1 00:00:11,177 --> 00:00:12,701 Where do we come from? 2 00:00:14,014 --> 00:00:15,777 How did the universe begin? 3 00:00:19,652 --> 00:00:21,950 Why... is the universe the way it is? 4 00:00:25,625 --> 00:00:27,320 Morning welcome to Gonville and Caius 5 00:00:27,627 --> 00:00:29,288 More commonly known as Caius College 6 00:00:31,431 --> 00:00:36,164 Caius College was founded in 1348... by Edmund Gonville 7 00:00:36,870 --> 00:00:38,269 Where are we going? 8 00:00:40,607 --> 00:00:43,041 Here we come to the portrait of probably our most famous Caian 9 00:00:43,510 --> 00:00:46,638 Professor Stephen Hawking, the world famous cosmologist 10 00:00:52,118 --> 00:00:54,245 And Iike his predecessor Sir lsaac Newton before him 11 00:00:54,354 --> 00:00:57,152 He is Iucasian professor of mathematics for the university 12 00:00:57,891 --> 00:01:00,985 And his particular sphere is research of the black hole 13 00:01:01,127 --> 00:01:03,994 and the history of the universe culminating in his book 14 00:01:04,130 --> 00:01:07,327 The Brief History of Time which worldwide has sold over eight million copies 15 00:01:08,168 --> 00:01:10,693 All of my life I have been fascinated... 16 00:01:10,804 --> 00:01:13,364 By the big questions that face us, 17 00:01:13,540 --> 00:01:16,998 and have tried to find scientific answers to them 18 00:01:17,444 --> 00:01:19,139 Perhaps that's why I have sold... 19 00:01:19,245 --> 00:01:23,375 more books on physics than Madonna has on sex 20 00:01:27,454 --> 00:01:28,284 This is Professor Hawking's... 21 00:01:28,388 --> 00:01:30,856 study, which he will use when he's in residence in college 22 00:01:32,092 --> 00:01:34,253 Who he'd use for his tutorials or meetings or any... 23 00:01:34,360 --> 00:01:35,850 private work he needs to do 24 00:01:41,734 --> 00:01:43,531 It's very much personal room with his books... 25 00:01:43,636 --> 00:01:46,503 and his portraits and pictures. So it's really home from home... 26 00:01:46,606 --> 00:01:47,664 when their in college 27 00:01:50,043 --> 00:01:52,511 He's got in herited disease motor neurone disease 28 00:01:52,712 --> 00:01:54,339 He can project his voice with a synthesiser 29 00:01:54,447 --> 00:01:56,278 Which is attached to his wheel chair 30 00:02:02,021 --> 00:02:04,819 I hope you enjoyed your visit. Bye, bye 31 00:02:06,259 --> 00:02:12,562 If like me you have looked at the stars and tried to make sense of what you see, 32 00:02:12,732 --> 00:02:16,691 you too have started to wonder what makes the universe exist 33 00:02:17,704 --> 00:02:21,196 The questions are clear and deceptively simple 34 00:02:21,875 --> 00:02:28,178 But the answers have always seemed wel I beyond our reach, until now 35 00:03:00,813 --> 00:03:05,477 For thousands of years our view of the universe changed very little 36 00:03:06,553 --> 00:03:10,250 But the discoveries of scientists from Gallilleo to Einstein 37 00:03:10,423 --> 00:03:14,553 over the past four hundred years have advanced our understanding 38 00:03:14,761 --> 00:03:19,824 at an ever increasing rate- and revolution ised the way we think 39 00:03:22,368 --> 00:03:24,996 Further breakthroughs over the last few decades 40 00:03:25,238 --> 00:03:29,504 have brought us closer than ever to secrets of the cosmos 41 00:03:36,816 --> 00:03:40,877 These dramatic scientific discoveries reveal a universe full of 42 00:03:40,987 --> 00:03:44,889 strange sounding ideas and remarkable images; 43 00:03:45,525 --> 00:03:53,762 the Big Bang-black holes-invisible or dark matter-and a possible big crunch 44 00:03:57,804 --> 00:04:01,296 The story of how we arrived at th is picture is the story of 45 00:04:01,407 --> 00:04:04,604 Iearning to understand what we see 46 00:04:30,536 --> 00:04:34,734 Eighty years ago at the Mount Wi lson Observatory i n Cal iforn ia, 47 00:04:34,974 --> 00:04:39,240 a you ng astronomer looked th roug h the h u nd red i nch telescope deep i nto space 48 00:04:40,246 --> 00:04:45,548 What Edwi n H u bble saw revol ution ised ou r view of ou r place i n the u n iverse 49 00:04:51,624 --> 00:04:53,649 Er, we know than ks to H u bble, that... 50 00:04:53,793 --> 00:04:56,785 that altogether with i n the I i m its of the observable u n iverse 51 00:04:56,896 --> 00:05:01,492 there's someth i ng I i ke one h u nd red bi I l ion tri I l ion stars, it's a lot of stars 52 00:05:01,768 --> 00:05:04,293 And we now know than ks to recent d iscoveries, 53 00:05:04,404 --> 00:05:08,101 very recent d iscoveries also er what we had bel ieved 54 00:05:08,207 --> 00:05:12,371 but had no proof of is that many of those stars have planets 55 00:05:12,879 --> 00:05:16,110 So there are cou ntless tri I l ions of planets i n the observable u n iverse 56 00:05:21,187 --> 00:05:24,588 T oday we see deeper i nto the u n iverse than ever before, 57 00:05:24,857 --> 00:05:28,088 than ks to the space telescope named after Edwi n H u bble 58 00:05:28,628 --> 00:05:33,497 The more we see, the less special ou r place i n the u n iverse seems 59 00:05:34,934 --> 00:05:37,801 Two th i rds of the stars and planets and I ife, 60 00:05:37,937 --> 00:05:41,930 if it's there, i n the u n iverse are bi I l ions of years older than we are 61 00:05:42,141 --> 00:05:45,907 And if you ask what a bi I l ion years means er i n the h istory of I ife, 62 00:05:46,012 --> 00:05:47,843 I must tell you that a billion years ago 63 00:05:47,947 --> 00:05:50,245 the highest form of life on the earth was a worm, 64 00:05:50,416 --> 00:05:53,613 three billion yeas ago the highest form of life on the earth were bacteria 65 00:05:57,256 --> 00:06:01,693 So we m ust ask ou rselves we who are so proud of ou r accom pl ish ments er 66 00:06:01,794 --> 00:06:04,354 what is ou r place i n the cosm ic perspective of I ife 67 00:06:04,630 --> 00:06:07,428 if most of those bei ngs out there, if they are there, 68 00:06:07,600 --> 00:06:11,036 are stand i n relationsh i p to us as we do to the worms on th is planet 69 00:06:11,270 --> 00:06:13,864 and that is not meant to be a den ig rati ng remark 70 00:06:14,040 --> 00:06:18,875 but on ly to suggest that h u man ki nd's g reatest experiences sti I l I ie ahead of us 71 00:06:22,915 --> 00:06:24,940 T oday's scientific approach to u nderstand i ng 72 00:06:25,051 --> 00:06:28,885 the u n iverse real ly began about 3,000 years ago 73 00:06:30,456 --> 00:06:34,586 Before than people based thei r ideas on myths and legends 74 00:06:37,497 --> 00:06:41,831 They cou ld see the stars and wonder about the sky and the heavens, but er... 75 00:06:41,934 --> 00:06:46,428 they had very I ittle i nformation i ndeed, j ust what thei r eyes cou ld pick u p 76 00:06:53,479 --> 00:06:56,744 They thought that everything they knew came out of... 77 00:06:56,849 --> 00:07:01,115 the water. Obviously water was very i m portant... 