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These are the user uploaded subtitles that are being translated: 1 00:00:01,981 --> 00:00:05,930 This is Big Bear Lake in California, USA. 2 00:00:11,720 --> 00:00:14,969 An observatory stands in the middle of the lake. 3 00:00:17,121 --> 00:00:20,373 It houses the largest solar telescope in the world, 4 00:00:20,561 --> 00:00:22,913 completed in 2011. 5 00:00:25,373 --> 00:00:28,779 When the sun surface is observed through this telescope, 6 00:00:31,046 --> 00:00:33,616 a strange pattern can be seen. 7 00:00:33,951 --> 00:00:36,024 The heat generated within is making the gas 8 00:00:36,025 --> 00:00:39,059 on the surface bubble up and boil. 9 00:00:43,600 --> 00:00:47,165 This is the sun as seen from space by a satellite. 10 00:00:51,622 --> 00:00:55,331 With surface temperatures exceeding 6,000 degrees Celsius, 11 00:00:55,332 --> 00:00:57,269 the sun glows red hot. 12 00:01:00,178 --> 00:01:03,897 The dark shadows that can be seen are called sunspots. 13 00:01:04,061 --> 00:01:06,543 Violent explosions occur around these spots 14 00:01:06,544 --> 00:01:08,174 from time to time. 15 00:01:14,444 --> 00:01:18,178 This erupting loop of gas is known as a prominence. 16 00:01:18,436 --> 00:01:21,281 At 15 times the size of the Earth, 17 00:01:21,282 --> 00:01:24,001 it is of a magnitude hard to fathom. 18 00:01:29,752 --> 00:01:32,870 It's thanks to the light and heat emitted by the sun 19 00:01:32,871 --> 00:01:34,905 that life on Earth can thrive. 20 00:01:43,314 --> 00:01:45,907 However, experts believe the sun is undergoing 21 00:01:45,908 --> 00:01:48,366 some unusual changes. 22 00:01:49,711 --> 00:01:53,213 Up to now, changes in the intensity of the suns activity 23 00:01:53,214 --> 00:01:55,903 have occurred in regular cycles. 24 00:01:56,535 --> 00:01:58,791 However, the cycles are beginning to lose 25 00:01:58,792 --> 00:02:00,959 their clockwork regularity. 26 00:02:05,736 --> 00:02:09,290 This change comes at a golden age for solar observation, 27 00:02:09,483 --> 00:02:11,898 with several satellites currently watching the sun 28 00:02:11,899 --> 00:02:13,383 from space. 29 00:02:17,958 --> 00:02:21,317 Now scientists have reached a surprising conclusion. 30 00:02:21,725 --> 00:02:24,319 They say that some time in the near future, 31 00:02:24,320 --> 00:02:27,020 the temperature of the Earth may drop. 32 00:02:31,999 --> 00:02:34,810 What is now happening to the sun 33 00:02:36,805 --> 00:02:39,734 and how will this effect life on Earth? 34 00:02:44,684 --> 00:02:47,053 Cosmic Front delves into the mystery 35 00:02:47,054 --> 00:02:49,978 of how our sun is changing. 36 00:03:57,532 --> 00:04:00,747 Coming up, going into close loop control in LSPU. 37 00:04:00,748 --> 00:04:02,505 The field of solar observation 38 00:04:02,506 --> 00:04:05,761 is entering an unprecedented golden age. 39 00:04:08,098 --> 00:04:10,757 In the last decade, countries around the world 40 00:04:10,758 --> 00:04:13,059 have launched solar observation satellites 41 00:04:13,060 --> 00:04:14,854 one after another. 42 00:04:23,464 --> 00:04:26,145 There are now more satellites than ever observing the sun 43 00:04:26,146 --> 00:04:29,943 from space, with six currently in orbit. 44 00:04:34,027 --> 00:04:37,156 The footage captured by the satellites is sent here 45 00:04:37,157 --> 00:04:41,197 to the Solar and Astrophysics laboratory in California. 46 00:04:43,398 --> 00:04:46,051 The laboratory has been developing solar observation 47 00:04:46,052 --> 00:04:48,858 satellites since the 1970s. 48 00:04:51,226 --> 00:04:54,468 This is the laborites imaging server room. 49 00:04:58,648 --> 00:05:00,766 The images captured by five of the satellites 50 00:05:00,767 --> 00:05:03,890 are collated here, and then sent out to researchers 51 00:05:03,891 --> 00:05:05,840 around the world. 52 00:05:14,301 --> 00:05:17,672 Dr. Ted Tarbell has spent the last 30 years researching 53 00:05:17,673 --> 00:05:20,723 the sun using satellite observations. 54 00:05:23,061 --> 00:05:29,648 Today we have SDO, Hinode, Stereo, and SOHO. 55 00:05:31,021 --> 00:05:33,414 As the fixed star closest to the Earth 56 00:05:33,415 --> 00:05:35,709 the sun has always been of particular interest 57 00:05:35,710 --> 00:05:37,650 to astronomers. 58 00:05:41,946 --> 00:05:44,568 Of the satellites currently observing the sun, 59 00:05:44,569 --> 00:05:47,356 the newest is SDO, which was launched 60 00:05:47,357 --> 00:05:49,959 in February 2010. 61 00:05:55,366 --> 00:05:58,221 The satellite can observe the sun in its entirety 62 00:05:58,222 --> 00:06:01,501 in both visible and ultraviolet light. 63 00:06:02,934 --> 00:06:05,118 When observed in various types of light, 64 00:06:05,119 --> 00:06:08,305 the sun appears in totally different guises. 65 00:06:17,869 --> 00:06:21,701 In normal light, the sunspots appear as small dots, 66 00:06:23,220 --> 00:06:25,696 but when seen in ultraviolet light, 67 00:06:29,248 --> 00:06:32,325 in stark contrast to the quiet, still image, 68 00:06:32,557 --> 00:06:36,421 the sun appears as a glowing orb of swirling activity. 69 00:06:41,056 --> 00:06:43,930 Sunspots are where the activity on the sun's surface 70 00:06:43,931 --> 00:06:46,079 is at the most intense. 71 00:06:46,080 --> 00:06:49,572 It follows, therefore, that the more sunspots there are, 72 00:06:49,573 --> 00:06:51,879 the more active the sun is. 73 00:06:57,221 --> 00:07:00,114 Hinode was launched in 2006. 74 00:07:00,783 --> 00:07:02,879 Its on board telescope boasts images 75 00:07:02,880 --> 00:07:05,414 of unprecedented resolution. 76 00:07:11,717 --> 00:07:14,950 What do sunspots look like under Hinode's gaze? 77 00:07:22,014 --> 00:07:24,623 What looks simply like a dot 78 00:07:27,306 --> 00:07:30,446 now looks like a moving, living organism. 79 00:07:33,232 --> 00:07:36,904 This sunspot is known among researchers as Nippon, 80 00:07:36,905 --> 00:07:39,522 as it resembles the islands of Japan. 81 00:07:45,739 --> 00:07:48,330 Thanks to the clarity of Hinode's images, 82 00:07:48,331 --> 00:07:50,925 various phenomenon have been revealed to be occurring 83 00:07:50,926 --> 00:07:52,743 around the sunspots. 