1 00:00:01,968 --> 00:00:05,927 Imagine if you could halt the constant march of time. 2 00:00:11,611 --> 00:00:15,206 ...if you could slow it down... and speed it up. 3 00:00:17,517 --> 00:00:21,647 Imagine if you could stop time... or even reverse it. 4 00:00:23,857 --> 00:00:26,792 The world about us would look quite different. 5 00:00:31,097 --> 00:00:36,626 Imagine no longer... come with us as we go on a journey through time. 6 00:00:55,155 --> 00:00:57,783 Our lives are ruled by the clock. 7 00:01:03,863 --> 00:01:05,626 But our obsession with time 8 00:01:05,799 --> 00:01:07,824 should come as no surprise. 9 00:01:08,501 --> 00:01:10,867 Deep inside us we all have a clock 10 00:01:11,037 --> 00:01:13,130 that regulates our lives. 11 00:01:17,477 --> 00:01:19,104 Can this body clock tell us 12 00:01:19,279 --> 00:01:21,543 when we're most likely to get drunk? 13 00:01:26,920 --> 00:01:31,152 If we all wanted to live forever could this worm 14 00:01:31,324 --> 00:01:33,588 hold the key to eternal life? 15 00:01:39,966 --> 00:01:41,092 In our busy lives 16 00:01:41,267 --> 00:01:43,667 we are always chasing time 17 00:01:43,903 --> 00:01:45,200 always trying to save it. 18 00:01:46,005 --> 00:01:49,031 But in a crisis how can we change time 19 00:01:49,209 --> 00:01:51,234 to help save ourselves? 20 00:01:58,885 --> 00:02:01,877 We think of ourselves as slaves to the clock. 21 00:02:11,831 --> 00:02:14,061 Racing through life at breakneck speed, 22 00:02:14,234 --> 00:02:15,599 has become the norm. 23 00:02:20,840 --> 00:02:23,400 But could our pursuit of speed 24 00:02:23,576 --> 00:02:25,703 be the key to time travel, 25 00:02:25,879 --> 00:02:28,370 letting us visit the distant future? 26 00:02:31,184 --> 00:02:35,348 Will we ever truly become masters of time? 27 00:02:45,832 --> 00:02:47,663 Time is precious. 28 00:02:47,867 --> 00:02:49,767 We never seem to have enough. 29 00:02:54,974 --> 00:02:57,442 We've spent centuries building clocks, 30 00:02:57,610 --> 00:02:59,635 all to more and more accurately 31 00:02:59,812 --> 00:03:03,680 measure the passing of hours, minutes and seconds. 32 00:03:03,850 --> 00:03:06,683 Yet it still doesn't buy us any more of the stuff. 33 00:03:09,322 --> 00:03:12,689 Time has come to mean the straitjacketing of our day - 34 00:03:12,926 --> 00:03:14,587 the constant schedule 35 00:03:14,761 --> 00:03:16,456 that rules our lives. 36 00:03:20,300 --> 00:03:21,767 Yet, if you think about it, 37 00:03:21,935 --> 00:03:24,267 our everyday experience of time 38 00:03:24,437 --> 00:03:25,699 is far from constant. 39 00:03:27,307 --> 00:03:29,366 We all have long, lazy days 40 00:03:29,542 --> 00:03:32,033 when time seems to stand still. 41 00:03:35,715 --> 00:03:37,444 But time doesn't change, 42 00:03:37,617 --> 00:03:39,084 only our sense of it. 43 00:03:39,285 --> 00:03:41,048 This sensation might all be down 44 00:03:41,221 --> 00:03:43,382 to how we process what we see. 45 00:03:45,658 --> 00:03:47,626 We can see the effect at the movies. 46 00:03:47,794 --> 00:03:50,854 A film seems to pass by in a seamless flow. 47 00:03:53,132 --> 00:03:54,861 But what we are really seeing 48 00:03:55,034 --> 00:03:57,332 is a series of static photographs, 49 00:03:57,503 --> 00:03:59,971 one following quickly after another. 