78 00:07:01,220 --> 00:07:05,554 su bstance, so that they gave water a sort of cosm ic sig n ificance 79 00:07:07,360 --> 00:07:10,591 They thoug ht the heavens are made of many holes 80 00:07:10,696 --> 00:07:16,657 and these holes represent the stars and just behind they had this divine fire 81 00:07:22,308 --> 00:07:23,935 But then Greek philosophers like... 82 00:07:24,043 --> 00:07:29,606 Pythagoras on the island of Samos, saw the universe in a totally new way 83 00:07:31,784 --> 00:07:33,251 They thought they er had er... 84 00:07:33,352 --> 00:07:40,155 to find a more accurate way of expressi ng thei r views about the u n iverse, 85 00:07:40,393 --> 00:07:45,456 and er that way d ramatical ly tu rned out to be mathematics 86 00:07:48,100 --> 00:07:52,400 Usi ng mathematics the Greeks began to question ancient beliefs 87 00:07:53,172 --> 00:07:57,632 T o prove that the earth was not flat a g reek ph i losopher cal led Eratosthenes 88 00:07:57,743 --> 00:08:02,646 devised an experi ment. The scientific method was born 89 00:08:04,183 --> 00:08:07,118 He real ised that identical objects on a flat earth 90 00:08:07,286 --> 00:08:11,052 shou ld always cast identical shadows. So,... 91 00:08:11,190 --> 00:08:14,250 at the same ti me of day, i n two places, many m i les apart, 92 00:08:14,427 --> 00:08:16,486 he put th is to the test 93 00:08:18,064 --> 00:08:24,230 It was a beautifu I way er that he d iscovered where he used two sticks 94 00:08:29,709 --> 00:08:32,837 He noticed that the rays com i ng from the su n... 95 00:08:33,846 --> 00:08:36,371 prod uced d ifferent amou nts of shade... 96 00:08:36,682 --> 00:08:38,149 i n each of the two sticks 97 00:08:39,652 --> 00:08:42,815 Si nce the two sticks cast shadows of d ifferent lengths... 98 00:08:43,122 --> 00:08:45,613 the earth's su rface had to be cu rved 99 00:08:48,394 --> 00:08:50,988 And from the ang le of the shadows, Eratosthenes... 100 00:08:51,097 --> 00:08:56,194 esti mated the earth's ci rcu mference. At twenty five thousand m i les 101 00:08:56,369 --> 00:08:58,997 he was less than a h u nd red m i les out 102 00:09:01,107 --> 00:09:05,066 Mathematics had beg u n to reveal the u n iverse as we see it today 103 00:09:05,611 --> 00:09:08,808 The earth was not flat, it was rou nd 104 00:09:11,951 --> 00:09:15,318 T oday's scientists also rely on mathematics 105 00:09:15,821 --> 00:09:21,157 Ei nstei n's eq uations for g ravity pred ict what are cal led black holes 106 00:09:21,627 --> 00:09:26,587 A black hole is a gaping void in space that sucks in and devours 107 00:09:26,766 --> 00:09:28,927 anything that gets too near 108 00:09:30,570 --> 00:09:34,097 It becomes com pact, massive and therefore able, 109 00:09:34,206 --> 00:09:37,972 if it encounters someth i ng else, able to eat some more matter 110 00:09:38,077 --> 00:09:40,944 It becomes the eater of al I th i ngs 111 00:09:41,948 --> 00:09:47,909 But mathematical ly beautifu I theories are not always supported by observation 112 00:09:48,554 --> 00:09:50,954 I n the earl iest days of astronomy, 113 00:09:51,157 --> 00:09:56,288 the ancient G reeks fou nd the heavens less perfect than they had fi rst i mag i ned 114 00:09:57,430 --> 00:09:59,898 Looki ng at the skies more closely, 115 00:10:00,132 --> 00:10:04,762 they began to see stars move in a way which defied their logic 116 00:10:06,238 --> 00:10:15,271 If every n ig ht you go out and you have a carefu I look er seei ng towards south, 117 00:10:15,448 --> 00:10:21,114 after two or th ree days if you watch agai n you' I l see five stars 118 00:10:21,387 --> 00:10:29,089 They look as movi ng from west towards the east someti mes 119 00:10:29,195 --> 00:10:32,289 they look stayi ng sti I l 120 00:10:32,565 --> 00:10:38,697 then they beg i n to move more er from the east towards the west... 121 00:10:39,505 --> 00:10:45,501 and th is is someth i ng u n usual i n respect to the other stars of the sky 122 00:10:45,611 --> 00:10:48,375 wh ich don't change any position 123 00:10:49,281 --> 00:10:53,513 They gave these wanderi ng stars a name: planetos 124 00:10:54,020 --> 00:10:57,046 They were seei ng the five nearest planets 125 00:11:05,398 --> 00:11:06,797 The G reeks were convi nced the planets 126 00:11:06,899 --> 00:11:11,233 had to be perfect spheres orbiti ng i n perfect ci rcu lar motion 127 00:11:11,771 --> 00:11:14,535 But that did not fit with their observations 128 00:11:17,877 --> 00:11:22,507 The astronomer Ptolemy finally found a way to explain what they saw 129 00:11:26,686 --> 00:11:30,782 he added tiny circular adjustments to circular planetary orbits 130 00:11:30,923 --> 00:11:31,981 and put everyth i ng i nside a... 131 00:11:32,091 --> 00:11:36,050 sphere of fixed stars, with the earth at the centre 132 00:11:39,832 --> 00:11:43,233 Ptolemy I ived over a centu ry after the death of Ch rist 133 00:11:43,903 --> 00:11:46,235 The newly formed Christian church taught that 134 00:11:46,338 --> 00:11:49,967 we on earth were the centre of God's creation 135 00:11:54,046 --> 00:12:00,315 The cosmology of er the ch u rch is the cosmology of the Genesis 136 00:12:00,720 --> 00:12:10,254 and er if someth i ng er has the same ideas as they are descri bed i n Genesis it's okay 137 00:12:15,968 --> 00:12:20,962 For those who cou ld u nderstand the mathematics of Ptolemy's model, 138 00:12:21,140 --> 00:12:26,237 wel I it's a model wh ich can foretel I the position of the planets 139 00:12:26,345 --> 00:12:30,111 with any accuracy which is satisfying 140 00:12:31,417 --> 00:12:33,681 And er on the other hand 141 00:12:33,786 --> 00:12:40,589 there is nothing which can contradict the idea of the Genesis 142 00:12:45,831 --> 00:12:49,562 Th ree, two, one, zero... 143 00:12:50,703 --> 00:12:52,000 Lift off 144 00:12:52,271 --> 00:12:57,903 T oday the clai ms of the scri ptu res are bei ng put to test by experi ments... 145 00:12:58,010 --> 00:13:03,471 Iau nched i nto the heavens. The COBE satel I ite was able... 146 00:13:03,582 --> 00:13:05,072 probe deep i nto space, 147 00:13:05,184 --> 00:13:06,481 and back i n ti me, 148 00:13:06,619 --> 00:13:10,953 to detect what ou r u n iverse was I i ke d u ri ng its earl iest moments 149 00:13:11,891 --> 00:13:13,620 If you' re rel ig ious it's I i ke you know 150 00:13:13,726 --> 00:13:16,524 you' re you' re seei ng the handwriti ng of God 151 00:13:16,629 --> 00:13:18,460 when he wrote out how he was goi ng to make the u n iverse 152 00:13:19,298 --> 00:13:21,129 Here's how the u n iverse is put together rig ht, 153 00:13:21,233 --> 00:13:23,428 j ust you know read between the I i nes 154 00:13:23,536 --> 00:13:26,130 and you' I l and you' I l know the rest of you for maki ng the u n iverse 155 00:13:29,275 --> 00:13:31,835 Steady i m provements i n tech nology over the... 156 00:13:31,944 --> 00:13:36,779 years have enabled us to test ou r theories about the u n iverse 157 00:13:37,683 --> 00:13:42,052 But before such detai led observational evidence was avai lable... 