1 00:00:00,085 --> 00:00:02,646 Equipped with his five senses 2 00:00:02,722 --> 00:00:05,590 man explores the universe around him 3 00:00:05,660 --> 00:00:07,992 and calls the adventure Science. 4 00:01:09,375 --> 00:01:12,402 Things around us aren't always what they seem. 5 00:01:29,167 --> 00:01:33,400 ln the everyday world, we use a simple scale, ourselves 6 00:01:33,506 --> 00:01:36,271 to know what's small and what's large. 7 00:01:47,057 --> 00:01:49,549 But what about the worlds that lie beyond? 8 00:01:52,063 --> 00:01:55,625 What is truly large and truly small? 9 00:02:04,045 --> 00:02:07,379 To explore, to observe 10 00:02:07,783 --> 00:02:11,220 to understand the wider world we call the universe: 11 00:02:12,322 --> 00:02:15,121 This is one of the great human adventures. 12 00:02:30,278 --> 00:02:35,081 As we look out at the distant horizon, we may ask ourselves 13 00:02:35,686 --> 00:02:38,952 what is our true place in the universe? 14 00:02:42,528 --> 00:02:44,894 We are all travelers 15 00:02:44,965 --> 00:02:47,991 on an unending voyage of discovery. 16 00:03:27,986 --> 00:03:32,014 More than 25 centuries ago, among the Greek lslands 17 00:03:32,091 --> 00:03:36,153 here at the vibrant crossroads of Africa, Asia and Europe 18 00:03:36,564 --> 00:03:41,060 philosophers devised rational theories about the world around them. 19 00:03:44,875 --> 00:03:47,845 The wondrous waves and foams of nature, they said 20 00:03:48,179 --> 00:03:49,771 could be understood. 21 00:04:20,353 --> 00:04:25,054 One Greek thinker suggested that the Earth moved around the sun. 22 00:04:28,597 --> 00:04:32,831 Another taught that everything, the work of man and nature 23 00:04:33,137 --> 00:04:36,665 was made of particles too small to see. 24 00:04:41,414 --> 00:04:44,384 Others estimated the sizes of the Earth and the moon 25 00:04:44,451 --> 00:04:47,546 and the distances between them, and reasoned 26 00:04:47,622 --> 00:04:49,283 both were spheres. 27 00:04:52,428 --> 00:04:56,593 But it would be centuries before we had the tools to extend our vision 28 00:04:56,800 --> 00:04:59,827 and confirm the wisdom of these early thinkers. 29 00:05:01,774 --> 00:05:03,435 ln the meantime 30 00:05:03,509 --> 00:05:07,641 people around the world gazed on the stars and gave them names. 31 00:05:08,683 --> 00:05:13,383 Most assumed the Earth was the center of an unchanging universe. 32 00:05:47,866 --> 00:05:49,698 Two thousand years passed 33 00:05:49,769 --> 00:05:53,570 before a revolutionary breakthrough was made by a mathematics professor 34 00:05:53,641 --> 00:05:56,941 in the ancient, maritime republic of Venice. 35 00:05:58,113 --> 00:06:01,572 ln 1609, Galileo Galilei 36 00:06:01,817 --> 00:06:05,811 demonstrated an instrument that would soon be called a telescope. 37 00:06:09,995 --> 00:06:11,860 From the tallest bell towers 38 00:06:11,930 --> 00:06:14,559 he showed the device could spot approaching ships 39 00:06:14,634 --> 00:06:17,866 hours before their sails were visible to the naked eye. 40 00:06:19,707 --> 00:06:22,973 Later, when he aimed his telescope at the night sky 41 00:06:23,245 --> 00:06:26,682 Galileo discovered that the moon was a world of mountains. 42 00:06:27,351 --> 00:06:29,319 Jupiter had its own moons 43 00:06:29,453 --> 00:06:32,651 and the Milky Way was a band of countless stars. 44 00:06:38,065 --> 00:06:40,932 Our own cosmic voyage begins here 45 00:06:41,135 --> 00:06:44,867 in the center of Galileo's Venice, St. Mark's Square. 46 00:06:50,780 --> 00:06:54,478 Since the universe is a big place, we could easily get lost 47 00:06:55,087 --> 00:06:58,580 so we'll need signposts to give us a sense of scale. 