50 00:04:03,209 --> 00:04:04,141 When slowed down it's clear 51 00:04:04,310 --> 00:04:07,211 that each one is slightly different from the one before. 52 00:04:07,380 --> 00:04:10,076 Flash twenty-four of them past each second, 53 00:04:10,250 --> 00:04:13,014 and they create a sense of fluid movement. 54 00:04:18,958 --> 00:04:21,153 Your brain works in a similar way. 55 00:04:24,097 --> 00:04:25,257 When you leave the cinema 56 00:04:25,431 --> 00:04:26,762 you're also seeing the world 57 00:04:26,933 --> 00:04:28,958 as a series of pictures. 58 00:04:36,876 --> 00:04:40,209 Your brain does a rapid scan of each new image 59 00:04:40,380 --> 00:04:41,870 to register what's changed. 60 00:04:42,048 --> 00:04:42,844 It's how we avoid 61 00:04:43,016 --> 00:04:43,948 bumping into things. 62 00:04:44,117 --> 00:04:45,414 But, like a film, 63 00:04:45,585 --> 00:04:47,678 we just see the joined-up effect. 64 00:04:52,158 --> 00:04:55,719 If we could reduce the number of images we see each second, 65 00:04:55,895 --> 00:05:00,264 just imagine how our sense of time would change too. 66 00:05:06,639 --> 00:05:08,800 Our lives would appear to flash past 67 00:05:08,975 --> 00:05:10,340 like an express train. 68 00:05:23,122 --> 00:05:25,420 The seasons would whiz past in minutes 69 00:05:25,591 --> 00:05:26,990 rather than months. 70 00:05:36,369 --> 00:05:37,427 Lf, on the other hand, 71 00:05:37,603 --> 00:05:39,628 our brains scanned a huge number 72 00:05:39,806 --> 00:05:43,674 of separate images every second, we'd be swamped with detail. 73 00:05:43,843 --> 00:05:46,744 It would be like living in perpetual slow motion. 74 00:05:55,888 --> 00:05:57,048 And let's face it, 75 00:05:57,223 --> 00:05:59,123 that's just too chilled out. 76 00:06:02,161 --> 00:06:04,095 But not for a fly. 77 00:06:04,297 --> 00:06:08,290 A fly needs exactly this heightened level of awareness 78 00:06:08,468 --> 00:06:10,095 because it hurtles through the world 79 00:06:10,269 --> 00:06:11,998 at such high speed. 80 00:06:13,606 --> 00:06:14,868 Flies see things we don't; 81 00:06:15,041 --> 00:06:16,508 the flickering of a strip-light 82 00:06:16,676 --> 00:06:19,509 and the individual scans on a TV-screen. 83 00:06:20,980 --> 00:06:22,345 Most importantly it can see 84 00:06:22,515 --> 00:06:24,176 the need for a quick escape, 85 00:06:24,350 --> 00:06:26,443 from the fly swat, for instance. 86 00:06:31,224 --> 00:06:32,088 We don't need to see 87 00:06:32,258 --> 00:06:34,192 the world like the fly. 88 00:06:34,527 --> 00:06:38,156 Day to day that level of detail is unnecessary. 89 00:06:38,398 --> 00:06:41,094 The rate at which we clock our surroundings is the one 90 00:06:41,267 --> 00:06:43,895 that best fits our pace of life. 91 00:06:53,279 --> 00:06:54,439 It can vary. 92 00:06:54,680 --> 00:06:55,510 When we're waiting, 93 00:06:55,681 --> 00:06:57,649 time seems to drag. 94 00:06:59,185 --> 00:07:00,015 When we're busy, 95 00:07:00,186 --> 00:07:01,483 time flies. 96 00:07:03,923 --> 00:07:06,357 But we can override all of this. 97 00:07:06,526 --> 00:07:08,118 We have a remarkable, 98 00:07:08,294 --> 00:07:10,262 hidden power over time. 99 00:07:10,430 --> 00:07:11,089 It kicks 100 00:07:11,264 --> 00:07:12,663 in during a crisis. 