158 00:13:42,221 --> 00:13:47,523 bel ief i n any theory was as m uch a matter of faith and conviction as the... 159 00:13:47,626 --> 00:13:50,720 resu It of any scientific scruti ny 160 00:13:51,430 --> 00:13:53,398 Ptolemy's model of the u n iverse, 161 00:13:53,599 --> 00:13:58,935 went vi rtual ly u nchal lenged for one thousand five h u nd red years, su pported... 162 00:13:59,038 --> 00:14:01,029 al I the ti me by the Ch u rch, 163 00:14:01,207 --> 00:14:04,904 wh ich was at that ti me the repository of learn i ng 164 00:14:06,912 --> 00:14:09,380 Lord receive ou r g ifts 165 00:14:10,049 --> 00:14:14,509 Let our offerings make us holy and bri ng us salvation 166 00:14:30,803 --> 00:14:33,897 But by the sixteenth centu ry cathol ic scholars were faced 167 00:14:34,006 --> 00:14:37,339 with i ncreasi ng ly accu rate observations of the heavens 168 00:14:38,143 --> 00:14:39,770 It was on ly a matter of ti me 169 00:14:39,912 --> 00:14:44,406 before the ch u rch's teach i ngs were u ndone by its own scholar priests 170 00:14:45,317 --> 00:14:46,716 vice president teach i ng h istory of science, col lege d u rham 171 00:14:46,819 --> 00:14:49,549 man not j ust i n the sense he was a cathol ic, 172 00:14:49,688 --> 00:14:54,352 but he actual ly held a ch u rch office, as a canon of a cathed ral... 173 00:14:55,261 --> 00:14:59,254 He had a g reat ad m i ration for Ptolymaic astronomy 174 00:15:00,699 --> 00:15:03,964 Copern icus wanted to retu rn to a si m ple idea of planets 175 00:15:04,069 --> 00:15:08,506 movi ng i n perfect ci rcles without the need for Ptolemy's adj ustments 176 00:15:09,275 --> 00:15:11,675 He found their orbits would almost meet this ideal 177 00:15:11,911 --> 00:15:14,573 if he took the earth from the centre of the u n iverse 178 00:15:14,813 --> 00:15:16,644 and replaced it with the sun 179 00:15:18,684 --> 00:15:24,418 It was a revol utionary moment for cosmology. Copern icus had rad ical ly re-... 180 00:15:24,523 --> 00:15:29,517 organ ised the model of the u n iverse, wh ich had lasted for centu ries 181 00:15:30,396 --> 00:15:32,864 He began began an i rreversi ble process... 182 00:15:33,065 --> 00:15:36,501 that has downg raded us from the centre of the u n iverse,... 183 00:15:36,635 --> 00:15:41,265 to the outer su bu rbs of one among m i I l ions of galaxies 184 00:15:44,910 --> 00:15:45,934 We now have evidence... 185 00:15:46,045 --> 00:15:48,070 that we are not i m portant... 186 00:15:48,314 --> 00:15:49,941 i n yet another way 187 00:15:50,716 --> 00:15:53,844 It seems that the ki nd of matter that we are made... 188 00:15:54,053 --> 00:15:58,046 constitutes on ly a smal I fraction of the u n iverse. 189 00:15:58,157 --> 00:16:02,116 Over n i nety percent is someth i ng we can not even see 190 00:16:03,462 --> 00:16:04,588 Dark matter 191 00:16:04,897 --> 00:16:09,891 It sort of puts one as a h u man bei ng i n some perspective, 192 00:16:11,170 --> 00:16:14,606 that you know we we, the earth is not the centre of the solar system etc and... 193 00:16:14,707 --> 00:16:18,040 we' re not even made of particu larly com mon matter that's arou nd, 194 00:16:18,410 --> 00:16:19,570 because most of it's dark matter 195 00:16:23,749 --> 00:16:26,775 I n the sixteenth centu ry the Ch u rch was su re 196 00:16:26,986 --> 00:16:31,389 that God had put man and earth at the h u b of the u n iverse 197 00:16:32,191 --> 00:16:35,058 And Copern icus's idea that planets shou ld orbit 198 00:16:35,160 --> 00:16:39,995 the su n i n perfect ci rcles d id not q u ite match observations 199 00:16:40,666 --> 00:16:43,066 So Ptolemy's earth centered u n iverse 200 00:16:43,168 --> 00:16:44,533 seemed preferable 201 00:16:47,606 --> 00:16:50,302 Copern icus d ied i n 1 543. 202 00:16:50,609 --> 00:16:53,544 Some sixty years later, Johan nes Kepler, 203 00:16:53,712 --> 00:16:58,308 a German astronomer provided strong su pport for the su n centered theory 204 00:16:58,417 --> 00:17:02,979 after he d iscovered a new way to explai n the motion of planets 205 00:17:05,691 --> 00:17:08,592 He broke with two with two thousand years of... 206 00:17:08,694 --> 00:17:11,356 ph i losoph ical and astronom ical trad ition 207 00:17:11,597 --> 00:17:16,330 What Kepler finished up with was non-ci rcu lar motion 208 00:17:16,935 --> 00:17:22,396 He real ised that the planets are actually travelling in elliptical orbits 209 00:17:23,042 --> 00:17:26,478 The great thing about Kepler's system is he can do everything 210 00:17:26,578 --> 00:17:32,312 Copernicus did simply with one clear curve of the eclipse, 211 00:17:32,484 --> 00:17:33,917 a colossal achievement 212 00:17:37,056 --> 00:17:41,015 At fi rst the ch u rch fai led to see what was com i ng. But when the... 213 00:17:41,126 --> 00:17:45,426 Ital ian scientist Gal I i leo Gal I i lei pu bl ished Copern icus's idea for... 214 00:17:45,531 --> 00:17:47,089 everyone to read, 215 00:17:47,299 --> 00:17:52,635 the Vatican fi nal ly took d rastic action to cu rb h is popu I ist i nsti ncts 216 00:17:53,872 --> 00:17:57,865 We are now at the top floor of the villa ll Juliello 217 00:17:57,976 --> 00:17:59,500 and the place where Gal I i leo... 218 00:17:59,611 --> 00:18:03,069 spend h is last years of I ife as a prisoner 219 00:18:04,316 --> 00:18:08,218 I n isolation, al I Gal I i leo cou ld do was fi n ish h is work on the 220 00:18:08,320 --> 00:18:12,620 Iaws of motion which he had begun long before his house arrest 221 00:18:13,425 --> 00:18:16,826 One problem he solved was why the earth seems to be sti I l 222 00:18:18,330 --> 00:18:23,666 As it moves we move with it. We si m ply ride on its su rface 223 00:18:24,336 --> 00:18:27,134 But he cou ld n't explai n why we d id n't fal I off 224 00:18:33,245 --> 00:18:36,840 It was while working on the laws of motion that Gal I i leo... 225 00:18:36,949 --> 00:18:40,385 stu m bled on someth i ng wh ich was desti ned to make nonsense of 226 00:18:40,486 --> 00:18:42,852 the Ch u rch's view of the U n iverse 227 00:18:43,555 --> 00:18:48,788 At the end of 1 609 he heard that there were i n i nto the market some 228 00:18:48,894 --> 00:18:53,490 fu n ny objects wh ich were a tu be with some g lasses, 229 00:18:53,832 --> 00:18:56,767 who were g ivi ng some fu n ny performance. 