Alfred Vale. 241 00:20:16,920 --> 00:20:20,600 What was so special about their system wasn't the technology 242 00:20:20,600 --> 00:20:23,200 that was used to carry their messages, 243 00:20:23,200 --> 00:20:26,680 but the incredibly simple and effective code 244 00:20:26,680 --> 00:20:28,280 they used to send them. 245 00:20:37,640 --> 00:20:42,680 Just like Jacquard's punch cards, the genius of Morse and Vale's code 246 00:20:42,680 --> 00:20:44,000 lay in its simplicity. 247 00:20:46,160 --> 00:20:50,000 Using a collection of short and long pulses of electrical current, 248 00:20:50,000 --> 00:20:53,040 they could spell out the letters of the alphabet. 249 00:20:55,720 --> 00:20:58,200 Vale suggested that the most frequent letters 250 00:20:58,200 --> 00:21:00,960 in the English language get the shortest code. 251 00:21:04,000 --> 00:21:07,280 So an E is sent like this. 252 00:21:09,520 --> 00:21:12,280 While an X is sent like this. 253 00:21:13,360 --> 00:21:17,240 This means that messages can be sent quickly and efficiently. 254 00:21:18,920 --> 00:21:21,680 Figuring out the code part of it, the software if you like, 255 00:21:21,680 --> 00:21:25,400 was as complicated as figuring out the hardware side of things 256 00:21:25,400 --> 00:21:28,960 with the batteries and the wires, and together they made an entirely new 257 00:21:28,960 --> 00:21:31,360 technology which is the electric telegraph. 258 00:21:33,680 --> 00:21:36,480 The telegraph had once again revealed the power 259 00:21:36,480 --> 00:21:40,600 of translating information from one medium to another. 260 00:21:42,400 --> 00:21:47,120 Information had at first been fixed in human brains. 261 00:21:47,120 --> 00:21:52,560 Then held in symbols in clay and paper and punched cards. 262 00:21:54,440 --> 00:21:59,000 Now, thanks to Morse, information could reside in electricity 263 00:21:59,000 --> 00:22:03,040 and this made it unimaginably lighter and quicker 264 00:22:03,040 --> 00:22:04,440 than it had every been before. 265 00:22:09,040 --> 00:22:11,760 In just a few short years, the telegraph network 266 00:22:11,760 --> 00:22:14,680 would spread around the entire globe, 267 00:22:14,680 --> 00:22:18,400 laying the foundations of the modern information age. 268 00:22:27,520 --> 00:22:33,320 Between them, Jacquard and Morse had found new novel ways to manipulate, 269 00:22:33,320 --> 00:22:36,240 process and transmit information. 270 00:22:36,240 --> 00:22:40,120 What had begun with the invention of writing thousands of years ago 271 00:22:40,120 --> 00:22:43,960 had culminated in the binding of the entire planet 272 00:22:43,960 --> 00:22:47,880 in a lattice of wires carrying highly abstracted information 273 00:22:47,880 --> 00:22:50,040 at incredible speeds. 274 00:22:50,040 --> 00:22:53,000 For people at the end of the 19th century 275 00:22:53,000 --> 00:22:56,800 it may have seemed that humanity's ability to manipulate 276 00:22:56,800 --> 00:23:00,480 and transmit information was at its zenith. 277 00:23:00,480 --> 00:23:03,280 They couldn't have been more wrong. 278 00:23:03,280 --> 00:23:06,680 Information would reveal itself to be a more important, 279 00:23:06,680 --> 00:23:10,960 more fundamental concept than anyone could have imagined. 280 00:23:13,840 --> 00:23:16,400 It would soon become apparent that information 281 00:23:16,400 --> 00:23:19,920 wasn't just about human communication. 282 00:23:19,920 --> 00:23:23,160 It was a much further-reaching idea than that. 283 00:23:24,440 --> 00:23:28,040 The true nature of information would first be hinted at 284 00:23:28,040 --> 00:23:29,880 thanks to a strange problem, 285 00:23:29,880 --> 00:23:33,640 one dreamed up by a brilliant Scottish physicist 286 00:23:33,640 --> 00:23:36,360 who appeared to be thinking about something else entirely. 287 00:23:52,560 --> 00:23:57,480 James Clerk Maxwell was one of the great minds of the 19th century. 288 00:24:01,160 --> 00:24:04,640 Among his many interests, Maxwell became fascinated 289 00:24:04,640 --> 00:24:07,880 by the science of thermodynamics - 290 00:24:07,880 --> 00:24:10,280 the study of heat and motion that had sprung up 291 00:24:10,280 --> 00:24:11,800 with the birth of the steam engine. 292 00:24:18,960 --> 00:24:21,600 Maxwell was one of the first to understand 293 00:24:21,600 --> 00:24:25,120 that heat is really just the motion of molecules. 294 00:24:25,120 --> 00:24:29,680 The hotter something is, the faster its molecules are moving. 295 00:24:31,800 --> 00:24:36,120 This idea would lead Maxwell to dream up a very bizarre 296 00:24:36,120 --> 00:24:40,120 thought experiment in which information played a crucial role. 297 00:24:47,680 --> 00:24:51,760 Maxwell theorised that simply by knowing what's going on 298 00:24:51,760 --> 00:24:57,200 inside a box full of air, it'll be possible to make one half hotter 299 00:24:57,200 --> 00:24:59,800 and the other half colder. 300 00:24:59,800 --> 00:25:03,080 Think of it like building an oven next to a fridge 301 00:25:03,080 --> 00:25:05,000 without using any energy. 302 00:25:17,040 --> 00:25:22,000 It sounds crazy, but Maxwell's argument was extremely persuasive. 