48 00:07:01,627 --> 00:07:04,654 The acrobats' ring is one meter wide. 49 00:07:08,002 --> 00:07:11,939 The crowd is ten times wider, ten meters across. 50 00:07:12,007 --> 00:07:14,238 Larger by one power of ten. 51 00:07:18,583 --> 00:07:21,815 Now, with every step, every ring 52 00:07:22,287 --> 00:07:25,257 we travel ten times farther from Venice 53 00:07:25,492 --> 00:07:28,690 and our view of the universe is ten times wider. 54 00:07:32,100 --> 00:07:34,934 The 100-meter ring surrounds St. Mark's 55 00:07:35,338 --> 00:07:39,275 and 1,000 meters, one kilometer, the city's center. 56 00:07:41,513 --> 00:07:45,974 As our speed increases, four steps, four powers of ten 57 00:07:46,152 --> 00:07:51,182 reveal all the islands of Venice, the Adriatic Sea and Northern ltaly. 58 00:07:58,568 --> 00:08:03,302 Six steps take in Europe from Germany across to the Balkans. 59 00:08:07,546 --> 00:08:10,414 And soon, we can see the entire planet. 60 00:08:11,050 --> 00:08:12,848 Our home in space. 61 00:08:24,634 --> 00:08:26,830 Eight steps on our outward journey 62 00:08:26,938 --> 00:08:31,205 eight powers of ten, and we pass the farthest reaches of human travel: 63 00:08:32,511 --> 00:08:33,672 The moon. 64 00:08:59,512 --> 00:09:02,949 lf we visualize the paths that the nine planets take 65 00:09:03,017 --> 00:09:05,145 in their orbits around the sun 66 00:09:06,455 --> 00:09:09,289 at 13 steps from St. Mark's Square 67 00:09:09,826 --> 00:09:13,263 the entire solar system comes into view. 68 00:09:22,576 --> 00:09:26,536 And with 15 steps, 15 powers of ten 69 00:09:27,248 --> 00:09:30,878 we can see our sun is just another star. 70 00:09:31,388 --> 00:09:35,155 From here on, our voyage will be measured in light-years. 71 00:09:35,760 --> 00:09:38,992 The distance light travels in an entire year. 72 00:09:41,300 --> 00:09:45,102 Only now do we fly past our nearest neighbor stars 73 00:09:45,706 --> 00:09:48,300 almost five light-years away. 74 00:09:49,911 --> 00:09:53,177 The same journey at the speed of today's spacecraft 75 00:09:53,382 --> 00:09:56,580 would last 100,000 years. 76 00:10:03,729 --> 00:10:06,221 As we cross the perpetual night 77 00:10:06,299 --> 00:10:09,701 our voyage takes us up and out of our sun's neighborhood 78 00:10:09,837 --> 00:10:13,035 near the edge of a great pinwheel of stars. 79 00:10:35,636 --> 00:10:38,367 The Milky Way is actually a spiral galaxy 80 00:10:38,807 --> 00:10:43,268 and our own sun is just one of a hundred billion stars in it. 81 00:10:44,515 --> 00:10:48,247 At this immense scale, 23 powers of ten 82 00:10:48,587 --> 00:10:51,284 each shining light we see is not a star 83 00:10:51,858 --> 00:10:55,852 but an entire galaxy composed of countless stars. 84 00:10:57,631 --> 00:11:01,694 Astronomers have discovered galaxies are flying away from one another. 85 00:11:02,505 --> 00:11:05,441 The universe is expanding. 86 00:11:07,310 --> 00:11:09,939 Our own galaxy, and all the others 87 00:11:10,114 --> 00:11:13,573 form clusters and superclusters of stupendous size 88 00:11:13,786 --> 00:11:16,551 hundreds of millions of light-years across. 89 00:11:20,227 --> 00:11:24,221 And here, about 15 billion light-years from Venice 90 00:11:24,933 --> 00:11:28,233 we approach the outer limits of the visible universe. 91 00:11:29,106 --> 00:11:33,771 What lies beyond this cosmic horizon, we cannot see 92 00:11:35,113 --> 00:11:37,048 and do not know. 93 00:11:52,936 --> 00:11:56,931 While Galileo's telescope allowed us to take an outward voyage 94 00:11:57,008 --> 00:12:00,239 another innovation, here in the Dutch town of Delft 95 00:12:00,646 --> 00:12:03,638 would lead us on an inward journey of discovery. 