230 00:18:59,838 --> 00:19:04,639 Th is i nstru ment was com i ng from Hol land and was sold as a toy 231 00:19:05,377 --> 00:19:10,076 When Gal I i leo took it he began to be transformed from a toy... 232 00:19:10,215 --> 00:19:11,546 to an i nstru ment 233 00:19:12,017 --> 00:19:14,679 He started to use the mag n ification powers of 234 00:19:14,786 --> 00:19:16,811 the telescope to look at the skies 235 00:19:17,422 --> 00:19:23,418 Th is is a major step i n h is career and also i n the h istory of modern cosmology 236 00:19:30,569 --> 00:19:33,470 The telescope transformed what cou ld be seen 237 00:19:34,072 --> 00:19:38,304 Gal I i leo became fasci nated by distant planets like Jupiter 238 00:19:41,580 --> 00:19:44,549 According to the Church his telescope should have revealed 239 00:19:44,650 --> 00:19:49,553 a Universe where everything orbits the Earth. A system of perfect spheres 240 00:19:50,355 --> 00:19:51,822 But it wasn't I i ke that 241 00:19:53,692 --> 00:19:58,493 The moon was not so pol ished and so rou nd as people bel ieved, 242 00:19:58,697 --> 00:20:02,531 but they were presented with val leys and mou ntai ns exactly as the earth 243 00:20:02,868 --> 00:20:09,330 And he moved afterwards to other bod ies, he started to observe Mercu ry, Mars 244 00:20:09,441 --> 00:20:12,604 But he was captu red by J u piter 245 00:20:12,978 --> 00:20:16,573 He started to observe seriously J u piter i n Jan uary 1 61 0 246 00:20:16,682 --> 00:20:21,483 and diary notes is very touching, says I have d iscovered a fu n ny body, 247 00:20:21,620 --> 00:20:25,579 something like that which is ci rcu lati ng arou nd J u piter, 248 00:20:25,757 --> 00:20:28,248 7 Jan uary if I remem ber correctly 249 00:20:28,360 --> 00:20:32,456 And the day after he was immediately at the su nset at the telescope 250 00:20:34,800 --> 00:20:38,793 Hardly believing his eyes he sketched what he saw 251 00:20:44,676 --> 00:20:47,804 In a few days he became aware that these moons... 252 00:20:47,946 --> 00:20:49,777 as he cal led them, were fou r, 253 00:20:49,982 --> 00:20:52,974 and they were satel I ites because they were doi ng... 254 00:20:53,118 --> 00:20:57,987 rhyth m ic and cycl ic performances arou nd the body of J u piter 255 00:20:59,091 --> 00:21:02,925 Anyth i ng orbiti ng J u piter could not be orbiting the Earth 256 00:21:03,495 --> 00:21:07,090 The church's model of the universe no longer made sense 257 00:21:08,166 --> 00:21:12,193 Th is was the decisive step why Gal I i leo became convinced... 258 00:21:12,437 --> 00:21:15,133 so he started to publish and started to produce... 259 00:21:15,240 --> 00:21:18,403 work sayi ng be carefu I we can not stay... 260 00:21:18,510 --> 00:21:23,777 anymore with Ptolemy. What the bi ble was sayi ng i n many ti mes... 261 00:21:23,915 --> 00:21:27,351 about the position of the su n and the motion of the... 262 00:21:27,452 --> 00:21:30,080 su n arou nd the earth was not tenable anymore 263 00:21:31,523 --> 00:21:34,651 Gal I i leo entered a fig ht with the authorities... 264 00:21:35,027 --> 00:21:39,794 the book of Copern icus was suspended and sent to correction 265 00:21:40,232 --> 00:21:44,168 Gal I i leo was cal led to Rome at the T ri bu nal of I nq u isition 266 00:21:46,972 --> 00:21:49,065 Fi nal ly he was condem ned 267 00:21:50,242 --> 00:21:54,975 Gallileo retracted his claims, rather than face the full wrath of the Church, 268 00:21:55,213 --> 00:21:57,408 perhaps even death at the stake 269 00:21:58,550 --> 00:22:02,646 He was sentenced to spend the rest of h is I ife u nder house arrest 270 00:22:04,489 --> 00:22:10,587 It's the beg i n n i ng of confl ict between science and rel ig ion, science and... 271 00:22:10,696 --> 00:22:14,393 and theology and it's attention wh ich is goi ng to be... 272 00:22:14,499 --> 00:22:17,525 many other episodes d u ri ng the modern age 273 00:22:26,645 --> 00:22:29,170 Anyone who looks th roug h a telescope today 274 00:22:29,414 --> 00:22:32,713 wi I l feel the same sense of wonder that Gal I i leo d id... 275 00:22:33,318 --> 00:22:38,051 We can now see stars and galaxies so far away that the I ig ht from them 276 00:22:38,156 --> 00:22:42,388 travel I i ng across space takes bi I l ions of years to reach us 277 00:22:42,794 --> 00:22:46,286 We are looki ng back i n ti me, seei ng how they were 278 00:22:46,431 --> 00:22:47,921 I ig ht years ago 279 00:22:49,067 --> 00:22:52,366 Observi ng is er al most mystical 280 00:22:53,472 --> 00:22:58,910 It's the act that really puts me i n contact with the rest of the u n iverse 281 00:22:59,111 --> 00:23:02,979 I often th i n k if someone's looki ng back at me I wonder 282 00:23:03,081 --> 00:23:05,106 if their telescope is bigger than mine 283 00:23:08,954 --> 00:23:13,288 T oday's telescopes depend on refi nements i ntrod uced by lsaac Newton, 284 00:23:13,492 --> 00:23:17,690 who was born i n 1 642, the year Gal I i leo d ied 285 00:23:23,568 --> 00:23:24,626 I feel I have I i n ks 286 00:23:24,736 --> 00:23:27,068 to both Newton and Gallileo 287 00:23:28,807 --> 00:23:34,439 I now hold the same professorship at... Cam bridge that Newton once held, 288 00:23:35,247 --> 00:23:40,446 and I was born...th ree h u nd red years to the day after Gal I i leo d ied 289 00:24:00,305 --> 00:24:04,105 I n 1 660, with no formal ed ucation Newton 290 00:24:04,209 --> 00:24:07,701 Ieft this house in Woolsthorpe to go to university 291 00:24:12,050 --> 00:24:13,642 At Cam bridge more or less by chance... 292 00:24:13,752 --> 00:24:18,519 he picked u p about fou r or five books on mathematics and he set to work to read... 293 00:24:18,623 --> 00:24:20,853 them. Six months later he was maki ng... 294 00:24:20,959 --> 00:24:24,224 i m portant contri butions to mathematics, 295 00:24:24,429 --> 00:24:27,796 eig hteen months later he was the g reatest mathematician al ive 296 00:24:27,899 --> 00:24:29,799 J ust staggeri ng, he taug ht h i mself, 297 00:24:31,369 --> 00:24:34,896 j ust from fou r or five books and it al I came out of that 298 00:24:39,211 --> 00:24:41,372 Newton's refi nements to the desig n of 299 00:24:41,480 --> 00:24:45,883 Gal I i leo's telescope proved that he was more than j ust a theoretician 300 00:24:46,518 --> 00:24:48,486 By i ncorporati ng an i nternal m i rror 301 00:24:48,687 --> 00:24:51,121 he dou bled the telescope's power 302 00:24:53,892 --> 00:24:56,986 The news of th is telescope was d istri buted arou nd Eu rope... 303 00:24:57,229 --> 00:24:59,720 and that's actual ly what made h is name 304 00:25:00,031 --> 00:25:04,730 And later on that desig n of telescope tu rned out to be the best one of 305 00:25:04,836 --> 00:25:10,638 al I for studyi ng the heavens, so er i n that way he g reatly advanced astronomy 306 00:25:12,344 --> 00:25:15,313 Newton had been at Cam bridge for several years 307 00:25:15,447 --> 00:25:19,474 when the plag ue forced h i m to come back home here to Woolsthorpe 308 00:25:19,684 --> 00:25:23,711 and at the time he left Cambridge he was beginning to think about 309 00:25:23,889 --> 00:25:29,657 the laws of motion, how things are moving and he had the idea that 310 00:25:29,761 --> 00:25:33,026 basically things would essentially move in a straight line 311 00:25:33,131 --> 00:25:34,564 if they were left on their own 312 00:25:40,472 --> 00:25:42,337 He was beginning to think of the forces... 