101 00:07:17,336 --> 00:07:18,564 Faced with extreme danger 102 00:07:18,738 --> 00:07:20,672 the mind enters an altered state. 103 00:07:20,840 --> 00:07:22,967 People report seeing in black and white - 104 00:07:23,142 --> 00:07:25,770 why bother to waste time processing colour 105 00:07:25,945 --> 00:07:28,379 when your brain is on overload? 106 00:07:32,552 --> 00:07:36,545 But most importantly, people say time slows down. 107 00:07:38,291 --> 00:07:40,521 The brain is now on high alert, 108 00:07:40,693 --> 00:07:41,819 processing far more 109 00:07:41,994 --> 00:07:43,894 each second than normal. 110 00:07:49,535 --> 00:07:52,402 It buys you extra time - to think... 111 00:07:52,738 --> 00:07:53,796 and act. 112 00:08:03,282 --> 00:08:04,943 So we can, when necessary, 113 00:08:05,117 --> 00:08:07,017 and without a second thought, 114 00:08:07,186 --> 00:08:10,212 fundamentally control our experience of time. 115 00:08:10,923 --> 00:08:11,912 Why, then, do we feel 116 00:08:12,091 --> 00:08:13,991 we're such slaves to the clock? 117 00:08:24,770 --> 00:08:26,533 Time is organized to a level 118 00:08:26,706 --> 00:08:28,833 that borders on obsession. 119 00:08:29,141 --> 00:08:29,971 We can now measure it 120 00:08:30,142 --> 00:08:32,508 to the nearest billionth of a second. 121 00:08:34,380 --> 00:08:36,678 How did this obsession start? 122 00:08:43,556 --> 00:08:45,456 Well we've come by it quite naturally. 123 00:08:45,625 --> 00:08:47,593 Even though the Egyptians were the first 124 00:08:47,760 --> 00:08:50,422 to formally divide daylight into hours, 125 00:08:50,596 --> 00:08:51,790 we were well equipped 126 00:08:51,964 --> 00:08:54,159 to tell the time way before this. 127 00:08:58,371 --> 00:09:01,966 Our earliest ancestors used the changing seasons 128 00:09:02,141 --> 00:09:04,006 to measure out the years. 129 00:09:10,283 --> 00:09:13,411 The phases of the moon marked out the months. 130 00:09:16,322 --> 00:09:18,517 But it was the daily arc of the sun 131 00:09:18,691 --> 00:09:19,885 that counted most. 132 00:09:29,535 --> 00:09:31,560 Nature follows this rhythm. 133 00:09:41,647 --> 00:09:45,242 So no surprise that the sun's movement across the sky 134 00:09:45,418 --> 00:09:46,908 affects us too. 135 00:09:54,293 --> 00:09:55,419 Although we used the shadows 136 00:09:55,595 --> 00:09:57,529 it cast to mark time, 137 00:09:57,697 --> 00:10:00,894 the sun's influence goes much deeper than this. 138 00:10:04,337 --> 00:10:07,898 It helps our bodies keep time by regulating a clock 139 00:10:08,074 --> 00:10:09,974 that we don't even see. 140 00:10:15,147 --> 00:10:16,808 One that's ticking away deep 141 00:10:16,983 --> 00:10:18,348 inside us. 142 00:10:22,655 --> 00:10:24,282 It's a biological clock 143 00:10:24,457 --> 00:10:27,221 a master clock that's set by the sun 144 00:10:27,393 --> 00:10:30,419 and which controls all aspects of our lives - 145 00:10:30,596 --> 00:10:31,722 when you are most alert, 146 00:10:31,897 --> 00:10:32,864 when you sleep, 147 00:10:33,032 --> 00:10:36,399 and even when you are most likely to visit the toilet. 148 00:10:46,212 --> 00:10:48,646 The exact location of this clock? 