96 00:12:14,531 --> 00:12:16,328 Over three centuries ago 97 00:12:16,433 --> 00:12:19,995 Anton van Leeuwenhoek perfected the early microscope 98 00:12:20,271 --> 00:12:23,571 and used it to study droplets from the waterways of Holland. 99 00:12:42,333 --> 00:12:44,267 Come on, over here. 100 00:12:47,806 --> 00:12:50,207 As students today make their own discoveries 101 00:12:50,277 --> 00:12:52,644 imagine the moment when van Leeuwenhoek 102 00:12:52,713 --> 00:12:55,147 peered through his more powerful instrument 103 00:12:55,216 --> 00:12:59,587 and discovered a living kingdom in a drop of water. 104 00:13:07,799 --> 00:13:10,701 This busy world of single-cell paramecia 105 00:13:11,037 --> 00:13:13,233 is only one millimeter across. 106 00:13:13,874 --> 00:13:17,242 Three powers of ten smaller than a meter. 107 00:13:21,350 --> 00:13:25,845 The microscope allows us to continue our journey to the realm of the very small. 108 00:13:27,325 --> 00:13:29,486 As we move into the cell nucleus 109 00:13:30,094 --> 00:13:32,586 each new ring now reveals a world 110 00:13:32,798 --> 00:13:36,428 ten times smaller in diameter than the last. 111 00:13:39,707 --> 00:13:42,040 Deep within the nucleus 112 00:13:42,110 --> 00:13:44,841 we come upon truly remarkable constructions. 113 00:13:45,715 --> 00:13:49,049 Long, spiraling molecules of DNA. 114 00:13:52,023 --> 00:13:54,116 DNA holds the chemical codes 115 00:13:54,192 --> 00:13:57,321 for the reproduction of most organisms on the planet. 116 00:13:57,830 --> 00:14:01,825 Whether they're paramecia, people or petunias. 117 00:14:09,279 --> 00:14:11,713 Voyaging on, we see that molecules 118 00:14:11,781 --> 00:14:14,717 are made of even smaller parts called atoms. 119 00:14:20,993 --> 00:14:24,191 The tiny world of the common atom is very strange indeed. 120 00:14:25,299 --> 00:14:28,736 lts six electrons seem to swarm everywhere at once. 121 00:14:32,574 --> 00:14:34,907 Now our voyage takes us through a void 122 00:14:34,978 --> 00:14:38,210 that appears as vast as the space between the stars. 123 00:14:39,684 --> 00:14:42,085 Ahead lies the atomic nucleus. 124 00:14:42,654 --> 00:14:44,520 So fantastically small 125 00:14:45,024 --> 00:14:48,153 that if the whole atom were the size of this theater 126 00:14:48,228 --> 00:14:51,255 its nucleus would be like a speck of dust. 127 00:14:52,701 --> 00:14:56,331 Yet the nucleus contains almost all of the atom's mass 128 00:14:56,906 --> 00:14:59,273 packed into particles called protons 129 00:14:59,609 --> 00:15:00,975 and neutrons. 130 00:15:02,747 --> 00:15:07,651 And these, in turn, are made of smaller, more mysterious things called quarks. 131 00:15:11,559 --> 00:15:12,992 Exploring this 132 00:15:13,194 --> 00:15:15,322 the inner frontier of the universe 133 00:15:15,397 --> 00:15:18,025 physicists wonder if quarks might contain 134 00:15:18,101 --> 00:15:20,569 even tinier building blocks of matter. 135 00:15:28,113 --> 00:15:33,075 Scientists are investigating this mystery in an underground tunnel near Chicago 136 00:15:33,720 --> 00:15:37,020 home of the giant Fermilab particle accelerator 137 00:15:37,625 --> 00:15:43,122 designed to create conditions like those after the birth of our universe. 138 00:15:46,871 --> 00:15:49,602 Millions of protons and antiprotons 139 00:15:49,674 --> 00:15:52,404 race through these pipes in opposite directions 140 00:15:52,477 --> 00:15:57,041 nearly at the speed of light. A kind of subatomic demolition derby. 