84 00:07:56,688 --> 00:08:00,112 This sunspot is 20,000 kilometers wide. 85 00:08:00,516 --> 00:08:04,129 Flames reaching 10,000 degrees Celsius erupt and flicker 86 00:08:04,130 --> 00:08:05,621 around the sunspot. 87 00:08:12,005 --> 00:08:15,950 The dark ring that frames the sunspot is called a penumbra. 88 00:08:22,979 --> 00:08:25,917 When closely examined, the stripes of the penumbra 89 00:08:25,918 --> 00:08:29,853 can be seen to flow alternately in opposite directions. 90 00:08:30,488 --> 00:08:33,790 The lighter stripes flow towards the sunspot center, 91 00:08:33,934 --> 00:08:36,516 while the darker parts flow out. 92 00:08:45,750 --> 00:08:49,222 Professor Saku Tsuneta heads up an observation project 93 00:08:49,223 --> 00:08:50,998 that uses Hinode. 94 00:08:51,320 --> 00:08:54,552 He spent 11 years developing the satellite. 95 00:08:58,304 --> 00:09:00,839 He says he will never forget the first image 96 00:09:00,840 --> 00:09:02,902 sent from Hinode. 97 00:09:24,245 --> 00:09:26,248 In April 2008, 98 00:09:26,249 --> 00:09:29,687 Hinode captured the greatest explosion in the solar system. 99 00:09:32,354 --> 00:09:34,463 Between the two black sunspots 100 00:09:34,464 --> 00:09:37,779 small sparks of light start to appear until 101 00:09:41,349 --> 00:09:44,325 a band of white light suddenly erupts. 102 00:09:44,976 --> 00:09:48,741 This is a massive explosion known as a solar flare. 103 00:09:49,179 --> 00:09:51,533 The phenomenal amount of energy it emits 104 00:09:51,534 --> 00:09:55,041 is equivalent to 100 million hydrogen bombs. 105 00:10:00,412 --> 00:10:03,748 Furthermore, a strange phenomenon was also observed 106 00:10:03,749 --> 00:10:07,440 where swirls of gas were sucked into the sunspots. 107 00:10:17,931 --> 00:10:21,239 Sunspots do not necessarily stay in the same place. 108 00:10:21,515 --> 00:10:23,564 They can appear and disappear 109 00:10:23,565 --> 00:10:25,746 and are constantly changing. 110 00:10:32,689 --> 00:10:34,699 This footage shows the surface of the sun 111 00:10:34,700 --> 00:10:38,715 captured repeatedly over a period of more than 10 years. 112 00:10:39,313 --> 00:10:42,273 The lighter, glowing patches are the sunspots. 113 00:10:47,210 --> 00:10:48,918 When observed over several years, 114 00:10:48,919 --> 00:10:51,055 it becomes evident that the number of sunspots 115 00:10:51,056 --> 00:10:52,965 varies with time. 116 00:10:52,966 --> 00:10:56,687 This is proof that the sun's activity changes in intensity. 117 00:11:04,466 --> 00:11:08,188 For a long time, the fluctuations in the number of sunspots 118 00:11:08,189 --> 00:11:10,559 and therefore the level of solar activity, 119 00:11:10,560 --> 00:11:13,364 occurred in fixed 11 year cycles. 120 00:11:19,294 --> 00:11:21,789 The sun, however, is now facing a change 121 00:11:21,790 --> 00:11:23,855 in its patterns of activity. 122 00:12:08,630 --> 00:12:10,634 Having hither two marked regular cycles 123 00:12:10,635 --> 00:12:14,328 of 11 years, the sun was due for a peak in activity 124 00:12:14,329 --> 00:12:16,038 in 2011. 125 00:12:18,642 --> 00:12:20,662 However, the number of sunspots is yet 126 00:12:20,663 --> 00:12:23,104 to noticeably increase. 127 00:12:23,284 --> 00:12:27,373 In short, the suns regular cycles have started to go awry. 128 00:12:33,078 --> 00:12:35,152 And it's believed this sudden change 129 00:12:35,153 --> 00:12:38,026 may have a major impact on Earth. 130 00:12:39,959 --> 00:12:42,638 The first person to ever record sunspots 131 00:12:42,639 --> 00:12:44,878 was Galileo Galilei. 132 00:12:45,265 --> 00:12:48,427 These are sunspots sketched by Galileo. 133 00:12:49,095 --> 00:12:51,774 In the 400 years since, the number of sunspots 134 00:12:51,775 --> 00:12:53,929 has continued to be observed. 135 00:12:57,541 --> 00:13:00,807 Looking at the records, there's a period of 70 years 136 00:13:00,808 --> 00:13:03,107 when there were no sunspots. 137 00:13:06,039 --> 00:13:09,138 This period is known as the Maunder Minimum, 138 00:13:09,139 --> 00:13:11,871 named after the man who made the discovery. 139 00:13:13,841 --> 00:13:17,214 How did this period of no sunspots and low solar activity 140 00:13:17,215 --> 00:13:19,021 effect life on Earth? 141 00:13:24,651 --> 00:13:27,266 It's impossible to know at first hand how things were 142 00:13:27,267 --> 00:13:31,718 at the time, but clues can be found in an unexpected place. 143 00:13:34,111 --> 00:13:37,492 This is Kyoto, the ancient capital of Japan. 144 00:13:41,817 --> 00:13:44,898 Dr. Yasuyuki Aono is an associate professor 145 00:13:44,899 --> 00:13:47,559 at Osaka Prefecture University. 146 00:13:50,930 --> 00:13:54,158 He has come to the Yomei Bunko Library. 147 00:13:58,879 --> 00:14:01,675 It is here that he read some ancient texts 148 00:14:01,676 --> 00:14:05,351 passed down through the Konoe family of court nobility. 149 00:14:22,463 --> 00:14:24,572 The timing of when cherry trees bloom 150 00:14:24,573 --> 00:14:28,493 is determined by the temperatures at the start of Spring. 151 00:14:31,447 --> 00:14:34,609 With this in mind, Aono looked for diary entries 152 00:14:34,610 --> 00:14:38,249 that would provide clues to the temperatures at the time. 153 00:15:00,387 --> 00:15:03,453 The research showed that in the early 1600s 154 00:15:03,454 --> 00:15:06,850 cherry trees were in full bloom about 100 days 155 00:15:06,851 --> 00:15:08,686 after January 1st. 156 00:15:11,272 --> 00:15:13,323 But by the late 1600s, 157 00:15:13,324 --> 00:15:16,342 the day of full bloom came more than 10 days later 158 00:15:16,343 --> 00:15:17,468 than this. 159 00:15:21,156 --> 00:15:24,731 Using this data, Aono was able to compute the temperatures 160 00:15:24,732 --> 00:15:25,928 at the time. 161 00:15:29,292 --> 00:15:31,956 This showed that during the 70 year Maunder Minimum 162 00:15:31,957 --> 00:15:34,450 period, the average temperatures were nearly 163 00:15:34,451 --> 00:15:36,268 two degrees lower. 164 00:15:41,955 --> 00:15:45,794 During the period of low solar activity and fewer sunspots, 165 00:15:45,795 --> 00:15:49,118 it is thought that Kyoto went through a cooling phase. 