303 00:25:22,000 --> 00:25:23,440 It goes like this. 304 00:25:23,440 --> 00:25:27,040 Imagine a small demon perched on to of the box, 305 00:25:27,040 --> 00:25:30,880 who has such excellent eye sight that he could observe accurately 306 00:25:30,880 --> 00:25:34,600 the motion of all the molecules of air inside the box. 307 00:25:51,640 --> 00:25:53,280 Now, crucially, 308 00:25:53,280 --> 00:25:58,400 he's in control of a partition that divides the box into two halves. 309 00:25:58,400 --> 00:26:02,440 Every time he sees a fast-moving molecule approaching the partition 310 00:26:02,440 --> 00:26:07,920 from the right-hand side he opens it up, allowing it through to the left. 311 00:26:07,920 --> 00:26:11,560 And every time he sees a slow moving molecule approaching the partition 312 00:26:11,560 --> 00:26:15,000 from the left, he opens it up, allowing the molecule 313 00:26:15,000 --> 00:26:16,160 through to the right. 314 00:26:28,440 --> 00:26:31,200 Now, you can see what's going to happen. 315 00:26:31,200 --> 00:26:35,720 Over time, all the fast-moving hot molecules will accumulate 316 00:26:35,720 --> 00:26:38,000 on the left-hand side of the box, 317 00:26:38,000 --> 00:26:41,400 and all the slow-moving cold molecules on the right. 318 00:26:42,680 --> 00:26:46,880 Crucially, the demon has done this sorting with nothing more 319 00:26:46,880 --> 00:26:50,160 than information about the motion of the molecules. 320 00:26:53,680 --> 00:26:58,600 Maxwell's demon seemed to say that just by having information 321 00:26:58,600 --> 00:27:02,880 about the molecules, you could create order from disorder. 322 00:27:04,240 --> 00:27:07,880 This idea flew in the face of 19th-century thinking. 323 00:27:12,760 --> 00:27:16,280 The science of thermodynamics had shown very clearly 324 00:27:16,280 --> 00:27:21,240 that over time, the entropy of the universe, its disorder, 325 00:27:21,240 --> 00:27:26,280 would always increase. Things were destined to fall apart. 326 00:27:31,920 --> 00:27:36,120 But the demon seemed to suggest that you could put things back together 327 00:27:36,120 --> 00:27:39,320 without using any energy at all. 328 00:27:39,320 --> 00:27:43,840 Just by using information, you could create order. 329 00:27:48,080 --> 00:27:52,040 It would prove to be a fiendishly difficult problem to solve, 330 00:27:52,040 --> 00:27:55,960 not least because the brilliant Maxwell had come up with an idea 331 00:27:55,960 --> 00:27:58,520 far, far ahead of its time. 332 00:28:01,680 --> 00:28:05,360 It's amazing, the impact that he had on physics, 333 00:28:05,360 --> 00:28:08,960 and that he came up with this very intricate concept 334 00:28:08,960 --> 00:28:15,680 and that he already in some sense pre-anticipated the notion 335 00:28:15,680 --> 00:28:18,520 of information. It wasn't actually there at the time, 336 00:28:18,520 --> 00:28:19,760 there was no such thing. 337 00:28:22,920 --> 00:28:25,280 I think this idea was astonishing. 338 00:28:25,280 --> 00:28:28,840 He didn't really have a resolution, he raised it as a concern 339 00:28:28,840 --> 00:28:30,280 and he left it open. 340 00:28:31,520 --> 00:28:35,640 And I think what followed is more or less 120 years 341 00:28:35,640 --> 00:28:39,560 of extremely exciting debate and development 342 00:28:39,560 --> 00:28:42,680 to try to resolve and address this concern. 343 00:28:54,040 --> 00:28:58,120 So what was going on with Maxwell's demon? 344 00:28:58,120 --> 00:29:00,480 It may sound far-fetched and fanciful, 345 00:29:00,480 --> 00:29:04,000 but imagine the possibilities if we could build a machine 346 00:29:04,000 --> 00:29:08,480 in the real world that could mimic the actions of the Demon. 347 00:29:08,480 --> 00:29:12,760 I could use it to heat a cup of coffee, or run an engine, 348 00:29:12,760 --> 00:29:19,040 or power a city all using nothing more than pure information. 349 00:29:19,040 --> 00:29:21,280 It's as though we could create order in the universe 350 00:29:21,280 --> 00:29:22,760 without expending any energy. 351 00:29:23,960 --> 00:29:28,120 Scientists felt intuitively that it had to be wrong. 352 00:29:28,120 --> 00:29:33,040 The problem was it would take over 100 years to solve the problem. 353 00:29:39,680 --> 00:29:41,840 While Maxwell's riddle rumbled on, 354 00:29:41,840 --> 00:29:44,440 something quite unexpected was to happen, 355 00:29:44,440 --> 00:29:49,640 a new device was dreamt up that could perform quite incredible 356 00:29:49,640 --> 00:29:53,560 and complex tasks simply by processing information. 357 00:29:53,560 --> 00:29:56,800 What's more, this was a device that could actually be built. 358 00:29:56,800 --> 00:30:01,480 The machine would come to be known as the computer, and the idea 359 00:30:01,480 --> 00:30:06,200 behind it came from a quite remarkable and visionary scientist. 360 00:30:19,400 --> 00:30:24,080 Alan Turing was the first person to conceive of the modern computer, 361 00:30:24,080 --> 00:30:30,360 a machine whose sole function is to manipulate and process information. 362 00:30:30,360 --> 00:30:34,600 A machine that harnesses the power of abstract symbols. 