313 00:25:42,507 --> 00:25:45,499 that might be at work and one of the most obvious 314 00:25:45,610 --> 00:25:50,377 is the pull of gravity which is pulling an object towards the earth 315 00:25:51,716 --> 00:25:54,617 There's a popular myth that Newton discovered gravity 316 00:25:54,786 --> 00:25:57,311 after watching an apple fall from a tree 317 00:25:58,390 --> 00:26:01,826 I think it's probably true that he did start thinking about 318 00:26:01,927 --> 00:26:04,555 these things from seeing apples fall, 319 00:26:04,796 --> 00:26:07,230 but l' m absolutely certain that 320 00:26:07,332 --> 00:26:11,132 he didn't have the complete theory of universal gravitation back here 321 00:26:11,236 --> 00:26:15,434 in the plague year that the fu I l worki ng out came m uch later 322 00:26:18,209 --> 00:26:22,145 His idea of gravity and he called it universal gravity, 323 00:26:22,247 --> 00:26:24,044 because that is a very i m portant th i ng, 324 00:26:24,182 --> 00:26:27,948 is that every single piece of matter i n the u n iverse pu I ls 325 00:26:28,053 --> 00:26:32,922 every other piece of matter i n the u n iverse towards it and vice-versa 326 00:26:35,093 --> 00:26:38,085 The earth is bi I l ions of ti mes more massive than 327 00:26:38,196 --> 00:26:43,065 the apple so so basical ly the earth is moving ever so slightly towards 328 00:26:43,168 --> 00:26:45,068 the apple but you just can't see that 329 00:26:45,170 --> 00:26:49,630 The apple the motion of the apple is much more pronounced than that of the earth 330 00:26:53,278 --> 00:26:58,739 The importance of the apple is that it symbolises the idea that 331 00:26:58,883 --> 00:27:01,977 the laws of nature that are working on the earth 332 00:27:02,120 --> 00:27:04,748 are also working throughout the whole u n iverse 333 00:27:05,256 --> 00:27:09,625 Newton tu ned h is theory of g ravity to the heavens to see if Kepler's ideas... 334 00:27:09,728 --> 00:27:12,822 wou ld match u p with h is own. He com bi ned Gal I i leo's... 335 00:27:12,931 --> 00:27:16,230 Iaws of motion with h is own eq uations for g ravity 336 00:27:16,801 --> 00:27:19,668 And he saw that together they explai ned precisely the path... 337 00:27:19,771 --> 00:27:21,705 of the moon rou nd the earth 338 00:27:22,407 --> 00:27:26,002 And that was enoug h to g ive Newton the h i nts to then 339 00:27:26,111 --> 00:27:29,342 apply those same tech n iq ues of Gal I i leo 340 00:27:29,447 --> 00:27:31,779 but now to the planets and that essential ly... 341 00:27:31,883 --> 00:27:33,544 the whole of the u n iverse 342 00:27:35,353 --> 00:27:37,787 Even the Ch u rch was fi nal ly convi nced 343 00:27:38,556 --> 00:27:42,754 Newton swept away the last vestiges of the old Ptolemaic system 344 00:27:43,461 --> 00:27:46,862 He believed that gravity would control the whole universe 345 00:27:47,399 --> 00:27:50,027 It was gravity which kept us on a moving Earth 346 00:27:50,368 --> 00:27:53,633 And gravity would keep all the stars i n the u n iverse movi ng 347 00:27:54,272 --> 00:27:57,332 Newton's u n iverse wou ld stretch out forever 348 00:28:00,578 --> 00:28:03,877 He was the fi rst person who had a mathematical descri ption of 349 00:28:03,982 --> 00:28:05,574 the u n iverse wh ich man ifestly... 350 00:28:05,684 --> 00:28:08,278 worked. And the title of h is g reat book, 351 00:28:08,386 --> 00:28:10,217 the Pri nci pia that real ly makes the poi nt, 352 00:28:10,321 --> 00:28:13,347 he descri bed it as the mathematical pri nci pals of... 353 00:28:13,458 --> 00:28:14,925 natu ral ph i losophy 354 00:28:22,600 --> 00:28:24,534 Accord i ng to Newtons theory... 355 00:28:24,703 --> 00:28:27,934 the u n iverse ran I i ke clockwork...forever... 356 00:28:33,945 --> 00:28:35,708 I th i n k people were comforted 357 00:28:35,814 --> 00:28:38,578 by the thoug ht that even thoug h they g rew old 358 00:28:38,683 --> 00:28:43,279 and d ied the u n iverse was eternal and unchanging 359 00:28:56,735 --> 00:28:58,930 Inspired by Newton's ideas 360 00:28:59,204 --> 00:29:01,900 an age of gentlemen astronomers began 361 00:29:06,878 --> 00:29:12,214 I am Wi I l iam Brandon the 7th Earl of Rosse, great g reat g randson of the... 362 00:29:12,317 --> 00:29:16,151 3rd Earl, who is also another Wi I l iam 363 00:29:21,726 --> 00:29:24,524 H is g reat ach ievement was the bu i ld i ng of... 364 00:29:24,696 --> 00:29:28,962 the g reat six foot telescope or the Leviation of the Parsons T own, 365 00:29:29,067 --> 00:29:30,534 as it was cal led 366 00:29:30,769 --> 00:29:33,237 That was the biggest and the most powerfu I telescope 367 00:29:33,338 --> 00:29:35,670 i n the world u p to the present centu ry 368 00:29:36,975 --> 00:29:37,669 The 3rd Earl... 369 00:29:37,776 --> 00:29:42,873 bu i It h is telescope i n 1 850, i n the marshy lrish countryside outside Dublin 370 00:29:44,516 --> 00:29:47,144 He made everything he needed himself here 371 00:29:47,252 --> 00:29:51,211 He made it in a foundry that he set up in the bottom of the moat, 372 00:29:51,389 --> 00:29:56,520 that was fuelled by the turf from the local bogs by making the most of 373 00:29:56,628 --> 00:29:58,186 all the resources he had 374 00:30:11,042 --> 00:30:12,373 My name is Francisco Diego, 375 00:30:12,477 --> 00:30:16,038 I am involved with optical design at University College London 376 00:30:16,181 --> 00:30:19,981 and we are planning to build a new mirror for this telescope 377 00:30:21,286 --> 00:30:21,945 The Leviathan... 378 00:30:22,053 --> 00:30:25,545 of Parsonstown worked in the same way as Newton's telescope: 379 00:30:25,924 --> 00:30:29,382 i mages from space were concentrated on a concave m i rror 380 00:30:30,128 --> 00:30:33,291 I n Newton's telescope th is m i rror was five i nches wide 381 00:30:33,665 --> 00:30:36,759 Two h u nd red years later the th i rd Earl had bu i It h i mself a... 382 00:30:36,868 --> 00:30:39,530 m i rror with a massive six foot d iameter 383 00:30:41,639 --> 00:30:46,235 With er telescopes I i ke Gal I i leos's or Newton's you cou ld on ly er... 384 00:30:46,344 --> 00:30:47,572 see the solar system 385 00:30:47,879 --> 00:30:52,475 I mean the moon, the su n, the planets and er al most noth i ng else 386 00:31:01,326 --> 00:31:04,887 And you see here a plate... 387 00:31:04,996 --> 00:31:09,092 of the six foot telescope with an 388 00:31:09,200 --> 00:31:12,192 observer... here i n position 389 00:31:13,805 --> 00:31:17,206 Remem beri ng of cou rse that th is is a reflecti ng telescope 390 00:31:17,308 --> 00:31:22,678 so the observers had to get i nto position at the at the top to look rig ht... 391 00:31:22,780 --> 00:31:25,874 down the length of the tube to see the i mage reflected 392 00:31:25,984 --> 00:31:28,976 i n the g iant six foot m i rror at the bottom 393 00:31:29,120 --> 00:31:32,283 I was browsi ng i n you r library and found this book 394 00:31:32,423 --> 00:31:35,449 This is a transactions of the Royal Society... 