166 00:15:52,079 --> 00:15:55,149 In fact, Japan was not the only place that experienced 167 00:15:55,150 --> 00:15:56,502 cooling. 168 00:15:59,441 --> 00:16:02,471 The River Thames flows through the center of London. 169 00:16:08,550 --> 00:16:10,815 This painting from the late 1600s 170 00:16:10,816 --> 00:16:13,470 shows a frozen Thames. 171 00:16:15,253 --> 00:16:18,276 During this time, poor crop harvests were recorded 172 00:16:18,277 --> 00:16:19,821 across Europe. 173 00:16:24,301 --> 00:16:27,171 The Maunder Minimum, when sunspots disappeared 174 00:16:27,172 --> 00:16:29,197 and solar activity plummeted, 175 00:16:29,198 --> 00:16:31,701 was a period of global cooling. 176 00:16:38,499 --> 00:16:41,342 The Earth is warmed by the sun's light. 177 00:16:41,343 --> 00:16:44,848 When sunspots were scarce and activity levels low, 178 00:16:44,849 --> 00:16:47,675 how much weaker was the sun's light? 179 00:16:52,653 --> 00:16:54,905 An American solar observation satellite 180 00:16:54,906 --> 00:16:57,023 has been making accurate measurements 181 00:16:57,024 --> 00:16:59,594 of the levels of light given off by the sun 182 00:16:59,595 --> 00:17:01,716 for more then 40 years. 183 00:17:06,288 --> 00:17:08,333 These are the results. 184 00:17:08,334 --> 00:17:10,666 What is surprising is that whether the sun is 185 00:17:10,667 --> 00:17:13,683 at its most active with lots of sunspots 186 00:17:13,684 --> 00:17:16,236 or whether its activity levels and number of sunspots 187 00:17:16,237 --> 00:17:17,682 are low, 188 00:17:18,547 --> 00:17:23,547 the level of light it emits varies by a mere 0.15%. 189 00:17:24,851 --> 00:17:27,211 It is practically constant. 190 00:17:30,595 --> 00:17:33,572 But if the levels of light from the sun did not decrease 191 00:17:33,573 --> 00:17:36,113 during this period of fewer sunspots, 192 00:17:36,271 --> 00:17:38,931 why then did the Earth's temperature drop? 193 00:17:46,923 --> 00:17:50,689 The answer lies not in the sun's light, but elsewhere. 194 00:17:58,690 --> 00:18:01,731 Big Bear Lake in California, USA. 195 00:18:08,714 --> 00:18:11,811 A narrow road stretches out into the lake. 196 00:18:15,201 --> 00:18:17,484 A white dome stands at the end of it 197 00:18:17,485 --> 00:18:19,979 as if it's floating on the water. 198 00:18:21,709 --> 00:18:24,844 This is Big Bear Solar Observatory, 199 00:18:24,845 --> 00:18:27,869 operated by the New Jersey Institute of Technology. 200 00:18:32,413 --> 00:18:36,314 The observatory was rebuilt in February 2010. 201 00:18:41,367 --> 00:18:44,472 It houses the world's largest solar telescope. 202 00:18:54,575 --> 00:18:58,123 Professor Phil Goode is the director of the observatory. 203 00:18:58,383 --> 00:19:01,848 He has spent the past 40 years studying the sun. 204 00:19:04,856 --> 00:19:06,419 Good, good. 205 00:19:11,107 --> 00:19:12,982 This is the observatory's state of the art 206 00:19:12,983 --> 00:19:14,559 telescope. 207 00:19:16,259 --> 00:19:18,664 It stands eight meters high. 208 00:19:19,790 --> 00:19:21,552 It is painted white all over 209 00:19:21,553 --> 00:19:24,145 so as not to absorb the sun's heat. 210 00:19:26,885 --> 00:19:30,162 This mirror is the largest aperture mirror 211 00:19:30,163 --> 00:19:32,154 for any solar telescope in the world 212 00:19:32,155 --> 00:19:35,282 and makes it the most powerful solar telescope. 213 00:19:36,455 --> 00:19:39,180 Collecting the light coming in from the dome window 214 00:19:39,181 --> 00:19:42,340 is a 1.5 meter wide reflecting mirror. 215 00:19:53,930 --> 00:19:56,146 Compared to artificial satellites, 216 00:19:56,147 --> 00:19:58,584 the advantage of ground-based observation 217 00:19:58,585 --> 00:20:02,011 is that large telescopes like this can be used. 218 00:20:06,451 --> 00:20:08,333 The major disadvantage, however, 219 00:20:08,334 --> 00:20:10,519 is the presence of air. 220 00:20:15,851 --> 00:20:17,821 The turbulence in the heated up air 221 00:20:17,822 --> 00:20:20,535 causes the images to be blurred. 222 00:20:22,534 --> 00:20:25,065 There are two ways in which the observatory combats 223 00:20:25,066 --> 00:20:26,997 this problem. 224 00:20:27,339 --> 00:20:29,820 Three kilometers of open water to the West 225 00:20:29,821 --> 00:20:32,168 and so we have nice, smooth air 226 00:20:32,169 --> 00:20:35,460 coming in and that enables us to correct our images 227 00:20:35,461 --> 00:20:38,213 with adaptive optics all day long. 228 00:20:40,505 --> 00:20:42,611 By placing the telescope on water, 229 00:20:42,612 --> 00:20:45,429 which is less likely to warm up than the ground, 230 00:20:45,430 --> 00:20:49,030 there is less turbulence in the air around the observatory. 231 00:20:53,249 --> 00:20:56,080 The second way to solve the problem can be found in the room 232 00:20:56,081 --> 00:20:59,509 where the light gathered by the telescope is analyzed. 233 00:21:03,035 --> 00:21:06,528 An observation room lies directly under the telescope. 234 00:21:07,179 --> 00:21:09,635 The light from the sun captured by the telescope 235 00:21:09,636 --> 00:21:12,054 is guided down from the ceiling. 236 00:21:13,650 --> 00:21:16,635 The light passes through several mirrors and lenses 237 00:21:16,636 --> 00:21:18,871 into the observation equipment. 238 00:21:22,182 --> 00:21:24,343 The mirror in the middle is specially designed 239 00:21:24,344 --> 00:21:26,945 to minimize the atmospheric distortion. 240 00:21:30,067 --> 00:21:33,515 Amazingly, it can change shape in an instant. 241 00:21:36,987 --> 00:21:39,968 A high speed camera detects turbulence in the air 242 00:21:39,969 --> 00:21:41,883 which prompts the mirror to change shape 243 00:21:41,884 --> 00:21:44,292 in order to correct any distortion, 244 00:21:44,293 --> 00:21:46,866 producing a pristine image. 245 00:21:47,167 --> 00:21:51,199 This special technology is called adaptive optics. 246 00:21:55,314 --> 00:21:57,502 Here is how the technology works. 247 00:22:02,874 --> 00:22:06,257 A 30,000 kilometer square area of the sun's surface 248 00:22:06,258 --> 00:22:07,804 is magnified. 249 00:22:11,885 --> 00:22:15,114 It shows hot gas bubbling up from the interior. 