149 00:10:49,115 --> 00:10:51,049 Right in the middle of your brain 150 00:10:51,217 --> 00:10:54,345 in an area called the hypothalamus. 151 00:10:57,289 --> 00:10:59,621 But, like man-made timepieces, 152 00:10:59,792 --> 00:11:02,727 this biological clock loses time. 153 00:11:03,029 --> 00:11:06,624 It has to be reset twice a day by the sun. 154 00:11:09,135 --> 00:11:13,697 It's all done through a hotline of nerves that link this master clock, 155 00:11:13,873 --> 00:11:16,341 via the eye, to the outside world 156 00:11:16,509 --> 00:11:18,875 and so to the sun's cycle. 157 00:11:28,120 --> 00:11:29,417 Mostly we're oblivious 158 00:11:29,588 --> 00:11:31,488 to how our bodies keep time. 159 00:11:31,724 --> 00:11:34,192 And yet we're riddled with different clocks. 160 00:11:34,427 --> 00:11:35,951 Even our liver has one. 161 00:11:36,162 --> 00:11:38,392 The liver does most of our detoxing, 162 00:11:38,564 --> 00:11:40,964 so knowing how it ticks is crucial 163 00:11:41,133 --> 00:11:42,896 if you need to stay sober, 164 00:11:43,069 --> 00:11:45,503 or if you really want to get legless. 165 00:11:49,675 --> 00:11:50,801 So what's the low-down? 166 00:11:51,210 --> 00:11:53,906 The liver is on go-slow and least able 167 00:11:54,080 --> 00:11:57,106 to break down alcohol around lunchtime - 168 00:11:57,349 --> 00:12:00,807 so drinking then will get you merrier, quicker. 169 00:12:15,334 --> 00:12:16,824 But a few too many does 170 00:12:17,002 --> 00:12:19,197 more than make you feel woozy. 171 00:12:19,438 --> 00:12:23,465 It can have some very strange effects on your other cycles. 172 00:12:26,612 --> 00:12:29,080 Your body temperature follows a very strong rhythm, 173 00:12:29,248 --> 00:12:32,149 which is also controlled by a biological clock. 174 00:12:32,685 --> 00:12:36,587 But this is knocked off track after a session at the pub. 175 00:12:38,691 --> 00:12:40,420 Using a thermal camera to monitor 176 00:12:40,593 --> 00:12:41,821 the body's temperature 177 00:12:41,994 --> 00:12:43,461 scientists can track 178 00:12:43,629 --> 00:12:46,393 how the normal rhythm is upset. 179 00:12:46,665 --> 00:12:48,633 The changing colours show the temperature 180 00:12:48,801 --> 00:12:50,894 see-sawing through the night. 181 00:13:04,083 --> 00:13:07,814 It's the disruption to this, and other body clocks, 182 00:13:07,987 --> 00:13:11,150 that's thought to affect the size of your hangover. 183 00:13:13,659 --> 00:13:17,060 But science isn't revealing all bad news. 184 00:13:18,597 --> 00:13:21,725 Just as there's the best time to drink alcohol, 185 00:13:21,901 --> 00:13:24,597 there is also a prime time to take the cure. 186 00:13:24,870 --> 00:13:26,929 The latest research shows any medicine 187 00:13:27,106 --> 00:13:28,596 will most likely work best 188 00:13:28,774 --> 00:13:31,834 if taken at a particular time of day. 189 00:13:34,680 --> 00:13:37,581 It's already known that painkillers do the job best 190 00:13:37,750 --> 00:13:38,978 when taken in the morning. 