363 00:30:34,600 --> 00:30:38,280 A machine that enables almost every aspect of the modern world. 364 00:30:40,720 --> 00:30:45,040 Turing's incredible idea would first appear in a now-legendary 365 00:30:45,040 --> 00:30:49,200 mathematical paper published in 1936. 366 00:30:52,480 --> 00:30:57,120 In his brief life, Alan Turing brought fresh, groundbreaking ideas 367 00:30:57,120 --> 00:31:00,000 to a whole range of topics, 368 00:31:00,000 --> 00:31:03,240 from cryptography through to biology. 369 00:31:03,240 --> 00:31:06,880 The sheer breadth of his thinking is breathtaking. 370 00:31:08,120 --> 00:31:12,120 But for most scientists, it's the concepts he outlined 371 00:31:12,120 --> 00:31:19,320 in these 36 pages that mark him out as truly special. 372 00:31:19,320 --> 00:31:24,360 It's this work that makes him worthy of the title "Genius". 373 00:31:26,880 --> 00:31:30,280 Published when Turing was just 24 years old, 374 00:31:30,280 --> 00:31:31,920 On Computable Numbers 375 00:31:31,920 --> 00:31:34,160 With An Application To The Entscheidungsproblem 376 00:31:34,160 --> 00:31:36,440 tackles the foundations of mathematical logic. 377 00:31:40,360 --> 00:31:44,680 What's amazing about it is that the idea for the modern computer 378 00:31:44,680 --> 00:31:50,000 emerged simply as a consequence of Turing's brilliant reasoning. 379 00:31:50,000 --> 00:31:52,000 He was thinking about something else entirely, 380 00:31:52,000 --> 00:31:54,440 he wasn't, you know, sitting there thinking, 381 00:31:54,440 --> 00:31:57,200 "I want to try and invent the modern computer," he was thinking 382 00:31:57,200 --> 00:32:00,960 about this very abstract problem in the foundations of mathematics. 383 00:32:00,960 --> 00:32:04,720 And the computer kind fell sideways out of that research, 384 00:32:04,720 --> 00:32:06,000 completely unexpectedly. 385 00:32:06,000 --> 00:32:10,880 I mean, nobody could have guessed that Turing's very abstract, 386 00:32:10,880 --> 00:32:14,520 abstruse research in the foundations of mathematics could produce 387 00:32:14,520 --> 00:32:18,720 anything of any practical value whatsoever, let alone a machine that 388 00:32:18,720 --> 00:32:22,280 was going to change the lives of, you know, nearly everyone on the planet. 389 00:32:24,920 --> 00:32:28,200 Turing had set out to understand if certain processes 390 00:32:28,200 --> 00:32:32,760 in mathematics could be done simply by following a set of rules. 391 00:32:32,760 --> 00:32:37,440 And this is what would get him thinking about computers. 392 00:32:40,000 --> 00:32:44,640 In 1936, the word "computer" had a very different meaning 393 00:32:44,640 --> 00:32:46,440 to what it does today. 394 00:32:46,440 --> 00:32:49,880 It meant a real person with a pencil and paper, 395 00:32:49,880 --> 00:32:52,520 engaged in arithmetical calculations. 396 00:32:53,600 --> 00:32:57,000 Banks hired many such people, often women, 397 00:32:57,000 --> 00:32:59,200 to work out interest payments. 398 00:32:59,200 --> 00:33:03,280 The Inland Revenue employed them to work out how much tax to charge. 399 00:33:03,280 --> 00:33:06,720 Observatories hired them to calculate navigational data. 400 00:33:08,480 --> 00:33:11,880 Human computers were vital to the modern world, 401 00:33:11,880 --> 00:33:14,880 dealing with the huge amounts of information produced 402 00:33:14,880 --> 00:33:18,760 as science and industry grew ever more complex. 403 00:33:22,720 --> 00:33:26,720 What Turing did in his 1936 paper was ask a simple 404 00:33:26,720 --> 00:33:28,760 but profound question. 405 00:33:28,760 --> 00:33:34,560 "What goes on in the mind of a person carrying out a computation?" 406 00:33:34,560 --> 00:33:38,880 To do this, he first had to discard all the superfluous detail, 407 00:33:38,880 --> 00:33:43,920 so that only the very essence of the process of computation remained. 408 00:33:43,920 --> 00:33:47,120 So, first off went the inkpot. 409 00:33:47,120 --> 00:33:49,800 Then the pen, then the slide-rule. 410 00:33:49,800 --> 00:33:52,280 Then the pencils and the pads of paper. 411 00:33:52,280 --> 00:33:55,000 All these things made it easier, but none of them 412 00:33:55,000 --> 00:33:59,960 were absolutely crucial to the person carrying out the computation. 413 00:34:04,040 --> 00:34:09,080 Now Turing asked, "What goes on in the brain of a human computer?" 414 00:34:09,080 --> 00:34:11,720 It's a vastly complex biological system, 415 00:34:11,720 --> 00:34:15,840 capable of consciousness, thoughts and insights, but to Turing, 416 00:34:15,840 --> 00:34:20,120 none of these was critical to the process of computation either. 417 00:34:20,120 --> 00:34:23,760 Turing realised that to compute something, 418 00:34:23,760 --> 00:34:27,160 a set of rules had to be followed precisely. 419 00:34:27,160 --> 00:34:29,080 That was all. 420 00:34:30,840 --> 00:34:33,080 It takes the higher level intelligence 421 00:34:33,080 --> 00:34:35,960 that was presupposed to be involved in calculation, 422 00:34:35,960 --> 00:34:40,680 which was thinking, and says you can have a mechanical process - 423 00:34:40,680 --> 00:34:43,680 and by mechanical, he means an unthinking process - 424 00:34:43,680 --> 00:34:45,240 to perform the same act. 425 00:34:45,240 --> 00:34:49,400 And therefore eliminates the necessity of human agency, 426 00:34:49,400 --> 00:34:51,520 with all its high-level functions. 