250 00:22:15,555 --> 00:22:17,127 The image is in focus, 251 00:22:17,128 --> 00:22:20,274 but because of the turbulence in the air, it is blurred. 252 00:22:22,339 --> 00:22:25,881 This is where the adaptive optics equipment comes into play. 253 00:22:29,704 --> 00:22:33,093 At once, a crystal clear image is revealed. 254 00:22:41,316 --> 00:22:43,915 The telescope can be employed to observe the sun 255 00:22:43,916 --> 00:22:47,751 using a special type of light known as H-Alpha. 256 00:22:52,455 --> 00:22:54,892 Several curved lines can be seen. 257 00:22:58,815 --> 00:23:01,851 This in fact shows the source of the sun's activity. 258 00:23:04,285 --> 00:23:07,248 These curved lines may look strangely familiar. 259 00:23:10,298 --> 00:23:13,092 They are identical to the magnetic field lines 260 00:23:13,093 --> 00:23:16,604 that appear when iron filings are poured over a magnet. 261 00:23:19,443 --> 00:23:22,444 The curved lines show that there is magnetism everywhere 262 00:23:22,445 --> 00:23:24,400 around the sun. 263 00:23:25,575 --> 00:23:31,412 Those jets are plasma that's excited and sent up 264 00:23:31,413 --> 00:23:33,753 and attracts along magnetic field lines, 265 00:23:33,754 --> 00:23:35,595 so you can see an outline 266 00:23:35,596 --> 00:23:37,651 of the magnetic field of the sun 267 00:23:37,652 --> 00:23:40,984 and on the smallest scale, it's everywhere. 268 00:23:41,252 --> 00:23:43,114 So that's a surprise. 269 00:23:43,115 --> 00:23:45,899 The sun is truly a magnetic star. 270 00:23:47,206 --> 00:23:50,172 The sun is covered in magnetism. 271 00:23:50,619 --> 00:23:53,242 The surface may appear quiet and still, 272 00:23:53,243 --> 00:23:56,760 yet it's 100 times more magnetic than the Earth. 273 00:23:57,446 --> 00:23:59,949 Where the intensely active sunspots lie, 274 00:23:59,950 --> 00:24:02,912 it can be as much as 10,000 times more. 275 00:24:07,066 --> 00:24:09,608 The sun is covered all over by distinctive loops 276 00:24:09,609 --> 00:24:13,531 of magnetic field lines produced by the strong magnetism. 277 00:24:16,820 --> 00:24:20,040 This magnetism is generated in the sun's interior. 278 00:24:25,034 --> 00:24:27,682 There is a 400,000 kilometer deep layer 279 00:24:27,683 --> 00:24:29,627 under the surface of the sun 280 00:24:29,628 --> 00:24:33,110 where hot gases circulate in convection currents. 281 00:24:35,814 --> 00:24:37,451 It is thought that the sun's magnetism 282 00:24:37,452 --> 00:24:40,733 is generated by the energy of the moving gases 283 00:24:40,734 --> 00:24:42,611 at the bottom of this layer. 284 00:24:48,624 --> 00:24:51,775 The sun's magnetism can be seen in its full glory 285 00:24:51,776 --> 00:24:54,043 during a total solar eclipse. 286 00:24:58,048 --> 00:25:00,570 The sun's atmosphere, called the corona, 287 00:25:00,571 --> 00:25:03,017 only appears at the moment the moon obscures 288 00:25:03,018 --> 00:25:05,520 the intensely bright sun. 289 00:25:06,876 --> 00:25:10,424 Examined closely, a streaky pattern can be seen. 290 00:25:11,151 --> 00:25:14,444 These streaks are the magnetic field lines that the sun, 291 00:25:14,445 --> 00:25:17,832 the magnetic star, emits into space. 292 00:25:21,890 --> 00:25:24,997 It is this magnetism that causes the various phenomena 293 00:25:24,998 --> 00:25:26,464 on the sun. 294 00:25:28,537 --> 00:25:30,875 The flames that flicker on the surface of the sun 295 00:25:30,876 --> 00:25:32,732 are prominences. 296 00:25:36,743 --> 00:25:39,400 These prominences are eruptions of gas 297 00:25:39,401 --> 00:25:41,387 caused by magnetism. 298 00:25:46,628 --> 00:25:50,616 This phenomenon can be recreated using a magnetic toy. 299 00:25:52,490 --> 00:25:55,461 When a magnetic top is spun on top of a stand, 300 00:25:55,462 --> 00:25:58,552 the magnetism causes the top to float in the air. 301 00:26:03,587 --> 00:26:06,413 Similarly, prominences are plasma gases 302 00:26:06,414 --> 00:26:10,021 that float up through the power of the sun's magnetic force. 303 00:26:19,618 --> 00:26:22,680 Solar flares are the largest explosive events 304 00:26:22,681 --> 00:26:24,829 in our solar system. 305 00:26:26,247 --> 00:26:30,133 They are also caused by the sun's strong magnetic force. 306 00:26:31,789 --> 00:26:34,674 Magnetic field lines shoot out from inside the sun 307 00:26:34,675 --> 00:26:36,711 onto the surface. 308 00:26:36,712 --> 00:26:38,903 When the lines are pulled together at their base 309 00:26:38,904 --> 00:26:40,743 by convection currents, 310 00:26:40,744 --> 00:26:43,312 the two sets of lines connect. 311 00:26:43,845 --> 00:26:47,506 At this point, the magnetic field lines recombine. 312 00:26:48,532 --> 00:26:50,827 The newly reconnected lines contract 313 00:26:50,828 --> 00:26:52,667 like an elastic band. 314 00:26:55,240 --> 00:26:58,718 They snap back and force gas down onto the surface 315 00:26:58,719 --> 00:27:02,726 of the sun, leading to a violent explosion. 316 00:27:05,776 --> 00:27:08,042 The intense activity seen on the sun 317 00:27:08,043 --> 00:27:10,559 is the product of the massive magnetic energy 318 00:27:10,560 --> 00:27:13,802 that is constantly generated inside the star. 319 00:27:17,740 --> 00:27:22,330 In fact, the sun's strong magnetic field extends so far 320 00:27:22,331 --> 00:27:25,036 that it envelopes the whole solar system. 321 00:27:31,887 --> 00:27:35,172 This magnetism lies at the root of the various activities 322 00:27:35,173 --> 00:27:37,278 seen on the sun's surface. 323 00:27:47,021 --> 00:27:49,832 The Earth, too, has a magnetic field. 324 00:27:50,092 --> 00:27:53,273 It's field lines extend neatly from North to South. 325 00:27:56,535 --> 00:27:59,390 In the sun's case, however, the magnetic field lines 326 00:27:59,391 --> 00:28:01,988 are arranged in a complex tangle. 327 00:28:06,187 --> 00:28:08,562 The sun's secret lies here. 328 00:28:12,662 --> 00:28:14,899 The sun rotates on its own axis 329 00:28:14,900 --> 00:28:17,589 once every 27 days or so. 330 00:28:18,102 --> 00:28:19,742 Being made up of gas, 331 00:28:19,743 --> 00:28:22,196 it's rotational speed can vary. 332 00:28:22,474 --> 00:28:24,896 It rotates faster near the equator 333 00:28:24,897 --> 00:28:27,338 and more slowly at its poles. 