191 00:13:40,886 --> 00:13:41,750 So now you can deal 192 00:13:41,921 --> 00:13:44,617 with that hangover a bit quicker too. 193 00:13:53,899 --> 00:13:57,460 There seems to be no escape from the pressure of time. 194 00:13:57,803 --> 00:13:59,498 Our bodies are full of clocks 195 00:13:59,672 --> 00:14:01,640 regulating everything we do. 196 00:14:07,346 --> 00:14:10,076 But what we really want is more time 197 00:14:10,249 --> 00:14:11,546 and the only way to achieve 198 00:14:11,717 --> 00:14:14,743 that is to stretch the lifetime we've got. 199 00:14:28,934 --> 00:14:33,268 When our biological clock stops ticking, so do we. 200 00:14:33,472 --> 00:14:34,097 Is there anything 201 00:14:34,273 --> 00:14:36,503 we can do to keep it going? 202 00:14:38,377 --> 00:14:40,038 Scientists have always been searching 203 00:14:40,212 --> 00:14:43,545 for life's holy grail - immortality. 204 00:14:47,653 --> 00:14:50,588 But now nature is giving them some clues. 205 00:14:53,759 --> 00:14:55,317 For most living things, 206 00:14:55,494 --> 00:14:57,291 freezing is deadly. 207 00:14:57,830 --> 00:15:00,060 But insects, such as this weta, 208 00:15:00,232 --> 00:15:01,221 some amphibians, 209 00:15:01,400 --> 00:15:03,925 and even a species of reptile, 210 00:15:04,103 --> 00:15:06,833 survive months of extreme cold 211 00:15:07,006 --> 00:15:08,769 by doing just this. 212 00:15:09,108 --> 00:15:11,702 They put time on hold. 213 00:15:17,016 --> 00:15:20,782 Ice-crystals usually destroy living cells. 214 00:15:21,020 --> 00:15:22,715 But not in these animals. 215 00:15:22,888 --> 00:15:25,550 When warm weather brings a thaw, 216 00:15:25,724 --> 00:15:26,986 they're back in business. 217 00:15:33,465 --> 00:15:34,056 How they do this 218 00:15:34,233 --> 00:15:36,098 might prove useful one day, 219 00:15:36,268 --> 00:15:37,997 but some people can't wait. 220 00:15:38,404 --> 00:15:40,201 They've been frozen, 221 00:15:40,372 --> 00:15:42,533 in the belief that solutions to ageing 222 00:15:42,708 --> 00:15:45,176 and disease will be found. 223 00:15:47,913 --> 00:15:50,313 The catch is: You have to be dead first. 224 00:15:55,854 --> 00:15:57,754 After dying these optimists 225 00:15:57,923 --> 00:16:01,290 are suspended head first in liquid nitrogen 226 00:16:01,460 --> 00:16:04,861 at minus 196 degrees Centigrade. 227 00:16:05,030 --> 00:16:08,158 And there they remain, frozen in time, 228 00:16:08,334 --> 00:16:12,361 banking on a future when death can be reversed. 229 00:16:22,081 --> 00:16:23,514 Back in the real world, 230 00:16:23,682 --> 00:16:25,582 even our attempts to live longer 231 00:16:25,751 --> 00:16:27,514 are backfiring on us. 232 00:16:27,753 --> 00:16:29,778 The very air we need to breathe, 233 00:16:29,955 --> 00:16:31,422 is also killing us. 234 00:16:35,561 --> 00:16:38,394 We breathe in over 10,000 times a day 235 00:16:38,564 --> 00:16:39,622 and each time something 236 00:16:39,798 --> 00:16:42,130 in the air makes us age. 237 00:16:42,301 --> 00:16:43,359 It's oxygen. 238 00:16:48,741 --> 00:16:51,767 Our cells need oxygen to make energy, 239 00:16:51,944 --> 00:16:55,004 but leftover oxygen slips away 240 00:16:55,180 --> 00:16:58,240 and starts a kind of rusting from within. 241 00:17:01,887 --> 00:17:02,876 Oxygen isn't 242 00:17:03,055 --> 00:17:05,080 the only rogue element. 243 00:17:07,059 --> 00:17:10,085 Sunlight, pollution and tobacco smoke 244 00:17:10,262 --> 00:17:13,459 also form these so-called free radicals. 