427 00:34:51,520 --> 00:34:54,840 And that is what is revolutionary about what he tries to do. 428 00:34:58,120 --> 00:35:02,000 Turing's brilliant mind saw that any calculation had two aspects... 429 00:35:03,560 --> 00:35:08,840 The data, and the instructions for what to do with the data. 430 00:35:08,840 --> 00:35:11,880 And this would be the key to his insight. 431 00:35:13,920 --> 00:35:18,160 Turing had to find a way of getting machines to understand instructions 432 00:35:18,160 --> 00:35:21,360 like "add," "subtract," "multiply," "divide" 433 00:35:21,360 --> 00:35:24,720 and so on, in the same way that humans do. 434 00:35:24,720 --> 00:35:27,720 In other words, he had to find a way of translating instructions 435 00:35:27,720 --> 00:35:32,120 like these into a language that machines could understand. 436 00:35:32,120 --> 00:35:36,440 And with flawless, impeccable logic, Turing did exactly that. 437 00:35:42,520 --> 00:35:47,240 This may look like a random series of ones and zeroes, 438 00:35:47,240 --> 00:35:49,880 but to a computing machine, it's a set of instructions 439 00:35:49,880 --> 00:35:52,720 that can be read off step by step, 440 00:35:52,720 --> 00:35:56,760 telling the machine to behave in a certain way. 441 00:35:56,760 --> 00:35:59,840 So, while a human computer could look at this symbol 442 00:35:59,840 --> 00:36:02,120 and understand the process that was required, 443 00:36:02,120 --> 00:36:06,680 the computing machine had to have it explained, like this. 444 00:36:09,000 --> 00:36:12,400 This paper tape that Turing envisaged is what 445 00:36:12,400 --> 00:36:14,840 we would now call the memory of the computer. 446 00:36:16,240 --> 00:36:18,280 But Turing didn't stop there. 447 00:36:23,360 --> 00:36:27,040 Turing realised that feeding a machine instructions in this way 448 00:36:27,040 --> 00:36:29,720 had an amazing consequence. 449 00:36:29,720 --> 00:36:33,960 It meant that just one machine is needed to perform almost any task 450 00:36:33,960 --> 00:36:36,200 you can think of. 451 00:36:36,200 --> 00:36:39,160 It's a beautifully simple concept. 452 00:36:39,160 --> 00:36:42,680 In order to get the machine to do something new, all you had to do 453 00:36:42,680 --> 00:36:46,800 was feed it a new set of instructions, new information. 454 00:36:48,160 --> 00:36:52,000 This idea became known as the Universal Turing Machine. 455 00:36:56,080 --> 00:37:02,200 The more you wanted your machine to do, the longer the tape had to be. 456 00:37:02,200 --> 00:37:06,240 Bigger memories could hold complex, multilayered instructions 457 00:37:06,240 --> 00:37:11,520 about how to process and order any kind of information imaginable. 458 00:37:15,560 --> 00:37:16,760 With a big enough memory, 459 00:37:16,760 --> 00:37:21,440 the computer will be capable of an almost limitless number of tasks. 460 00:37:26,400 --> 00:37:30,600 This idea of Turing's, that a multitude of different tasks 461 00:37:30,600 --> 00:37:34,000 can be carried out simply by giving a computing machine 462 00:37:34,000 --> 00:37:38,320 a long sequence of instructions, is his greatest legacy. 463 00:37:38,320 --> 00:37:42,040 Since his paper, Turing's dream has been realised. 464 00:37:42,040 --> 00:37:45,240 So, calculations, making phone calls, 465 00:37:45,240 --> 00:37:49,360 recording moving images, writing letters, listening to music - 466 00:37:49,360 --> 00:37:52,520 none of these require bespoke machines. 467 00:37:52,520 --> 00:37:55,160 They can all be carried out on a single device. 468 00:37:56,400 --> 00:37:58,200 A computing machine. 469 00:37:59,240 --> 00:38:03,800 This phone is a modern incarnation of Turing's amazing idea. 470 00:38:03,800 --> 00:38:06,840 Inside here are many, many instructions. 471 00:38:06,840 --> 00:38:09,800 What we call programmes, or software, or apps, 472 00:38:09,800 --> 00:38:13,240 that are nothing more than a long sequence of numbers 473 00:38:13,240 --> 00:38:15,800 telling the phone what to do. 474 00:38:18,320 --> 00:38:23,600 What's amazing about Turing's idea is its incredible scope. 475 00:38:23,600 --> 00:38:26,680 The sets of instructions that can be fed to a computer 476 00:38:26,680 --> 00:38:30,840 could tell it how to mimic telephones or typewriters. 477 00:38:30,840 --> 00:38:33,760 But they could also describe the rules of nature, 478 00:38:33,760 --> 00:38:36,200 the laws of physics. 479 00:38:36,200 --> 00:38:39,040 The processes of the natural world. 480 00:38:43,520 --> 00:38:47,160 This is a simulation of many millions of particles 481 00:38:47,160 --> 00:38:49,480 behaving like a fluid. 482 00:38:49,480 --> 00:38:51,400 To work out how it flows, 483 00:38:51,400 --> 00:38:55,680 the computer simply follows a set of instructions held in its memory. 484 00:38:57,400 --> 00:39:01,200 This only begins to hint at the power of computing machines. 485 00:39:10,560 --> 00:39:14,800 This is a computer simulation of the large-scale structure 486 00:39:14,800 --> 00:39:17,600 of the entire universe. 