334 00:28:31,466 --> 00:28:33,356 This means that the magnetic field lines 335 00:28:33,357 --> 00:28:36,410 that run from North to South in its interior 336 00:28:36,411 --> 00:28:38,792 are gradually pulled sideways 337 00:28:38,793 --> 00:28:41,151 and end up wrapped around the sun. 338 00:28:49,664 --> 00:28:52,679 The magnetic field lines vary in density 339 00:28:52,680 --> 00:28:56,089 and where they are lighter, they float up to the surface. 340 00:28:58,174 --> 00:29:00,235 When these field lines break through, 341 00:29:00,236 --> 00:29:02,512 they form sunspots. 342 00:29:04,611 --> 00:29:07,361 Sunspots are areas where the strong magnetic force 343 00:29:07,362 --> 00:29:11,084 created inside the sun shoots out of the surface. 344 00:29:16,956 --> 00:29:20,177 What happens then to the strength of the magnetic force 345 00:29:20,178 --> 00:29:22,981 when there are changes in the suns activity? 346 00:29:25,959 --> 00:29:29,718 As previously seen, light levels stay fairly constant 347 00:29:29,719 --> 00:29:32,163 even with changes in number of sunspots 348 00:29:32,164 --> 00:29:34,544 and levels of solar activity. 349 00:29:35,789 --> 00:29:38,531 Here, the strength of the suns magnetic force 350 00:29:38,532 --> 00:29:40,958 is added to the graph. 351 00:29:41,720 --> 00:29:44,640 The magnetic force varies greatly. 352 00:29:45,306 --> 00:29:47,793 Furthermore, the changes correlate perfectly 353 00:29:47,794 --> 00:29:50,313 with the levels of solar activity. 354 00:29:55,815 --> 00:29:58,364 The sun's magnetic force fluctuates wildly 355 00:29:58,365 --> 00:30:01,442 with the changes in solar activity levels. 356 00:30:02,940 --> 00:30:06,310 A hitherto unimagined possibility has emerged 357 00:30:06,311 --> 00:30:08,910 that it is in fact this magnetic force 358 00:30:08,911 --> 00:30:10,642 that has a major influence 359 00:30:10,643 --> 00:30:13,037 on the Earth's changing temperature. 360 00:30:17,591 --> 00:30:19,383 In the late 1600s. 361 00:30:19,384 --> 00:30:22,865 When sunspots disappeared and solar activity dropped, 362 00:30:22,976 --> 00:30:25,844 the Earth experienced global cooling. 363 00:30:30,975 --> 00:30:33,044 Why did the Earth's temperature fall 364 00:30:33,045 --> 00:30:35,406 when solar activity levels decreased 365 00:30:35,407 --> 00:30:38,562 and the sun's magnetic force weakened? 366 00:30:43,493 --> 00:30:46,844 In 1997, a paper written in Denmark 367 00:30:46,845 --> 00:30:49,289 caused shockwaves around the world. 368 00:30:54,652 --> 00:30:57,494 It claimed that the sun's magnetic force 369 00:30:57,495 --> 00:30:59,561 effects the Earth's clouds. 370 00:31:06,548 --> 00:31:09,808 The author of the paper lives in Denmark. 371 00:31:15,033 --> 00:31:16,850 Yes, hello. 372 00:31:16,851 --> 00:31:18,667 Professor Henrik Svensmark 373 00:31:18,668 --> 00:31:21,091 is based at the National Space Institute, 374 00:31:21,092 --> 00:31:24,351 otherwise known as DTU Space. 375 00:31:25,738 --> 00:31:27,212 Since publishing his paper 376 00:31:27,213 --> 00:31:30,153 Svensmark has continued to research the relationship 377 00:31:30,154 --> 00:31:32,913 between the sun and the Earth's climate. 378 00:31:35,762 --> 00:31:37,391 This is 379 00:31:37,871 --> 00:31:40,633 what we call our sky experiment. 380 00:31:40,883 --> 00:31:42,633 We are testing 381 00:31:43,063 --> 00:31:45,356 how clouds are 382 00:31:45,725 --> 00:31:47,965 forming or some of the processes that are important 383 00:31:47,966 --> 00:31:50,019 for cloud formation. 384 00:31:50,842 --> 00:31:52,976 Svensmark noticed a strong correlation 385 00:31:52,977 --> 00:31:56,592 between cloud cover and something rather unexpected. 386 00:32:00,274 --> 00:32:02,455 This graph shows levels of cloud cover 387 00:32:02,456 --> 00:32:04,310 as measured by satellites. 388 00:32:06,766 --> 00:32:08,637 Svensmark discovered something else 389 00:32:08,638 --> 00:32:12,446 that fluctuates in the same way as levels of cloud cover. 390 00:32:13,004 --> 00:32:15,040 It was cosmic rays, 391 00:32:15,041 --> 00:32:18,075 the radiation that showers down from space. 392 00:32:21,841 --> 00:32:25,793 Cosmic rays are a type of radiation generated in outer space 393 00:32:25,794 --> 00:32:29,410 when a star reaches the end of its life and explodes. 394 00:32:32,944 --> 00:32:35,892 Some of the rays travel across space over a long period 395 00:32:35,893 --> 00:32:38,342 of time and reach Earth. 396 00:32:40,931 --> 00:32:44,068 Svensmark noticed that when there are more cosmic rays, 397 00:32:44,069 --> 00:32:46,888 the Earth's cloud cover increases 398 00:32:46,889 --> 00:32:51,159 and when cosmic rays decrease, cloud cover falls. 399 00:32:54,676 --> 00:32:56,235 That is 400 00:32:56,723 --> 00:32:58,773 you know, it's a big surprise, 401 00:32:58,774 --> 00:33:01,855 and the agreement was 402 00:33:02,512 --> 00:33:05,650 fairly good even though it was very a short period 403 00:33:05,651 --> 00:33:06,819 that we had data. 404 00:33:06,820 --> 00:33:08,054 The agreement was very good, 405 00:33:08,055 --> 00:33:11,654 but the mere idea that there could be such a connection 406 00:33:11,812 --> 00:33:13,832 I thought was very 407 00:33:14,557 --> 00:33:16,002 exciting. 408 00:33:17,972 --> 00:33:19,168 Up until then, 409 00:33:19,169 --> 00:33:21,425 no one had ever imagined a relationship 410 00:33:21,426 --> 00:33:24,789 between cloud formation and cosmic rays. 411 00:33:29,433 --> 00:33:31,729 This idea first occurred to Svensmark 412 00:33:31,730 --> 00:33:33,729 when he thought of an experiment he had seen 413 00:33:33,730 --> 00:33:35,642 at high school. 414 00:33:38,517 --> 00:33:40,104 Of course, the cloud chamber at that time 415 00:33:40,105 --> 00:33:41,531 was much, much smaller, 416 00:33:41,532 --> 00:33:43,367 but it's the same principle. 417 00:33:43,368 --> 00:33:44,939 It works fine. 418 00:33:46,414 --> 00:33:48,294 This is a cloud chamber, 419 00:33:48,295 --> 00:33:50,550 an apparatus filled with vapor. 420 00:33:53,265 --> 00:33:55,090 There's one there. 