1 00:00:00,000 --> 00:00:04,040 They used to meet in secret to discuss their mathematical discoveries. 2 00:00:05,040 --> 00:00:07,460 Only members were allowed to attend. 3 00:00:08,160 --> 00:00:11,180 They had a secret emblem, the pentagram. 4 00:00:15,500 --> 00:00:18,040 Let's see what the topic is for today. 5 00:00:30,000 --> 00:00:56,840 It was our old friend Pythagoras who discovered that the pentagram was full of mathemagic. 6 00:01:00,000 --> 00:01:04,780 The two shorter lines combined exactly equal the third. 7 00:01:05,480 --> 00:01:09,400 And this line shows the magic proportions of the famous golden section. 8 00:01:10,440 --> 00:01:14,160 The second and third lines exactly equal the fourth. 9 00:01:14,660 --> 00:01:16,420 Once again we have the golden section. 10 00:01:18,440 --> 00:01:20,240 But this is only the beginning. 11 00:01:21,220 --> 00:01:25,860 Hidden within the pentagram is a secret for creating a golden rectangle 12 00:01:25,860 --> 00:01:30,660 which the Greeks admired for its beautiful proportions and magic qualities. 13 00:01:31,340 --> 00:01:35,300 The star contains the golden rectangle many times over. 14 00:01:35,300 --> 00:02:04,760 It's a most remarkable shape. 15 00:02:04,760 --> 00:02:08,480 It can mathematically reproduce itself indefinitely. 16 00:02:13,360 --> 00:02:17,400 All these rectangles have exactly the same proportions. 17 00:02:24,480 --> 00:02:27,820 This figure also contains a magic spiral 18 00:02:27,820 --> 00:02:32,500 that repeats the proportions of the golden section into infinity. 19 00:02:32,500 --> 00:02:38,440 To the Greeks, the golden rectangle represented a mathematical law of beauty. 20 00:02:39,520 --> 00:02:41,780 We find it in their classical architecture. 21 00:02:43,020 --> 00:02:46,860 The Parthenon, perhaps one of the most famous of early Greek buildings, 22 00:02:47,220 --> 00:02:48,500 contains many golden rectangles. 23 00:02:48,500 --> 00:02:49,500 These same golden proportions are also found in their sculpture. 24 00:02:49,500 --> 00:03:07,500 These same golden proportions are also found in their sculpture. 25 00:03:07,500 --> 00:03:14,500 These same golden proportions are also found in their sculpture. 26 00:03:14,500 --> 00:03:33,500 In the centuries that followed, the golden rectangle dominated the idea of beauty and architecture throughout the Western world. 27 00:03:33,500 --> 00:03:40,500 The cathedral of Notre Dame is an outstanding example. 28 00:03:40,500 --> 00:03:43,940 The cathedral of Notre Dame is an outstanding example. 29 00:03:43,940 --> 00:03:50,940 The Renaissance painters knew this secret well. 30 00:03:50,940 --> 00:03:56,080 Think of a pentagram, Donald. 31 00:03:56,080 --> 00:04:03,080 Now put another inside, a third and a fourth. 32 00:04:03,080 --> 00:04:07,080 No pencil is sharp enough to draw as fine as you can think. 33 00:04:07,080 --> 00:04:08,080 Think. 34 00:04:08,080 --> 00:04:11,080 And no paper large enough to hold your imagination. 35 00:04:11,080 --> 00:04:16,080 In fact, it is only in the mind that we can conceive infinity. 36 00:04:16,080 --> 00:04:22,080 Mathematical thinking has opened the doors to the exciting adventures of science. 37 00:04:22,080 --> 00:04:29,080 I've never seen so many doors before. 38 00:04:29,080 --> 00:04:32,080 Each discovery leads to many others. 39 00:04:32,080 --> 00:04:34,080 An endless chain. 40 00:04:34,080 --> 00:04:38,080 What's the matter with these doors? 41 00:04:38,080 --> 00:04:39,080 Hey! 42 00:04:39,080 --> 00:04:40,080 These doors won't open. 43 00:04:40,080 --> 00:04:41,080 Get out! 44 00:04:42,080 --> 00:04:44,080 Of course they are locked. 45 00:04:44,080 --> 00:04:46,080 These are the doors of the future. 46 00:04:46,080 --> 00:04:47,080 And the key is... 47 00:04:47,080 --> 00:04:49,080 Mathematics! 48 00:04:49,080 --> 00:04:50,080 Right. 49 00:04:50,080 --> 00:04:51,080 Mathematics! 50 00:04:51,080 --> 00:04:56,080 The boundless treasures of science are locked behind those doors. 51 00:04:56,080 --> 00:05:02,080 In time, they will be opened by the curious and inquiring minds of future generations.