487 00:39:17,600 --> 00:39:21,160 And it reveals the true power of Turing's idea. 488 00:39:23,320 --> 00:39:27,400 Turning instructions into symbols that a machine can understand 489 00:39:27,400 --> 00:39:32,400 allows you to recreate not just a simple picture or sound, 490 00:39:32,400 --> 00:39:37,760 but a process, a system, something that is changing and evolving. 491 00:39:40,000 --> 00:39:42,760 By manipulating simple symbols, 492 00:39:42,760 --> 00:39:46,080 computers are capable of capturing the essence, 493 00:39:46,080 --> 00:39:49,520 the order of the natural world itself. 494 00:40:03,720 --> 00:40:07,520 By thinking about how the human brain processes 495 00:40:07,520 --> 00:40:09,760 and computes information, 496 00:40:09,760 --> 00:40:13,920 Alan Turing had had one of the most important ideas of the 20th century. 497 00:40:16,800 --> 00:40:20,800 The power of information was revealing itself. 498 00:40:25,920 --> 00:40:29,440 GARBLED VOICES 499 00:40:34,840 --> 00:40:39,320 It would be very easy to think that after Turing's ideas were made real, 500 00:40:39,320 --> 00:40:43,160 the true power of information would be unleashed. 501 00:40:43,160 --> 00:40:45,640 But Turing was only half the story. 502 00:40:46,800 --> 00:40:50,400 The modern information age would require another idea, 503 00:40:50,400 --> 00:40:53,600 one that would finally pin down the nature of information, 504 00:40:53,600 --> 00:40:58,360 and its relationship to the order and disorder of the universe. 505 00:40:58,360 --> 00:41:00,640 It was an idea that would be dreamt up 506 00:41:00,640 --> 00:41:04,080 by a gifted and eccentric mathematician and engineer. 507 00:41:13,440 --> 00:41:17,280 Claude Shannon was a true maverick, and his desire to tackle 508 00:41:17,280 --> 00:41:21,760 unusual problems would lead to a revolutionary new idea. 509 00:41:21,760 --> 00:41:25,960 One that would uncover the fundamental nature of information, 510 00:41:25,960 --> 00:41:30,040 and the process of communication in all its varied forms. 511 00:41:32,520 --> 00:41:35,360 This is Claude Shannon's paper, 512 00:41:35,360 --> 00:41:38,440 The Mathematical Theory Of Communication. 513 00:41:38,440 --> 00:41:41,440 Now, the title may sound a bit dry, but trust me, 514 00:41:41,440 --> 00:41:44,080 it's one of the most important scientific papers 515 00:41:44,080 --> 00:41:47,280 of the 20th century. Not only did it lay the foundations 516 00:41:47,280 --> 00:41:50,560 for the modern world's communication network, 517 00:41:50,560 --> 00:41:54,000 it also gave us fresh insights into human language, 518 00:41:54,000 --> 00:41:58,760 into things we do intuitively, like speaking and writing. 519 00:42:04,480 --> 00:42:07,760 The paper was published in 1948, 520 00:42:07,760 --> 00:42:10,920 while Shannon was working at the Bell Labs in New Jersey - 521 00:42:10,920 --> 00:42:15,080 the research arm of the vast Bell Telephone Network. 522 00:42:15,080 --> 00:42:18,200 It was an institution famous for its forward-thinking, 523 00:42:18,200 --> 00:42:21,160 relaxed atmosphere. 524 00:42:21,160 --> 00:42:26,400 The mathematicians were free to work on any problem that interested them. 525 00:42:26,400 --> 00:42:32,040 The only thing that the laboratory management required of them 526 00:42:32,040 --> 00:42:33,880 was that they keep an open door, 527 00:42:33,880 --> 00:42:38,240 and if anybody from any other department came with a problem, 528 00:42:38,240 --> 00:42:41,080 that they would at least think about it. 529 00:42:41,080 --> 00:42:46,680 Otherwise they were absolutely free, and the atmosphere was incredible. 530 00:42:46,680 --> 00:42:49,920 People were playing, and encouraged to play. 531 00:42:51,480 --> 00:42:53,200 Hello. I'm Claude Shannon, 532 00:42:53,200 --> 00:42:56,200 a mathematician here at the Bell Telephone Laboratory. 533 00:42:56,200 --> 00:42:59,480 Claude Shannon in particular was given free reign 534 00:42:59,480 --> 00:43:01,600 to do pretty much whatever he wanted. 535 00:43:01,600 --> 00:43:03,120 This is Theseus. 536 00:43:03,120 --> 00:43:05,760 Theseus is an electrically controlled mouse, mouse. 537 00:43:08,000 --> 00:43:10,240 Oh, they treated him as their darling. 538 00:43:10,240 --> 00:43:15,080 I never saw him juggle, but I certainly saw him ride his unicycle. 539 00:43:15,080 --> 00:43:16,920 He brought it to work one day, 540 00:43:16,920 --> 00:43:21,080 and he must have cost Bell Labs 541 00:43:21,080 --> 00:43:24,640 at least a hundred man-hours of time. 542 00:43:29,320 --> 00:43:31,360 But despite the frivolity, 543 00:43:31,360 --> 00:43:34,920 the Bell Telephone Network faced a huge problem. 544 00:43:34,920 --> 00:43:38,040 Every day, they transmitted vast amounts of electronic 545 00:43:38,040 --> 00:43:40,920 information all across the world. 546 00:43:40,920 --> 00:43:45,160 But they had no real idea of how to measure this information properly, 547 00:43:45,160 --> 00:43:47,320 or how to quantify it. 548 00:43:50,000 --> 00:43:53,280 In short, their entire business was built on something 549 00:43:53,280 --> 00:43:55,160 they didn't actually understand. 