421 00:33:55,091 --> 00:33:57,928 But it lasts only maybe a second 422 00:33:58,520 --> 00:34:00,439 and then it's gone. 423 00:34:01,548 --> 00:34:04,798 From time to time, white streaks appear. 424 00:34:05,149 --> 00:34:08,174 These streaks are the tracks of the cosmic rays 425 00:34:08,175 --> 00:34:10,865 that fall onto Earth from space. 426 00:34:13,778 --> 00:34:16,349 When cosmic rays pass through the vapor, 427 00:34:16,350 --> 00:34:18,535 cloud-like forms appear. 428 00:34:26,058 --> 00:34:27,742 I thought immediately that 429 00:34:27,743 --> 00:34:30,270 if cosmic rays are important, 430 00:34:31,995 --> 00:34:33,436 it might be clouds. 431 00:34:33,437 --> 00:34:36,476 Sorry, yes, it might be clouds that they are 432 00:34:36,477 --> 00:34:38,726 effecting, so that was the basic idea. 433 00:34:40,781 --> 00:34:42,833 Svensmark believes that the cosmic rays 434 00:34:42,834 --> 00:34:46,304 that fall from afar cause clouds to form. 435 00:34:50,705 --> 00:34:53,321 It is widely known that the sun's magnetic force 436 00:34:53,322 --> 00:34:56,456 effects the levels of galactic cosmic rays. 437 00:35:03,824 --> 00:35:06,694 Cosmic rays fly down towards Earth. 438 00:35:07,160 --> 00:35:09,464 The suns strong magnetic field, however, 439 00:35:09,465 --> 00:35:12,399 extends all the way across the solar system. 440 00:35:12,776 --> 00:35:16,433 This acts as a barrier, making it difficult for cosmic rays 441 00:35:16,434 --> 00:35:17,996 to break through. 442 00:35:22,098 --> 00:35:24,476 But when solar activity levels drop, 443 00:35:24,477 --> 00:35:26,501 the magnetic shield weakens 444 00:35:26,502 --> 00:35:29,848 allowing more cosmic rays to enter the solar system. 445 00:35:32,360 --> 00:35:35,407 The cosmic rays can then reach the Earth's atmosphere. 446 00:35:37,841 --> 00:35:41,146 In short, the volume of cosmic rays that reaches Earth 447 00:35:41,147 --> 00:35:44,064 is determined by solar activity levels. 448 00:35:47,059 --> 00:35:51,273 Here, solar activity levels are added to the earlier graph. 449 00:35:53,312 --> 00:35:56,073 It is evident that when solar activity is low 450 00:35:56,074 --> 00:35:58,090 and the magnetic shield weakened, 451 00:35:58,091 --> 00:36:00,321 more cosmic rays fall on Earth 452 00:36:00,322 --> 00:36:02,541 and there is greater cloud coverage. 453 00:36:07,875 --> 00:36:11,175 What is important is the sun's magnetic field, 454 00:36:11,600 --> 00:36:13,357 which shields against the cosmic rays 455 00:36:13,358 --> 00:36:15,505 and when this shield changes, 456 00:36:15,681 --> 00:36:18,036 it changes the Earth's cloudiness 457 00:36:18,260 --> 00:36:21,356 and thereby the temperature of the Earth. 458 00:36:21,594 --> 00:36:24,198 So the solar activity 459 00:36:24,465 --> 00:36:26,836 and the plasma that comes from the sun 460 00:36:26,837 --> 00:36:28,363 or the magnetic field 461 00:36:28,364 --> 00:36:31,333 is really what controls the climate. 462 00:36:33,955 --> 00:36:37,159 Clouds are not formed by water vapor alone. 463 00:36:38,616 --> 00:36:41,915 They can only form with the presence of tiny particles 464 00:36:41,916 --> 00:36:45,496 that act as seeds around which water vapor gathers. 465 00:36:49,571 --> 00:36:52,523 In this photo taken above the Pacific Ocean, 466 00:36:52,524 --> 00:36:54,275 white streaks can be seen. 467 00:36:57,048 --> 00:36:59,548 These are clouds created by ships 468 00:36:59,549 --> 00:37:01,872 travelling across the ocean. 469 00:37:02,243 --> 00:37:05,271 Water vapor gathers around the tiny particles 470 00:37:05,272 --> 00:37:08,896 found in the ships exhaust forming clouds. 471 00:37:14,166 --> 00:37:16,625 Svensmark theorizes that cosmic rays 472 00:37:16,626 --> 00:37:19,129 effect the formation of these particles. 473 00:37:21,449 --> 00:37:23,449 When cosmic rays reach Earth, 474 00:37:23,450 --> 00:37:26,275 they collide with molecules in the air. 475 00:37:26,947 --> 00:37:29,998 The molecules then become charged with electricity 476 00:37:29,999 --> 00:37:31,833 and are drawn to each other 477 00:37:31,834 --> 00:37:34,006 growing bigger and bigger. 478 00:37:37,112 --> 00:37:39,745 This gives rise to the tiny particles necessary 479 00:37:39,746 --> 00:37:41,798 in cloud formation. 480 00:37:43,273 --> 00:37:44,752 According to this theory, 481 00:37:44,753 --> 00:37:47,052 the particles become cloud seeds 482 00:37:47,053 --> 00:37:49,527 for water vapor to gather around 483 00:37:49,528 --> 00:37:51,860 and clouds are formed. 484 00:37:57,371 --> 00:37:59,876 Svensmark's theory of climate change on Earth 485 00:37:59,877 --> 00:38:01,991 can be summarized thus: 486 00:38:03,133 --> 00:38:06,496 The Earth is protected by the sun's magnetic field, 487 00:38:06,497 --> 00:38:09,576 but when this is weakened, higher levels of cosmic rays 488 00:38:09,577 --> 00:38:11,348 can reach Earth. 489 00:38:11,349 --> 00:38:14,216 This creates more particles up in the air 490 00:38:14,494 --> 00:38:16,673 giving rise to clouds. 491 00:38:19,593 --> 00:38:22,077 As a result, sunlight is blocked, 492 00:38:22,078 --> 00:38:24,038 and the Earth cools. 493 00:38:24,938 --> 00:38:27,794 What is happening in the space surrounding us 494 00:38:27,795 --> 00:38:32,945 is very important and the solar activity can change 495 00:38:32,946 --> 00:38:35,552 the number of particles which changes the cloudiness 496 00:38:35,553 --> 00:38:37,655 of the Earth, which changes the climate. 497 00:38:37,656 --> 00:38:39,352 So that is the 498 00:38:39,816 --> 00:38:42,709 connection that it's very surprising, 499 00:38:42,710 --> 00:38:46,053 but that is how things look now. 500 00:38:49,113 --> 00:38:51,237 Svensmark's claim that the Earth's climate 501 00:38:51,238 --> 00:38:55,590 is influenced by space sparked a heated debate worldwide. 502 00:38:59,885 --> 00:39:03,325 His theory is now being verified around the world. 