395 00:31:35,860 --> 00:31:37,384 1 850 or something like that 396 00:31:37,495 --> 00:31:40,794 And there is the 3rd Earl's lovely drawing of the Whirlpool 397 00:31:40,899 --> 00:31:43,231 The whirlpool galaxy 398 00:31:43,334 --> 00:31:45,598 The first time the whirlpool galaxy was ever seen 399 00:31:47,338 --> 00:31:49,101 The telescope gave new detail 400 00:31:49,207 --> 00:31:51,971 to what had been assumed to be clouds of gas 401 00:31:55,013 --> 00:31:57,948 However at the ti me observers d id n't real ise that 402 00:31:58,049 --> 00:32:00,449 they were actual ly seei ng th roug h the m i I l ions of stars 403 00:32:00,551 --> 00:32:05,853 in our own Milky Way Galaxy to other equally vast galaxies of stars 404 00:32:10,895 --> 00:32:13,728 Meanwhile scientists were beginning to realise that 405 00:32:13,831 --> 00:32:16,823 some of the secrets of the u n iverse lay h idden i n I ig ht... 406 00:32:16,935 --> 00:32:21,395 itself. A tech n iq ue was soon to be fou nd to u n lock them 407 00:32:21,806 --> 00:32:24,434 It was cal led spectroscopy 408 00:32:27,745 --> 00:32:30,339 Spectroscopy is the u m analysis... 409 00:32:30,448 --> 00:32:31,972 of I ig ht 410 00:32:35,553 --> 00:32:38,920 The er i nformation that we get from starl ig ht 411 00:32:39,023 --> 00:32:43,221 or from su n I ig ht or from I ig ht i n general is is tremendous, is enormous 412 00:32:50,134 --> 00:32:51,658 Spectroscopy was d iscovered... 413 00:32:51,769 --> 00:32:55,296 i n about 1 81 4, by a German optical physicist... 414 00:32:55,540 --> 00:32:57,531 Joseph Von Frauen hofer 415 00:32:59,544 --> 00:33:08,248 He was an optical man ufactu rer. He was worki ng i n a com pany wh ich was bu i ld i ng... 416 00:33:08,619 --> 00:33:11,747 Ienses for astronomers 417 00:33:16,828 --> 00:33:18,261 He was very method ical, he used... 418 00:33:18,363 --> 00:33:20,194 to write everyth i ng he he d id... 419 00:33:20,298 --> 00:33:25,099 and fortu nately we have these texts of h is own very words of the... 420 00:33:25,203 --> 00:33:26,670 fantastic d iscovery 421 00:33:31,042 --> 00:33:35,274 I n a sh uttered room I al lowed su n I ig ht to pass th roug h 422 00:33:35,380 --> 00:33:37,245 a narrow open i ng i n the sh utters... 423 00:33:37,782 --> 00:33:38,942 onto a prism 424 00:33:41,386 --> 00:33:44,480 I fou nd with the telescope al most cou ntless... 425 00:33:44,622 --> 00:33:48,524 strong and weak vertical I i nes crossi ng the spectru m 426 00:33:49,227 --> 00:33:53,095 wh ich however are darker than the remai n i ng part of the spectru m 427 00:33:53,297 --> 00:33:58,530 of the colou r i mage. Some seem to be nearly com pletely black 428 00:34:01,239 --> 00:34:03,673 He cou ld n't explai n the orig i n of these I i nes, 429 00:34:03,841 --> 00:34:06,935 he j ust saw that part of the spectru m was m issi ng 430 00:34:15,219 --> 00:34:19,178 Hidden in these black lines was extraord i nary new i nformation 431 00:34:19,323 --> 00:34:21,917 about the chem ical structu re of the U n iverse 432 00:34:23,394 --> 00:34:26,261 Lig ht is orig i nated i n atoms 433 00:34:26,898 --> 00:34:28,729 Light is originated every time 434 00:34:28,833 --> 00:34:32,530 that um electrons in these atoms are jumping up and down 435 00:34:32,637 --> 00:34:35,800 It's a em ittti ng or absorbi ng I ig ht at a particu lar freq uency 436 00:34:36,140 --> 00:34:40,372 So each chem ical element has a particu lar way of behaviou r, 437 00:34:40,478 --> 00:34:43,504 the the electrons are j u m pi ng i n particu lar places 438 00:34:43,781 --> 00:34:47,945 So depend i ng on these places is the position of the line in the spectrum 439 00:34:48,319 --> 00:34:51,652 So if the line appears here you may say ah this is hydrogen, 440 00:34:52,156 --> 00:34:56,593 but if the line appears here no this is not hydrogen this is sodium etc. 441 00:34:56,694 --> 00:34:58,992 So in the solar spectrum we have the finger prints of 442 00:34:59,097 --> 00:35:03,124 a lot of chemical elements that we can identify i n ou r labs, 443 00:35:03,267 --> 00:35:08,500 because with the same eq u i pment we take a spectru m of a, of a lam p, 444 00:35:08,639 --> 00:35:13,736 say for exam ple an arc of i ron and we can prod uce the same I i nes i n ou r labs 445 00:35:13,911 --> 00:35:16,607 and we match the I i nes from the su n with the I i nes from the, 446 00:35:16,714 --> 00:35:22,277 from the er er er lam p i n ou r, i n ou r laboratory and the match is perfect 447 00:35:27,325 --> 00:35:30,158 Usi ng spectroscopy it was fou nd that 448 00:35:30,261 --> 00:35:33,822 the chem ical content of ou r su n was identical to that 449 00:35:33,931 --> 00:35:36,195 of any star i n the U n iverse 450 00:35:37,401 --> 00:35:44,102 Ou r su n and ou r solar system itself, was j ust one of an i nfi n ite n u m ber of others 451 00:35:45,076 --> 00:35:49,809 Perhaps we ou rselves have no special place i n the u n iverse 452 00:35:52,049 --> 00:35:58,318 The chem istry of stars is more or less the same as the chem istry of the su n, 453 00:35:58,623 --> 00:36:04,220 so the su n becomes a star or stars become su ns. 454 00:36:06,764 --> 00:36:10,427 Th is is a a... big revol ution. Th is is I i ke Copern ican revol ution 455 00:36:10,568 --> 00:36:15,665 when when you abandon the idea that the earth is the centre of the u n iverse 456 00:36:15,773 --> 00:36:18,640 and you say wel I er it's no longer the centre of the u n iverse, 457 00:36:18,743 --> 00:36:21,371 now the su n may be the centre at least of the solar system 458 00:36:21,612 --> 00:36:25,981 and that that was a major revol ution i n i n science 459 00:36:26,951 --> 00:36:29,317 Now we have another revol ution i n wh ich we say wel l 460 00:36:29,420 --> 00:36:33,880 we are not u h so special about it because u h ou r own bod ies, 461 00:36:33,991 --> 00:36:36,983 ou r own chem istry, ou r blood, ou r bones, ou r ski ns, 462 00:36:37,161 --> 00:36:40,187 they are made of u h hyd rogen, n itrogen, 463 00:36:40,331 --> 00:36:46,463 oxygen u h etc sod i u m etc and we fi nd hyd rogen and oxygen etc 464 00:36:46,571 --> 00:36:51,565 i n i n er i n nebu lae, i n stars, i n i n the u n iverse 465 00:36:51,676 --> 00:36:55,510 So it is the same chem istry, so there's noth i ng special about it 466 00:36:57,348 --> 00:37:00,511 If people and planets share the same chem istry, 467 00:37:00,785 --> 00:37:04,243 perhaps everyth i ng i n the Universe has the same beginning 468 00:37:06,557 --> 00:37:11,119 The cl ue to ou r com mon origins came from another discovery about light... 