550 00:43:57,600 --> 00:44:01,200 Amazingly, their superstar employee Claude Shannon 551 00:44:01,200 --> 00:44:04,440 would give them exactly what they needed. 552 00:44:04,440 --> 00:44:07,920 GARBLED VOICES 553 00:44:11,800 --> 00:44:16,360 In this paper, Shannon did something absolutely incredible - 554 00:44:16,360 --> 00:44:20,480 he took the vague and mysterious concept of information 555 00:44:20,480 --> 00:44:22,640 and managed to pin it down. 556 00:44:22,640 --> 00:44:25,120 Now, he didn't do this using some cleverly-worded, 557 00:44:25,120 --> 00:44:27,200 philosophical definition. 558 00:44:27,200 --> 00:44:29,320 He actually found a way to measure 559 00:44:29,320 --> 00:44:32,040 the information contained in a message. 560 00:44:32,040 --> 00:44:34,960 GARBLED VOICES 561 00:44:37,160 --> 00:44:40,240 Amazingly, Shannon realised that the quantity of information 562 00:44:40,240 --> 00:44:42,640 in a message had nothing to do with its meaning. 563 00:44:44,080 --> 00:44:46,080 Instead, he showed it was related solely 564 00:44:46,080 --> 00:44:48,200 to how unusual the message was. 565 00:44:52,560 --> 00:44:55,720 Information is related to unexpectedness. 566 00:44:55,720 --> 00:44:58,120 So news is news because it's unexpected 567 00:44:58,120 --> 00:45:01,280 and the more unexpected it is, the more newsworthy it is. 568 00:45:01,280 --> 00:45:03,560 So if today's news was the same as yesterday's news, 569 00:45:03,560 --> 00:45:05,200 there would be no news at all. 570 00:45:05,200 --> 00:45:08,200 And that information content would be zero. 571 00:45:08,200 --> 00:45:11,080 So suddenly you have a relationship between... 572 00:45:11,080 --> 00:45:16,160 unexpectedness and information. 573 00:45:16,160 --> 00:45:19,520 GARBLED VOICES 574 00:45:19,520 --> 00:45:21,440 But Shannon was to go further 575 00:45:21,440 --> 00:45:24,880 and give information its very own unit of measurement. 576 00:45:26,120 --> 00:45:28,960 GARBLED VOICES 577 00:45:31,080 --> 00:45:34,040 So, how did he do this? 578 00:45:34,040 --> 00:45:37,480 Well, he showed that any message you cared to send 579 00:45:37,480 --> 00:45:40,360 could be translated into binary digits - 580 00:45:40,360 --> 00:45:43,600 a long sequence of ones and zeros. 581 00:45:43,600 --> 00:45:48,680 So a simple greeting like "Hello" could be written like this. 582 00:45:50,160 --> 00:45:52,880 Or...like this. 583 00:45:52,880 --> 00:45:58,200 Just think of this as another way of writing the same message. 584 00:45:59,480 --> 00:46:02,400 ELECTRONIC MUSIC 585 00:46:04,480 --> 00:46:08,760 Shannon realised that transforming information into binary digits 586 00:46:08,760 --> 00:46:11,160 would be an immensely powerful act. 587 00:46:11,160 --> 00:46:13,440 It would make information 588 00:46:13,440 --> 00:46:17,480 manageable, exact, controllable and precise. 589 00:46:21,000 --> 00:46:25,200 In his paper, Shannon showed that a single binary digit - 590 00:46:25,200 --> 00:46:30,720 one of these ones or zeros - is a fundamental unit of information. 591 00:46:30,720 --> 00:46:33,520 Think of it as an atom of information - 592 00:46:33,520 --> 00:46:36,400 the smallest possible piece. 593 00:46:36,400 --> 00:46:38,840 Then, having defined this basic unit, 594 00:46:38,840 --> 00:46:42,880 he even gave us a name for it, one we're all familiar with today. 595 00:46:42,880 --> 00:46:47,560 He used a shortening of the phrase, "binary digit" - 596 00:46:47,560 --> 00:46:49,200 "bit". 597 00:46:49,200 --> 00:46:53,880 The humble bit turned out to be an enormously powerful idea. 598 00:46:57,200 --> 00:47:00,560 The bit is the smallest quantity of information. 599 00:47:00,560 --> 00:47:03,680 It is highly significant because it's the fundamental atom. 600 00:47:03,680 --> 00:47:06,720 It is the smallest unit of information in which 601 00:47:06,720 --> 00:47:10,520 there's sufficient discrimination to communicate anything at all. 602 00:47:15,600 --> 00:47:19,200 The power of the bit lay in its universality. 603 00:47:20,840 --> 00:47:23,320 Any system that has two states, 604 00:47:23,320 --> 00:47:25,840 like a coin with heads or tails, 605 00:47:25,840 --> 00:47:28,800 can carry one bit of information. 606 00:47:30,600 --> 00:47:32,640 One or zero. 607 00:47:32,640 --> 00:47:34,680 Punched or not punched. 608 00:47:34,680 --> 00:47:36,520 On or off. 609 00:47:36,520 --> 00:47:38,320 Stop or go. 610 00:47:38,320 --> 00:47:43,160 All of these systems can store one bit of information. 611 00:47:46,080 --> 00:47:47,480 Thanks to Shannon, 612 00:47:47,480 --> 00:47:52,360 the bit became the common language of all information. 613 00:47:52,360 --> 00:47:57,520 Anything - sounds, pictures, text - can be turned into bits 614 00:47:57,520 --> 00:48:02,720 and transmitted by any system capable of being in just two states. 615 00:48:11,200 --> 00:48:15,520 Shannon had founded a new, far-reaching theory. 616 00:48:15,520 --> 00:48:18,880 The ideas he began to explore would form the cornerstone 617 00:48:18,880 --> 00:48:21,600 of what we now call, "information theory". 