503 00:39:09,399 --> 00:39:11,755 The most extensive verification of the theory 504 00:39:11,756 --> 00:39:15,732 is being carried out just outside Geneva in Switzerland 505 00:39:15,733 --> 00:39:19,025 at the European Organization for Nuclear Research 506 00:39:19,026 --> 00:39:20,903 known as CERN. 507 00:39:21,980 --> 00:39:24,912 Large-scale research, such as studies into the origins 508 00:39:24,913 --> 00:39:28,251 of the universe, is being carried out using the world's 509 00:39:28,252 --> 00:39:30,513 largest particle accelerator, 510 00:39:30,514 --> 00:39:32,892 which is 27 kilometers long. 511 00:39:38,836 --> 00:39:40,932 One of the projects being carried out here 512 00:39:40,933 --> 00:39:42,720 is the cloud experiment, 513 00:39:42,721 --> 00:39:45,988 which investigates the relationship between cosmic rays 514 00:39:45,989 --> 00:39:47,395 and clouds. 515 00:39:49,322 --> 00:39:52,643 Consisting of an airtight chamber three meters in diameter 516 00:39:52,644 --> 00:39:56,399 and four meters high, it is the only facility in the world 517 00:39:56,400 --> 00:39:59,094 which can recreate the conditions of the atmosphere 518 00:39:59,095 --> 00:40:01,032 anywhere on Earth. 519 00:40:01,033 --> 00:40:04,133 Using this, scientists can test whether cosmic rays 520 00:40:04,134 --> 00:40:06,624 really do cause clouds. 521 00:40:08,565 --> 00:40:10,434 So this is the 522 00:40:11,071 --> 00:40:13,189 cloud chamber where we 523 00:40:13,582 --> 00:40:15,187 create the atmosphere 524 00:40:15,188 --> 00:40:19,511 and investigate the effective cosmic rays from the beam 525 00:40:20,223 --> 00:40:22,574 on the cloud processes. 526 00:40:25,259 --> 00:40:27,757 Dr. Jasper Kirkby uses this chamber 527 00:40:27,758 --> 00:40:30,173 to run the cloud experiment. 528 00:40:30,174 --> 00:40:32,429 He started the project three years ago 529 00:40:32,430 --> 00:40:35,430 as a result of Svensmark's research. 530 00:40:42,957 --> 00:40:45,467 26,000 liters of air can be trapped 531 00:40:45,468 --> 00:40:47,778 inside this airtight chamber. 532 00:40:52,320 --> 00:40:55,020 The ceiling is fitted with lights that irradiate the same 533 00:40:55,021 --> 00:40:58,700 strong ultraviolet light that comes down from the sky. 534 00:41:01,959 --> 00:41:05,011 The experiment simulates the composition of the air, 535 00:41:05,012 --> 00:41:08,021 the temperatures, humidity, and light levels 536 00:41:08,022 --> 00:41:10,592 to recreate the exact same conditions 537 00:41:10,593 --> 00:41:13,480 as the atmosphere where clouds are formed. 538 00:41:15,910 --> 00:41:18,690 The chamber is then showered with cosmic rays 539 00:41:18,691 --> 00:41:21,318 artificially created by the accelerator. 540 00:41:24,041 --> 00:41:27,128 The researchers then carefully check for the tiny particles 541 00:41:27,129 --> 00:41:29,675 necessary for cloud formation. 542 00:41:36,050 --> 00:41:38,512 The results can be seen here. 543 00:41:41,391 --> 00:41:44,777 When the chamber is irradiated with artificial cosmic rays 544 00:41:44,778 --> 00:41:47,323 from the large-scale accelerator, 545 00:41:47,975 --> 00:41:50,222 the chamber quickly begins to fill up 546 00:41:50,223 --> 00:41:52,137 with tiny particles. 547 00:41:58,264 --> 00:42:00,034 When these particles grow, 548 00:42:00,035 --> 00:42:03,274 they form the seeds that give rise to clouds. 549 00:42:04,538 --> 00:42:07,679 We've run for three so-called campaigns 550 00:42:07,680 --> 00:42:09,468 and we're finiding a very strong effect 551 00:42:09,469 --> 00:42:11,900 when the beam goes through the chamber, 552 00:42:11,901 --> 00:42:14,343 these particles, these seeds, 553 00:42:14,773 --> 00:42:17,636 for cloud droplets or at least the embryonic form, 554 00:42:17,637 --> 00:42:22,001 the very small version of them, do form 555 00:42:22,002 --> 00:42:25,031 much more abundantly when the beam goes through. 556 00:42:27,169 --> 00:42:28,627 Furthermore, it has been found 557 00:42:28,628 --> 00:42:31,846 that when the number of tiny particles increases 558 00:42:31,847 --> 00:42:34,909 the nature of the clouds themselves changes. 559 00:42:39,472 --> 00:42:42,972 Research has been carried out using Japan's earth simulator 560 00:42:42,973 --> 00:42:44,586 super computer. 561 00:42:53,850 --> 00:42:57,228 Professor Kanya Kusano of Nagoya University 562 00:42:57,229 --> 00:43:00,054 studied the effect the number of tiny particles has 563 00:43:00,055 --> 00:43:01,546 on cloud formation 564 00:43:01,547 --> 00:43:04,037 when the amount of water vapor is fixed. 565 00:43:07,912 --> 00:43:09,445 In this simulation, 566 00:43:09,446 --> 00:43:12,724 air containing water vapor is warmed up on the ground 567 00:43:12,725 --> 00:43:14,165 and rises. 568 00:43:19,779 --> 00:43:22,595 The water vapor gathers together up in the air 569 00:43:22,596 --> 00:43:24,815 and forms clouds. 570 00:43:25,379 --> 00:43:28,321 In time, rain falls from the clouds 571 00:43:28,322 --> 00:43:30,785 and the clouds disappear. 572 00:43:32,639 --> 00:43:35,619 The number of tiny particles that form the cloud seeds 573 00:43:35,620 --> 00:43:37,245 is then varied. 574 00:43:40,860 --> 00:43:43,283 When there are fewer tiny particles, 575 00:43:43,284 --> 00:43:46,672 the water vapor that rises does form clouds, 576 00:43:46,957 --> 00:43:50,815 but it quickly leads to rainfall and the clouds disperse. 577 00:43:53,876 --> 00:43:56,332 With a large number of tiny particles, however, 578 00:43:56,333 --> 00:43:58,601 there is hardly any rainfall 579 00:43:58,602 --> 00:44:00,923 and the clouds remain for longer. 580 00:44:03,823 --> 00:44:07,441 Kusano has a theory of what causes this difference. 581 00:44:09,039 --> 00:44:11,989 The amount of water vapor is kept constant. 582 00:44:11,990 --> 00:44:14,377 When there are fewer tiny particles, 583 00:44:14,378 --> 00:44:17,330 more water is concentrated on each particle 584 00:44:17,331 --> 00:44:20,572 creating big droplets that fall as rain. 585 00:44:22,314 --> 00:44:24,572 With lots of tiny particles, however, 586 00:44:24,573 --> 00:44:27,064 each particle attracts less water 587 00:44:27,065 --> 00:44:29,770 creating droplets that are too small and light 588 00:44:29,771 --> 00:44:31,451 to fall as rain. 589 00:44:36,547 --> 00:44:38,215 The number of tiny particles 590 00:44:38,216 --> 00:44:41,014 determines whether the droplets turn into rain 591 00:44:41,015 --> 00:44:43,104 or stay as clouds, 592 00:44:44,511 --> 00:44:47,678 and this has major repercussions on the amount of light 593 00:44:47,679 --> 00:44:49,723 that reaches Earth. 