469 00:37:11,395 --> 00:37:14,523 by the Austrian scientist, Christian Dopler 470 00:37:15,933 --> 00:37:17,924 The Dopler shift has been... 471 00:37:18,202 --> 00:37:22,263 perhaps one of the most important tools i n astrophysics, 472 00:37:22,373 --> 00:37:28,312 I wou ld say i n cosmology now, because it is ou r speedometer if you I i ke, 473 00:37:28,412 --> 00:37:32,508 it is the, the the meter that we use to measu re the speed of 474 00:37:32,617 --> 00:37:35,347 al most everyth i ng i n the u n iverse 475 00:37:38,756 --> 00:37:40,053 Dopler suggested that 476 00:37:40,157 --> 00:37:44,457 if an object emitting light is moving towards or away from us, 477 00:37:44,729 --> 00:37:47,926 then the light it gives off will appear to be altered 478 00:37:48,766 --> 00:37:53,100 We can't observe th is is i n everyday life, because light moves too fast 479 00:37:53,571 --> 00:37:56,597 But we experience the same effect with sou nd 480 00:38:01,345 --> 00:38:04,337 As the sou rce of the sou nd moves the sou nd waves 481 00:38:04,448 --> 00:38:09,044 change thei r shape They are sq uashed together as the sou nd approaches 482 00:38:09,153 --> 00:38:14,523 and stretched as the sou nd... moves away. The change i n pitch is aud i ble and... 483 00:38:14,625 --> 00:38:16,991 th is is the Dopler sh ift 484 00:38:23,768 --> 00:38:25,497 By analysi ng star I ig ht... 485 00:38:25,703 --> 00:38:28,934 scientists fou nd the Dopler sh ift at work i n the spectru m 486 00:38:29,540 --> 00:38:31,303 If the I ig ht sou rce was approach i ng, 487 00:38:31,542 --> 00:38:35,342 the Frauenhofer lines are shifted towards the bl ue end of the spectru m 488 00:38:35,613 --> 00:38:36,910 It's a bl ue sh ift 489 00:38:37,348 --> 00:38:38,781 If the light source is receeding, 490 00:38:39,050 --> 00:38:43,316 these I i nes move towards the red end of the spectru m. A red sh ift 491 00:38:45,289 --> 00:38:48,019 These extraord i nary patterns i n starl ig ht 492 00:38:48,292 --> 00:38:51,625 broug ht the dawn of a new age for cosmology 493 00:38:53,030 --> 00:38:55,590 It became possi ble to tel I not on ly 494 00:38:55,700 --> 00:39:00,034 what the u n iverse was made of but also how it was movi ng 495 00:39:01,839 --> 00:39:02,863 The breakth roug h came... 496 00:39:02,973 --> 00:39:06,238 by analysi ng I ig ht from deep i n the u n iverse 497 00:39:06,644 --> 00:39:10,580 Lig ht seen th roug h powerfu l new telescopes i n America 498 00:39:11,415 --> 00:39:15,715 They cou ld reveal detai ls... of the u n iverse never seen before 499 00:39:18,189 --> 00:39:20,555 Everybody knew what the M i I ky Way galaxy was, 500 00:39:20,691 --> 00:39:23,057 the col lection of bi I l ions of stars to which the sun belonged, 501 00:39:23,260 --> 00:39:27,356 but nobody knew what these little patches...of nebu las material, 502 00:39:27,598 --> 00:39:32,501 that looked I i ke spi rals and er pancakes and so on were 503 00:39:32,603 --> 00:39:36,471 and some people thoug ht that the M i I ky way galaxy was the whole u n iverse 504 00:39:36,807 --> 00:39:41,301 and these I ittle spi rals were wisps of gas er in that universe 505 00:39:50,888 --> 00:39:54,688 The most famous person that worked at Mou nt Wi lson was Edwi n H u bble... 506 00:39:55,893 --> 00:39:58,487 who came here when he was q u ite you ng actual ly, 507 00:39:58,596 --> 00:40:02,896 rig ht after h is service i n World War 1, and H u bble had the golden touch 508 00:40:03,000 --> 00:40:05,195 He had a knack of picking the important problems 509 00:40:06,871 --> 00:40:09,066 Using the new hundred inch telescope, 510 00:40:09,306 --> 00:40:13,538 Hubble looked deep into space at the nebulous objects first identified 511 00:40:13,644 --> 00:40:17,273 in lreland by William Parsons, the 3rd Earl of Rosse 512 00:40:34,265 --> 00:40:34,993 Making use of... 513 00:40:35,099 --> 00:40:36,964 Observatory roof open i ng the extraord i nary clarity of 514 00:40:37,067 --> 00:40:40,195 the atmosphere over Mou nt Wi lson, wh ich is the best on the conti nent 515 00:40:40,471 --> 00:40:45,499 He was able to distinguish individual stars i n these I ittle clouds...of gas, 516 00:40:45,609 --> 00:40:49,545 these so cal led nebulae and that told him in itself that 517 00:40:49,647 --> 00:40:53,174 they were not er wisps of gas in our galaxy, 518 00:40:53,384 --> 00:40:56,751 but galaxies in their own right, each one containing billions... 519 00:40:56,854 --> 00:40:59,049 of stars and that the universe, 520 00:40:59,156 --> 00:41:03,820 the true universe was populated with countless numbers of island universes, 521 00:41:03,961 --> 00:41:07,226 each one like our Milky Way galaxy 522 00:41:35,459 --> 00:41:39,088 The distances that he measured were absolutely stu pefyi ng 523 00:41:39,296 --> 00:41:40,820 to the astronomers at that time 524 00:41:40,998 --> 00:41:45,526 He fou nd that the and rom ida nebu lar wh ich is the closest galaxy to us I i ke ou r own, 525 00:41:45,736 --> 00:41:50,002 was at least one m i I l ion I ig ht years away and a I ig ht year is six tri I l ion m i les, 526 00:41:50,107 --> 00:41:55,477 a very very g reat d istance, far outside the edge of ou r M i I ky Way...galaxy 527 00:41:57,014 --> 00:42:00,973 For the fi rst ti me we knew how big the u n iverse was with that d iscovery 528 00:42:08,225 --> 00:42:11,058 A col leag ue of H u bble's, Vesto Sl i pher, 529 00:42:11,295 --> 00:42:14,731 began to use Doppler's theory to analyse I ig ht 530 00:42:16,000 --> 00:42:19,731 All of the galaxies that he could see arou nd h i m had... red sh ifts, 531 00:42:20,037 --> 00:42:23,268 er they were sh ifted towards longer wavelengths and that 532 00:42:23,374 --> 00:42:26,639 wou ld mean of cou rse that relative to us they were movi ng away 533 00:42:26,844 --> 00:42:31,804 Er when Sl i pher gave th is report everybody stood u p and cheered 534 00:42:32,016 --> 00:42:33,108 They d id n't know what it meant, 535 00:42:33,217 --> 00:42:36,914 but they had a gut feeling that is was something cosmic in significance 536 00:42:37,688 --> 00:42:38,916 Unknown to Slipher, 537 00:42:39,089 --> 00:42:43,856 an obscu re German physicist was working on a theoretical explanation 538 00:42:45,496 --> 00:42:48,465 It was an extraord i nary u ndertaki ng for a patent clerk, 539 00:42:48,699 --> 00:42:50,929 who had shown I ittle academ ic prom ise, 540 00:42:51,402 --> 00:42:54,667 but he was about to devise a revol utionary view of the u n iverse, 541 00:42:54,872 --> 00:42:59,138 i n wh ich he pictu red space and ti me as the same th i ng. 542 00:42:59,777 --> 00:43:01,574 He was Al bert Ei nstei n 543 00:43:06,350 --> 00:43:09,842 He was forced to learn a lot of very com pl icated mathematics, 544 00:43:10,154 --> 00:43:14,090 erm i n order to do so. But i n 1 91 5 fi nal ly the theory was born 545 00:43:17,995 --> 00:43:21,089 Al bert Ei nstei n's general theory of relativity published 546 00:43:21,198 --> 00:43:25,430 in 1 91 5 overturned Newton's theory of gravity 547 00:43:27,271 --> 00:43:31,765 In Einstein's theory objects did not pull directly on one another 548 00:43:32,343 --> 00:43:36,439 Instead they made dimples or warps in space and time 549 00:43:37,881 --> 00:43:42,147 One object passi ng another wou ld have its path deflected by these warps 550 00:43:42,353 --> 00:43:45,049 and therefore wou ld seem to be attracted towards it 551 00:43:46,890 --> 00:43:49,882 And the equations had further implications 552 00:43:50,260 --> 00:43:52,626 So one thing to understand about general relativity is that 553 00:43:52,730 --> 00:43:56,461 you can't have a whole col lection of matter say of galaxies 554 00:43:56,600 --> 00:44:00,161 or stars wh ich are sitti ng i n static config u ration 555 00:44:00,270 --> 00:44:03,239 with respect to each other and expect them to stay there 556 00:44:03,374 --> 00:44:07,640 They won't, they are goi ng to col lapse i n towards each other. 