245 00:17:13,832 --> 00:17:16,960 And it's these radicals that do the damage. 246 00:17:19,104 --> 00:17:22,471 The good news is there's something that can stop the rot. 247 00:17:24,243 --> 00:17:26,370 Even though it proves your mum right. 248 00:17:27,813 --> 00:17:29,713 You have to eat your greens. 249 00:17:31,450 --> 00:17:34,544 Vegetables in particular contain antioxidants, 250 00:17:34,720 --> 00:17:37,052 which help soak up those free radicals. 251 00:17:37,222 --> 00:17:41,750 So broccoli and beans help keep those wrinkles at bay. 252 00:17:47,599 --> 00:17:49,794 If you had thought that was the bad news, 253 00:17:49,968 --> 00:17:51,697 well, there's worse. 254 00:17:51,904 --> 00:17:55,032 The human body has a design flaw. 255 00:18:00,179 --> 00:18:03,410 All the billions of cells that make up our bodies 256 00:18:03,582 --> 00:18:06,244 contain the genetic instruction manual 257 00:18:06,418 --> 00:18:07,009 that makes us who 258 00:18:07,186 --> 00:18:09,654 we are DNA. 259 00:18:10,022 --> 00:18:12,286 Our cells need constant renewal 260 00:18:12,458 --> 00:18:14,551 and they do this by dividing. 261 00:18:14,827 --> 00:18:16,624 Each time the DNA instructions 262 00:18:16,795 --> 00:18:19,025 get copied and passed on. 263 00:18:23,202 --> 00:18:26,399 Sadly the system's got a glitch and, 264 00:18:26,572 --> 00:18:28,233 surprisingly quickly, 265 00:18:28,407 --> 00:18:30,568 mistakes start creeping in. 266 00:18:33,912 --> 00:18:37,643 As the cells divide, a bit of DNA information 267 00:18:37,816 --> 00:18:39,113 might get lost. 268 00:18:39,284 --> 00:18:40,308 So the new cell isn't 269 00:18:40,486 --> 00:18:42,215 an exact copy. 270 00:18:42,387 --> 00:18:45,151 It's a bit like a game of Chinese whispers. 271 00:18:48,293 --> 00:18:49,351 It's why our bodies 272 00:18:49,528 --> 00:18:51,689 end up looking very different 273 00:18:51,864 --> 00:18:53,126 from how they started. 274 00:18:57,936 --> 00:19:00,564 Ageing seems to be a fact of life, 275 00:19:00,739 --> 00:19:03,674 so how on earth can we stay forever young? 276 00:19:07,146 --> 00:19:08,078 For starters you could try 277 00:19:08,247 --> 00:19:09,714 hiding your age. 278 00:19:09,882 --> 00:19:12,442 But even if all the surgery, creams, 279 00:19:12,618 --> 00:19:15,314 supplements and Botox in the world 280 00:19:15,487 --> 00:19:17,079 make you look younger, 281 00:19:17,422 --> 00:19:19,083 they won't help you live forever. 282 00:19:26,265 --> 00:19:30,395 Still, we are pushing our lifetime as far as we can. 283 00:19:33,038 --> 00:19:35,768 Just a century ago life expectancy in the West 284 00:19:35,941 --> 00:19:37,806 was around 40 years. 285 00:19:37,976 --> 00:19:39,341 But thanks to better diets 286 00:19:39,511 --> 00:19:41,001 and medical back up, 287 00:19:41,180 --> 00:19:45,514 a child born now can expect to live to a ripe old age of 80. 288 00:19:49,588 --> 00:19:51,112 Today in the UK 289 00:19:51,290 --> 00:19:54,316 there are more centenarians than ever before. 290 00:19:58,030 --> 00:20:02,933 In 1952 the Queen sent 225 telegrams to people 291 00:20:03,101 --> 00:20:04,864 on their 100th birthday. 292 00:20:05,304 --> 00:20:09,673 In 2003 she sent almost 5000. 293 00:20:12,244 --> 00:20:13,905 But what's our limit? 