594 00:44:53,974 --> 00:44:55,878 When solar activity drops 595 00:44:55,879 --> 00:44:58,321 and the suns magnetic field weakens 596 00:44:58,322 --> 00:45:00,270 more clouds are formed, 597 00:45:00,271 --> 00:45:03,259 which may lead to a cooling of the Earth. 598 00:45:06,784 --> 00:45:10,398 Will the present lowering of solar activity levels continue 599 00:45:10,855 --> 00:45:13,571 or will it return to previous levels? 600 00:45:18,849 --> 00:45:22,386 Researchers are looking to the past for clues to the future. 601 00:45:22,815 --> 00:45:24,481 The island of Yakushima, 602 00:45:24,482 --> 00:45:27,814 a natural world heritage site, offers an answer. 603 00:45:31,775 --> 00:45:33,480 Dr. Hiroko Miyahara from the 604 00:45:33,481 --> 00:45:37,170 University of Tokyo's Institute for Cosmic Ray Research 605 00:45:37,171 --> 00:45:40,063 is investigating trends in solar activity levels 606 00:45:40,064 --> 00:45:42,171 from the past thousand years. 607 00:45:44,176 --> 00:45:47,132 She's here to study the Yakusugi cedar trees 608 00:45:47,133 --> 00:45:49,658 aged 1,000 years or more. 609 00:45:52,207 --> 00:45:55,242 A growth ring sample from a fallen Yakusugi tree 610 00:45:55,243 --> 00:45:57,411 is carefully extracted. 611 00:46:16,498 --> 00:46:18,718 This sample contains a special substance 612 00:46:18,719 --> 00:46:20,638 that provides valuable clues 613 00:46:20,639 --> 00:46:23,171 to the sun's activity in the past. 614 00:46:23,609 --> 00:46:25,824 That substance is carbon. 615 00:46:29,285 --> 00:46:31,687 When cosmic rays hit the atmosphere, 616 00:46:31,688 --> 00:46:34,924 carbon dioxide containing a special kind of carbon, 617 00:46:34,925 --> 00:46:38,795 called C-14, is produced in varying amounts 618 00:46:38,796 --> 00:46:41,529 depending on the number of cosmic rays. 619 00:46:41,530 --> 00:46:44,682 The Yakusugi trees absorb this carbon dioxide 620 00:46:44,683 --> 00:46:46,958 through photosynthesis. 621 00:46:48,600 --> 00:46:51,310 As a result, in the years when the Earth's atmosphere 622 00:46:51,311 --> 00:46:53,881 saw a high volume of cosmic rays, 623 00:46:54,103 --> 00:46:58,103 the growth rings contain a greater quantity of C-14. 624 00:47:00,484 --> 00:47:03,338 This means that by measuring the quantity of C-14 625 00:47:03,339 --> 00:47:06,127 in each growth ring, the amount of cosmic rays 626 00:47:06,128 --> 00:47:09,290 that fell on Earth that year can be ascertained. 627 00:47:13,751 --> 00:47:16,715 Miyahara carefully peeled apart each growth ring 628 00:47:16,716 --> 00:47:20,294 of the Yakusugi and collected around 1,000 years 629 00:47:20,295 --> 00:47:21,919 worth of samples. 630 00:47:24,220 --> 00:47:26,918 By looking at the changes in volume of cosmic rays 631 00:47:26,919 --> 00:47:28,988 over 1,000 years, 632 00:47:28,989 --> 00:47:32,657 she can calculate the solar activity level of each year. 633 00:47:33,390 --> 00:47:35,421 She also noticed something interesting 634 00:47:35,422 --> 00:47:37,172 before the Maunder Minimum. 635 00:47:41,627 --> 00:47:43,999 That was the period in the 1600s 636 00:47:44,000 --> 00:47:47,133 of low solar activity and global cooling. 637 00:47:50,798 --> 00:47:53,750 It has been discovered that immediately prior to this 638 00:47:53,751 --> 00:47:56,000 the sun's cycle was 13 years 639 00:47:56,001 --> 00:47:58,143 instead of the usual 11. 640 00:48:01,395 --> 00:48:04,622 Furthermore, there have been dips in solar activity levels 641 00:48:04,623 --> 00:48:07,632 three times in the past 1,000 years, 642 00:48:07,633 --> 00:48:11,301 and before each one, the sun's cycle had lengthened. 643 00:48:13,995 --> 00:48:16,969 In other words, a pattern emerged where each time 644 00:48:16,970 --> 00:48:20,483 the sun cycle lengthens, a period of several decades 645 00:48:20,484 --> 00:48:23,297 of low solar activity follows. 646 00:48:39,840 --> 00:48:42,188 Nobody even knows what the 647 00:48:42,189 --> 00:48:44,181 upcoming solar maximum's going to look like 648 00:48:44,182 --> 00:48:48,349 or when it will be, so everything is a surprise. 649 00:48:48,350 --> 00:48:52,203 So you need to have as many eyes on the sun as possible. 650 00:49:03,892 --> 00:49:06,047 The importance of solar observation 651 00:49:06,048 --> 00:49:08,227 is greater than ever before. 652 00:49:13,041 --> 00:49:15,489 In the U.S., a mission is being planned 653 00:49:15,490 --> 00:49:19,188 to send a solar probe directly into the sun's atmosphere. 654 00:49:23,397 --> 00:49:25,921 In Japan, too, preparations are under way 655 00:49:25,922 --> 00:49:30,315 to launch another solar observation satellite in 2018. 656 00:49:31,347 --> 00:49:34,658 At the National Astronomical Observatory of Japan, 657 00:49:34,659 --> 00:49:37,489 Professor Tsuneta of the Hinode project 658 00:49:37,490 --> 00:49:40,640 is leading the development of this new satellite. 659 00:50:03,434 --> 00:50:05,169 And I think the sun 660 00:50:05,170 --> 00:50:09,030 is very likely having a very strong effect on our climate, 661 00:50:09,031 --> 00:50:11,081 but we don't understand it scientifically. 662 00:50:11,082 --> 00:50:13,557 So I think it's our duty as scientists, all of us, 663 00:50:13,558 --> 00:50:16,284 the climate scientists, the solar scientists, 664 00:50:16,492 --> 00:50:18,458 satellite, physics, everybody 665 00:50:18,459 --> 00:50:21,541 to really pull their capabilities 666 00:50:21,542 --> 00:50:23,684 and understand our star, 667 00:50:23,685 --> 00:50:25,404 which is controlling our lives. 668 00:50:28,111 --> 00:50:31,148 The sun is mother of all life on Earth. 669 00:50:36,342 --> 00:50:38,761 Scientists around the world are researching 670 00:50:38,762 --> 00:50:40,688 what will happen to Earth 671 00:50:40,689 --> 00:50:43,358 when the sun's activity falls. 672 00:50:47,501 --> 00:50:50,925 What they discover will have important repercussions 673 00:50:50,926 --> 00:50:53,854 for all of us here on Earth. 52925

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