141 00:16:26,054 --> 00:16:29,991 Now our cosmic voyage enters another dimension 142 00:16:31,295 --> 00:16:33,354 the dimension of time 143 00:16:33,697 --> 00:16:35,962 where knowledge is much less certain. 144 00:16:36,801 --> 00:16:39,896 Studying traces of quarks from these collisions 145 00:16:40,239 --> 00:16:44,074 physicists try to learn what our universe was like when it began 146 00:16:44,144 --> 00:16:47,273 after the explosion known as the Big Bang. 147 00:16:50,285 --> 00:16:52,345 One of them outlines the theory. 148 00:16:53,256 --> 00:16:54,814 Welcome to Fermilab. 149 00:16:55,158 --> 00:16:57,889 Today, astronomers see the universe expanding. 150 00:16:58,028 --> 00:17:00,463 lmagine running the expansion backwards. 151 00:17:00,632 --> 00:17:02,099 Billions of years ago 152 00:17:02,167 --> 00:17:05,467 everything must've been packed together at enormous density. 153 00:17:05,570 --> 00:17:06,800 lt seems incredible 154 00:17:06,906 --> 00:17:08,534 but we think that the matter 155 00:17:08,642 --> 00:17:12,079 making up everything we see in the universe 156 00:17:12,480 --> 00:17:16,474 the buildings, trees, people, planets 157 00:17:16,720 --> 00:17:19,314 stars out to the most distant galaxies 158 00:17:19,924 --> 00:17:23,917 was once crammed together into a volume smaller than this. 159 00:17:24,829 --> 00:17:26,058 And then. 160 00:17:42,185 --> 00:17:45,986 Space itself exploded, in a burst of radiant energy. 161 00:17:48,260 --> 00:17:50,524 ln those first dazzling moments 162 00:17:50,796 --> 00:17:54,734 the newborn universe began to expand and cool. 163 00:17:56,137 --> 00:17:58,834 Quarks combined into protons and neutrons 164 00:17:59,474 --> 00:18:02,774 which later attracted electrons to form atoms 165 00:18:03,746 --> 00:18:06,477 and the vast fog lifted. 166 00:18:21,035 --> 00:18:22,970 For hundreds of millions of years 167 00:18:23,038 --> 00:18:27,066 the force of gravities slowly drew matter together into a gigantic web. 168 00:18:27,944 --> 00:18:30,311 The architecture of the cosmos. 169 00:18:36,789 --> 00:18:38,757 Two billion years passed 170 00:18:39,727 --> 00:18:43,596 clouds of gas and dust condensed like giant water drops 171 00:18:43,665 --> 00:18:46,658 along the cosmic strands and formed galaxies. 172 00:18:59,952 --> 00:19:02,251 Where the great ridges of matter crossed 173 00:19:02,322 --> 00:19:04,723 galaxies came together in clusters. 174 00:19:30,124 --> 00:19:33,026 Some galaxies evolved into gigantic discs 175 00:19:33,395 --> 00:19:36,092 and spirals of stars, gas, and dust. 176 00:19:37,934 --> 00:19:40,870 Neighboring galaxies trapped by their mutual gravity 177 00:19:41,372 --> 00:19:44,171 draw together in the fantastic collision. 178 00:19:45,478 --> 00:19:48,311 ln real time, it would last a billion years. 179 00:20:27,365 --> 00:20:30,995 The force of gravities stretch long tails of gas and stars 180 00:20:31,103 --> 00:20:32,934 from the huge new galaxy. 181 00:20:36,076 --> 00:20:38,136 And yet stars almost never collide 182 00:20:39,247 --> 00:20:41,614 so vast are the distances between them. 183 00:20:52,063 --> 00:20:54,258 Perhaps ten billion years pass 184 00:20:54,967 --> 00:20:57,128 and we encounter our own galaxy: 185 00:20:57,303 --> 00:20:58,703 The Milky Way. 186 00:20:59,706 --> 00:21:01,834 ln it, stars have formed 187 00:21:02,944 --> 00:21:04,673 and some have died. 188 00:21:09,719 --> 00:21:12,280 Stars are nuclear furnaces. 189 00:21:12,490 --> 00:21:14,981 They shine until they use up their fuel. 190 00:21:15,359 --> 00:21:17,988 Massive stars end explosively. 