618 00:48:21,600 --> 00:48:25,240 He'd taken an abstract concept - information - 619 00:48:25,240 --> 00:48:27,880 and turned it into something tangible. 620 00:48:27,880 --> 00:48:31,520 What had been just a vague notion 621 00:48:31,520 --> 00:48:35,480 was now measurable - something real. 622 00:48:40,400 --> 00:48:44,480 The idea of converting into bits, into making things digital, 623 00:48:44,480 --> 00:48:48,480 would fundamentally transform many aspects of human society. 624 00:48:49,720 --> 00:48:52,680 GARBLED VOICES 625 00:48:56,880 --> 00:49:01,080 But information isn't just something humans create. 626 00:49:01,080 --> 00:49:04,280 We're beginning to understand that this concept lies at the heart, 627 00:49:04,280 --> 00:49:07,920 not only of 21st-century human society, 628 00:49:07,920 --> 00:49:11,080 but also at the heart of the physical world itself. 629 00:49:11,080 --> 00:49:16,840 Every "bit" of information we've ever created, every book, 630 00:49:16,840 --> 00:49:21,760 every film, the entire contents of the internet, 631 00:49:21,760 --> 00:49:23,800 amounts to pretty much nothing 632 00:49:23,800 --> 00:49:26,800 when compared with the information content of nature. 633 00:49:26,800 --> 00:49:30,880 And that's because even the most insignificant event 634 00:49:30,880 --> 00:49:33,920 contains a spectacular amount of information. 635 00:49:33,920 --> 00:49:35,560 Let me show you. 636 00:49:49,680 --> 00:49:55,040 Imagine how many bits of information you would need to describe this. 637 00:50:02,040 --> 00:50:05,800 The beautiful and intricate interplay of physical laws 638 00:50:05,800 --> 00:50:08,640 taking place at scales and timeframes 639 00:50:08,640 --> 00:50:11,640 that are normally imperceptible to us. 640 00:50:17,480 --> 00:50:20,240 But here you're still only seeing a fraction 641 00:50:20,240 --> 00:50:22,360 of the complexity of nature. 642 00:50:41,160 --> 00:50:46,840 Imagine the interplay between the trillions upon trillions of atoms. 643 00:50:49,240 --> 00:50:52,040 The amount of bits you would need to describe this 644 00:50:52,040 --> 00:50:53,680 is almost unimaginable. 645 00:50:58,000 --> 00:51:00,600 But what's amazing is that now, 646 00:51:00,600 --> 00:51:05,520 thanks to the ideas of Turing and Shannon, we're able to describe, 647 00:51:05,520 --> 00:51:09,120 model and simulate nature in ever greater detail. 648 00:51:11,600 --> 00:51:15,120 But this isn't the end of the story. 649 00:51:15,120 --> 00:51:20,560 Information, it seems, isn't just a way of describing reality. 650 00:51:22,520 --> 00:51:25,760 In the last few years, we've discovered that information 651 00:51:25,760 --> 00:51:29,280 is actually an inseparable part of the physical world. 652 00:51:43,240 --> 00:51:48,840 It's a really difficult idea to get to grips with but information, 653 00:51:48,840 --> 00:51:53,480 everything from a Beethoven symphony to the contents of a dictionary, 654 00:51:53,480 --> 00:51:55,080 even a fleeting thought, 655 00:51:55,080 --> 00:52:00,320 all information needs to be embodied in some form of physical system. 656 00:52:02,840 --> 00:52:06,960 Amazingly, the reason we understand the true connection 657 00:52:06,960 --> 00:52:12,160 between information and reality is because of Maxwell's demon. 658 00:52:14,840 --> 00:52:19,040 Remember, it seemed like the demon could use information 659 00:52:19,040 --> 00:52:24,680 to create order in a box of air that started out completely disordered. 660 00:52:24,680 --> 00:52:28,000 Moreover, it could do this without expending any effort. 661 00:52:30,000 --> 00:52:33,320 Information seemed to be able to break the laws of physics. 662 00:52:34,720 --> 00:52:38,000 Well, that's not true - it can't. 663 00:52:44,240 --> 00:52:49,320 The reason why Maxwell's demon can't get energy for free lies here - 664 00:52:49,320 --> 00:52:51,080 in his head. 665 00:52:57,240 --> 00:52:59,280 What was discovered was this - 666 00:52:59,280 --> 00:53:02,520 the demon really is using nothing more than information 667 00:53:02,520 --> 00:53:04,560 to create useful energy. 668 00:53:04,560 --> 00:53:07,800 But this doesn't mean that he's getting something for nothing. 669 00:53:07,800 --> 00:53:10,480 Remember how the demon works? 670 00:53:10,480 --> 00:53:14,480 He spots a fast-moving molecule on one side of the box, 671 00:53:14,480 --> 00:53:17,560 opens a partition and lets it through to the other side. 672 00:53:17,560 --> 00:53:21,680 But each time he does that, he has to store information 673 00:53:21,680 --> 00:53:25,080 about that molecule's speed in his memory. 674 00:53:26,520 --> 00:53:30,760 Soon his memory will fill up and then he can only continue 675 00:53:30,760 --> 00:53:33,800 if he starts deleting information. 676 00:53:33,800 --> 00:53:38,480 Crucially this deletion would require him to expend energy. 677 00:53:39,920 --> 00:53:44,840 The demon needs to keep a record of which molecules are moving where 678 00:53:44,840 --> 00:53:48,840 and if the record-keeping device is only finite size, 679 00:53:48,840 --> 00:53:51,280 at some point the demon is going to have to erase it. 680 00:53:51,280 --> 00:53:53,120 That's an irreversible process 681 00:53:53,120 --> 00:53:55,600 that increases the entropy of the universe. 