557 00:44:08,445 --> 00:44:09,571 So th is means that... 558 00:44:09,713 --> 00:44:14,946 U m you can't have a static model of the u n iverse i n general relativity 559 00:44:15,252 --> 00:44:20,053 The model, the u n iverse either has to be expand i ng or it has to be contracti ng 560 00:44:20,257 --> 00:44:23,158 It has to be dynam ical i n some way it can't possi bly be static 561 00:44:23,861 --> 00:44:27,422 Even Einstein resisted the implications of his theory at first and 562 00:44:27,531 --> 00:44:29,829 he adjusted the maths to avoid them 563 00:44:30,300 --> 00:44:34,066 But he couldn't prevent other scientists from seeing the possibilities 564 00:44:34,738 --> 00:44:35,932 The astronomers looked... 565 00:44:36,040 --> 00:44:40,739 at Sl i pher's d iscovery of the motion of the galaxies and the pred iction that 566 00:44:40,844 --> 00:44:44,439 the u n iverse expands and said ah ha these are two sides of one coi n, 567 00:44:44,581 --> 00:44:45,513 they fit together 568 00:44:45,649 --> 00:44:48,550 And Hubble again with that golden touch for working on the big problems 569 00:44:48,719 --> 00:44:53,884 turned his attention to this question and he asked himself how can I investigate it 570 00:44:54,058 --> 00:44:58,688 And the way he did so was to start to measu re the red sh ifts as they' re cal led, 571 00:44:58,862 --> 00:45:03,595 the...velocities with wh ich these u h galaxies are movi ng away from us 572 00:45:04,968 --> 00:45:08,495 H u bble began the process of systematically analysing light 573 00:45:08,605 --> 00:45:14,805 from thousands of galaxies usi ng spectroscopy. The resu lts were staggeri ng 574 00:45:17,047 --> 00:45:19,515 And he fou nd someth i ng known today as H u bble's Law, 575 00:45:19,717 --> 00:45:22,447 q u ite extraord i nary that the red sh ift 576 00:45:22,586 --> 00:45:26,545 or the velocity of recession from us is proportional to d istance 577 00:45:28,592 --> 00:45:31,561 If a galaxy at this distance is movi ng away from you 578 00:45:31,662 --> 00:45:35,393 at a certai n speed a galaxy twice as far away wi I l be g uaranteed 579 00:45:35,499 --> 00:45:37,865 to be movi ng away from you at twice the speed 580 00:45:41,839 --> 00:45:45,138 H u bble actual ly changed... the pictu re of the u n iverse, 581 00:45:45,342 --> 00:45:49,438 because the Ptolemaic pictu re was static and 582 00:45:49,580 --> 00:45:51,741 Newton's pictu re of the u n iverse was static 583 00:45:52,216 --> 00:45:54,776 U h but H u bble showed that the u n iverse is dynam ic 584 00:45:55,085 --> 00:45:57,315 Everyth i ng is movi ng away from everything else 585 00:46:00,958 --> 00:46:03,586 G reek astronomers thoug ht most of them, not al I of them... 586 00:46:03,794 --> 00:46:05,921 that the earth was the centre of the u n iverse 587 00:46:06,163 --> 00:46:08,427 Copern icus showed that was not so and 588 00:46:08,532 --> 00:46:10,500 thoug ht the su n was the centre of the u n iverse 589 00:46:10,667 --> 00:46:14,364 Other later astronomers showed no the su n was not the centre of the u n iverse, 590 00:46:14,571 --> 00:46:15,765 but many of them thoug ht that 591 00:46:15,873 --> 00:46:18,205 the centre of ou r galaxy was the centre of the u n iverse 592 00:46:18,375 --> 00:46:21,401 H u bble showed that there is no centre and that 593 00:46:21,512 --> 00:46:24,811 was a tremendous scientific theolog ical and philosophical accomplishment 594 00:46:24,982 --> 00:46:29,351 He showed that the universe is as far as the telescope can see is populated 595 00:46:29,553 --> 00:46:33,182 with countless numbers of island universes and there is no difference whatsoever 596 00:46:33,290 --> 00:46:34,655 There is no centre 597 00:46:35,359 --> 00:46:40,661 The second er i m pl ication of h is fi nd i ng was u h wel I to explai n it, 598 00:46:40,764 --> 00:46:43,699 imagine that the picture of the expanding galaxies, 599 00:46:43,834 --> 00:46:46,803 moving away from us and one another is a movie stri p 600 00:46:47,104 --> 00:46:48,901 Now ru n that i n reverse and 601 00:46:49,006 --> 00:46:51,804 al I the galaxies going backward i n ti me come closer and 602 00:46:51,909 --> 00:46:55,106 closer together and fi nal ly they all meet together at one point, 603 00:46:55,245 --> 00:46:57,179 speaki ng loosely because there is no one poi nt, 604 00:46:57,314 --> 00:46:59,908 there is no centre i n the u n iverse, they al I come together 605 00:47:00,184 --> 00:47:04,746 at an i nfi n itely dense and yet i nfi n itely extended er moment and beyond 606 00:47:04,855 --> 00:47:07,585 that of infinite density one cannot go 607 00:47:07,825 --> 00:47:11,454 So that moment marks the beginning of the birth of the universe and 608 00:47:11,562 --> 00:47:14,656 all of the things that we see arou nd us, every star, every planet, 609 00:47:14,865 --> 00:47:16,264 every I ivi ng th i ng on the earth and 610 00:47:16,366 --> 00:47:19,665 i n the cosmos owes it's genesis to that moment 611 00:47:19,837 --> 00:47:21,099 You can cal I it the Big Bang, 612 00:47:21,205 --> 00:47:24,766 but you can also cal I it with accu racy the moment of creation 613 00:47:26,710 --> 00:47:32,580 T oday, the space telescope named after H u bble, sends us these actual photog raphs 614 00:47:32,683 --> 00:47:39,816 from the fu rthest corners of ou r u n iverse. Confi rm i ng that seei ng tru ly is bel ievi ng 615 00:47:45,062 --> 00:47:47,530 From sitting at the centre of the u n iverse... 616 00:47:47,698 --> 00:47:51,498 we now fi nd ou rselves orbiti ng an average sized su n, 617 00:47:51,668 --> 00:47:56,537 wh ich is j ust one of m i I l ions of stars i n ou r...own M i I ky Way galaxy 618 00:47:59,176 --> 00:48:04,170 And ou r galaxy itself... is j ust one of bi I l ions of galaxies, 619 00:48:04,348 --> 00:48:07,146 i n a U n iverse that is infinite and expanding 620 00:48:09,219 --> 00:48:13,713 But th is is far from the end of a long history of enquiry 621 00:48:15,359 --> 00:48:18,021 Huge questions remain to be answered, 622 00:48:18,161 --> 00:48:23,463 before we can hope to have a com plete pictu re of the u n iverse we I ive i n