191 00:21:32,682 --> 00:21:35,709 These exploding stars, or supernovas 192 00:21:36,521 --> 00:21:38,580 send out the elements of life: 193 00:21:38,957 --> 00:21:42,359 The oxygen we breathe, the carbon in our muscles 194 00:21:42,461 --> 00:21:44,191 the iron in our blood. 195 00:21:45,599 --> 00:21:47,568 Now a cloud of cosmic gas 196 00:21:47,802 --> 00:21:51,398 sprinkled with these elements, comes together in the grip of gravity. 197 00:21:57,348 --> 00:22:00,613 A new star, our sun, ignites. 198 00:22:03,722 --> 00:22:05,714 Around it, planets form. 199 00:22:08,595 --> 00:22:12,259 ln their infancy, over four billion years ago 200 00:22:12,767 --> 00:22:15,669 our Earth and moon were bombarded constantly 201 00:22:15,738 --> 00:22:18,105 by cosmic dust, asteroids 202 00:22:19,476 --> 00:22:20,704 and comets. 203 00:23:16,315 --> 00:23:19,615 With violent impacts and volcanic gases 204 00:23:19,820 --> 00:23:23,882 acid rain, and potent ultraviolet radiation from the sun 205 00:23:24,660 --> 00:23:27,220 the young Earth was a very hostile world. 206 00:23:30,800 --> 00:23:34,670 And yet the basic ingredients of life are already here. 207 00:23:41,949 --> 00:23:42,938 Water 208 00:23:43,784 --> 00:23:44,945 carbon 209 00:23:45,754 --> 00:23:47,312 and energy. 210 00:23:50,626 --> 00:23:54,996 Molecules, sheltered by the sea, somehow combined 211 00:23:55,098 --> 00:23:58,000 multiplied, and gave rise to life. 212 00:23:58,436 --> 00:24:03,102 For millions of years, Earth's only organisms were tiny bacteria. 213 00:24:03,743 --> 00:24:07,009 Some, called blue-green bacteria 214 00:24:07,181 --> 00:24:10,481 slowly released tiny bubbles of oxygen 215 00:24:11,019 --> 00:24:14,581 and profoundly changed the atmosphere. 216 00:24:16,693 --> 00:24:21,859 Above the clouds, some of this oxygen formed a thin layer of ozone 217 00:24:22,133 --> 00:24:25,626 blocking most of the sun's ultraviolet rays. 218 00:24:30,978 --> 00:24:33,378 ln this changed environment 219 00:24:33,649 --> 00:24:36,550 new organisms flourished in the Earth's waters. 220 00:24:38,121 --> 00:24:41,649 Colonies of green algae produced more oxygen. 221 00:24:50,002 --> 00:24:53,962 Then, organisms evolved in an astonishing variety of forms. 222 00:24:55,810 --> 00:24:59,975 Some with shells or skeletons for protection and support. 223 00:25:10,028 --> 00:25:14,989 Others evolved complex life cycles, like this tiny crustacean. 224 00:25:16,437 --> 00:25:21,535 The shallow waters of the seas filled with a teaming diversity of life forms. 225 00:25:34,727 --> 00:25:39,428 Life's next challenge was to colonize the harsh, dry land. 226 00:25:42,938 --> 00:25:47,899 Bacteria were first, followed by algae, plants, and animals. 227 00:26:13,376 --> 00:26:17,872 Vertebrates appeared on land, feeding on both plants and animals 228 00:26:19,585 --> 00:26:23,249 and gave rise to larger and larger life forms. 229 00:26:26,860 --> 00:26:29,421 Some of them conquered the realm of the air 230 00:26:30,632 --> 00:26:33,727 and others, the great open plains. 231 00:26:54,196 --> 00:26:58,099 Our cosmic voyage, from the Big Bang to the appearance of humans 232 00:26:58,167 --> 00:27:01,194 took about 15 billion years. 233 00:27:03,008 --> 00:27:05,772 From the beginning, we were explorers 234 00:27:06,345 --> 00:27:09,212 inventors and technicians. 235 00:27:17,860 --> 00:27:22,230 And in a few thousand years, just an instant in cosmic time 236 00:27:22,699 --> 00:27:27,570 curiosity and technology would take us back toward the stars. 