682 00:53:55,600 --> 00:53:57,720 Its the erasure of information 683 00:53:57,720 --> 00:53:59,800 that increases entropy once and for all. 684 00:54:02,840 --> 00:54:04,440 What was discovered 685 00:54:04,440 --> 00:54:07,920 is that there's a certain, specific minimum amount of energy, 686 00:54:07,920 --> 00:54:10,080 known as the Landauer limit, 687 00:54:10,080 --> 00:54:14,200 that's required to delete one bit of information. 688 00:54:15,640 --> 00:54:20,520 It's tiny, less than a trillion trillionth of the amount of energy 689 00:54:20,520 --> 00:54:23,720 in a gram of sugar, but it's real. 690 00:54:23,720 --> 00:54:27,400 It's a part of the fundamental fabric of the universe. 691 00:54:34,760 --> 00:54:38,600 Amazingly, we can now do real experiments 692 00:54:38,600 --> 00:54:40,720 that test aspects of Maxwell's idea. 693 00:54:41,840 --> 00:54:45,960 By using lasers and tiny particles of dust, 694 00:54:45,960 --> 00:54:48,560 scientists around the world have explored the relationship 695 00:54:48,560 --> 00:54:53,160 between information and energy with incredible accuracy. 696 00:54:54,960 --> 00:54:59,120 Maxwell's thought experiment, dreamt up in the age of steam, 697 00:54:59,120 --> 00:55:03,080 still remains at the cutting edge of scientific research today. 698 00:55:08,760 --> 00:55:13,200 Maxwell's demon links together two of the most important concepts 699 00:55:13,200 --> 00:55:17,480 in science - the study of energy and the study of information 700 00:55:17,480 --> 00:55:21,240 and shows that the two are profoundly linked. 701 00:55:21,240 --> 00:55:23,720 What we now know is that information, 702 00:55:23,720 --> 00:55:26,520 far from being some abstract concept, 703 00:55:26,520 --> 00:55:30,600 obeys the same laws of physics as everything else in the universe. 704 00:55:39,360 --> 00:55:42,640 Information is not just an abstraction, 705 00:55:42,640 --> 00:55:46,440 just a mathematical thing or formula that you write on the paper. 706 00:55:46,440 --> 00:55:48,880 Information is actually carried by something. 707 00:55:48,880 --> 00:55:51,520 So it is encoded onto something - 708 00:55:51,520 --> 00:55:55,000 a stone, a book, a CD. 709 00:55:55,000 --> 00:55:58,040 Whatever it is, there is a carrier where the information is on. 710 00:55:58,040 --> 00:56:02,800 That means that information behaves according to those laws of physics. 711 00:56:02,800 --> 00:56:05,520 So it cannot break the laws of physics. 712 00:56:11,240 --> 00:56:15,320 What humanity has learnt over the last few millennia 713 00:56:15,320 --> 00:56:19,480 is that information can never be divorced from the physical world. 714 00:56:25,280 --> 00:56:26,960 But this is not a hindrance. 715 00:56:26,960 --> 00:56:32,160 What makes information so powerful is the fact it can be stored 716 00:56:32,160 --> 00:56:35,400 in any physical system we choose. 717 00:56:36,800 --> 00:56:39,920 From using stone and clay to allow information 718 00:56:39,920 --> 00:56:42,360 to be preserved over eons 719 00:56:42,360 --> 00:56:46,440 to using electricity and light so it can be sent quickly, 720 00:56:46,440 --> 00:56:51,040 the medium that stores information gives it unique properties. 721 00:56:55,720 --> 00:56:59,840 Today, scientists are exploring new ways of manipulating information, 722 00:56:59,840 --> 00:57:04,440 using everything from DNA to quantum particles. 723 00:57:04,440 --> 00:57:08,720 They hope that this work will usher in a new information age, 724 00:57:08,720 --> 00:57:11,960 every bit as transformative as the last. 725 00:57:14,800 --> 00:57:18,880 What we now know is that we are just at the beginning of our journey 726 00:57:18,880 --> 00:57:21,840 to unlock the power of information. 727 00:57:38,040 --> 00:57:41,480 It's always been clear that creating physical order - 728 00:57:41,480 --> 00:57:44,760 the structures we see around us - has a cost. 729 00:57:44,760 --> 00:57:48,920 We need to do work to expend energy to build them. 730 00:57:48,920 --> 00:57:52,720 But in the last few years, we've learnt that ordering information, 731 00:57:52,720 --> 00:57:56,840 creating the invisible, digital structures of the modern world, 732 00:57:56,840 --> 00:57:59,480 also has an inescapable cost. 733 00:57:59,480 --> 00:58:03,200 As abstract and ethereal as information seems, 734 00:58:03,200 --> 00:58:07,200 we now know it must always be embodied in a physical system. 735 00:58:07,200 --> 00:58:10,680 I find this an incredibly exciting idea. 736 00:58:10,680 --> 00:58:15,960 Think about it this way - a lump of clay can be used to write a poem on. 737 00:58:15,960 --> 00:58:20,240 Molecules of air can carry the sound of a symphony. 738 00:58:20,240 --> 00:58:24,080 And a single photon is like a paint brush. 739 00:58:24,080 --> 00:58:26,480 Every aspect of the physical universe 740 00:58:26,480 --> 00:58:28,880 can be thought of as a blank canvas, 741 00:58:28,880 --> 00:58:33,720 which we can use to build beauty, structure and order. 742 00:58:47,280 --> 00:58:52,840 Subtitles By Red Bee Media Ltd