237 00:27:57,744 --> 00:27:59,906 Since it was launched into orbit 238 00:28:00,081 --> 00:28:02,778 the Hubble space telescope has captured images 239 00:28:02,851 --> 00:28:05,081 that reveal ever more beautiful 240 00:28:05,154 --> 00:28:09,421 and mysterious regions of the universe, where stars are dying out. 241 00:28:13,898 --> 00:28:15,799 And within the Eagle Nebula 242 00:28:15,968 --> 00:28:20,269 strange towers of glowing gas are giving birth to new stars. 243 00:28:22,543 --> 00:28:24,534 ln the great Orion Nebula 244 00:28:24,612 --> 00:28:29,745 discs of dust seem to be turning into solar systems just like our own. 245 00:28:33,691 --> 00:28:37,958 The grand adventure of cosmic exploration is accelerating rapidly 246 00:28:38,196 --> 00:28:42,065 taking us into realms that once were the stuff of science fiction 247 00:28:42,402 --> 00:28:45,338 like the mysterious black hole. 248 00:28:50,846 --> 00:28:55,045 Here, a red giant star is slowly being consumed 249 00:28:55,218 --> 00:28:58,916 its gases swirling into the depths of a black hole. 250 00:29:03,595 --> 00:29:07,931 Some black holes may be collapsed cores of very massive stars 251 00:29:08,302 --> 00:29:12,467 with gravity so powerful not even light can escape them. 252 00:29:13,008 --> 00:29:17,469 But they can be detected from their trap and swallow nearby stars. 253 00:29:27,393 --> 00:29:29,555 For the first time in our history 254 00:29:29,629 --> 00:29:34,158 we now have strong evidence that there are planets orbiting other stars. 255 00:29:35,904 --> 00:29:40,365 Scientists think there could be millions of earth-like planets in our galaxy alone. 256 00:29:44,615 --> 00:29:47,710 lf so, do any of them have life? 257 00:29:52,592 --> 00:29:54,788 Some radio telescopes search for signals 258 00:29:54,895 --> 00:29:58,127 that may reveal the presence of alien civilizations. 259 00:29:59,802 --> 00:30:01,292 lt's a daunting task. 260 00:30:02,071 --> 00:30:05,166 But, if one day we should receive a signal 261 00:30:05,709 --> 00:30:08,645 it would forever change our view of ourselves 262 00:30:09,313 --> 00:30:10,975 and our universe. 263 00:30:36,315 --> 00:30:40,252 Telescopes, such as the giant Keck Observatory in Hawaii 264 00:30:40,487 --> 00:30:43,651 are like time machines capturing the faint light 265 00:30:43,724 --> 00:30:47,161 that has traveled towards us through all of cosmic history. 266 00:30:48,030 --> 00:30:52,969 The deeper astronomers look into space, the farther back they see in time. 267 00:31:09,425 --> 00:31:11,757 The more we learn about the universe 268 00:31:12,294 --> 00:31:14,627 the more new mysteries we uncover 269 00:31:15,165 --> 00:31:20,264 profound questions for future generations of cosmic explorers. 270 00:31:23,977 --> 00:31:27,345 Will the universe go on expanding forever? 271 00:31:28,182 --> 00:31:30,617 Exactly how did life arise? 272 00:31:31,553 --> 00:31:35,115 Could there be other universes beyond our cosmic horizon? 273 00:31:35,925 --> 00:31:38,895 And are there others elsewhere in the universe 274 00:31:39,096 --> 00:31:40,997 asking the same things? 275 00:31:41,799 --> 00:31:45,236 Even to ask such questions is ambitious. 276 00:31:45,971 --> 00:31:49,305 But look how far we've traveled since our ancestors 277 00:31:49,376 --> 00:31:52,869 took the first steps in our cosmic voyage. 278 00:33:30,038 --> 00:33:34,635 Man must understand his universe in order to understand his destiny. 279 00:33:35,980 --> 00:33:39,678 Who knows what mysteries will be solved in our lifetime 280 00:33:40,051 --> 00:33:44,352 and what new riddles will become the challenge of the new generations?