294 00:20:15,647 --> 00:20:20,516 Well we believe the oldest human ever lived to 122. 295 00:20:22,187 --> 00:20:24,519 So can we buy ourselves more time? 296 00:20:24,690 --> 00:20:26,624 Some scientists think we can. 297 00:20:29,795 --> 00:20:32,263 They've increased the life of one animal 298 00:20:32,431 --> 00:20:35,628 to the human equivalent of 500 years. 299 00:20:36,768 --> 00:20:39,396 Admittedly it's only a worm. 300 00:20:39,571 --> 00:20:42,597 But it has genes that control ageing. 301 00:20:44,710 --> 00:20:48,441 By fiddling with these genes scientists have turned the worm, 302 00:20:48,614 --> 00:20:52,414 on the right, into a very ancient specimen indeed. 303 00:20:53,819 --> 00:20:55,514 Maybe, with a similar genetic 304 00:20:55,687 --> 00:20:56,619 nip and tuck, 305 00:20:56,788 --> 00:20:58,312 we could one day cheat time 306 00:20:58,490 --> 00:21:00,458 and live much, much longer. 307 00:21:03,228 --> 00:21:05,958 But for now, perhaps the best way to buy more time 308 00:21:06,131 --> 00:21:07,393 is not with science, 309 00:21:07,566 --> 00:21:08,931 but by having fun. 310 00:21:21,280 --> 00:21:25,239 You can grow even older - by staying young at heart. 311 00:21:33,692 --> 00:21:35,159 A happy, optimistic person 312 00:21:35,327 --> 00:21:37,693 could dramatically extend their life 313 00:21:37,863 --> 00:21:39,694 by over twenty years. 314 00:21:45,037 --> 00:21:47,767 Instead of reaching just 85, 315 00:21:47,939 --> 00:21:50,999 you could laugh your way to 106. 316 00:21:54,546 --> 00:21:56,241 So, keep on smiling. 317 00:21:57,783 --> 00:22:01,310 Oh, and remember to eat those greens! 318 00:22:09,528 --> 00:22:12,190 Although our time eventually runs out, 319 00:22:12,364 --> 00:22:13,388 we're finding ways of 320 00:22:13,565 --> 00:22:16,056 pushing life spans to the limit. 321 00:22:16,435 --> 00:22:19,199 Look after your body and it will look after you. 322 00:22:19,538 --> 00:22:22,632 Our brains can change how we experience time 323 00:22:22,808 --> 00:22:24,469 and avoid disaster. 324 00:22:24,776 --> 00:22:26,767 And with a little help from the sun, 325 00:22:26,945 --> 00:22:29,914 our body clocks keep ticking over nicely. 326 00:22:30,449 --> 00:22:32,314 So without even realising, 327 00:22:32,484 --> 00:22:34,975 our bodies already master time. 328 00:22:36,988 --> 00:22:39,149 But we're not content with this. 329 00:22:39,524 --> 00:22:42,618 We expect more and more from the time we've got. 330 00:22:43,161 --> 00:22:45,925 Which means everything else has to speed up. 331 00:22:50,736 --> 00:22:53,034 How has this race against time 332 00:22:53,205 --> 00:22:55,173 changed the world around us? 333 00:23:06,752 --> 00:23:08,276 One of the biggest repercussions 334 00:23:08,453 --> 00:23:10,148 from doing things more quickly 335 00:23:10,322 --> 00:23:13,780 may have been triggered over 50,000 years ago. 336 00:23:14,126 --> 00:23:17,527 This was when man first set foot in Australia. 337 00:23:18,330 --> 00:23:19,558 The first people brought something 338 00:23:19,731 --> 00:23:21,528 that helped them to survive here, 339 00:23:21,700 --> 00:23:25,192 but it was something that may have changed the landscape forever. 340 00:23:30,275 --> 00:23:31,435 Fire. 341 00:23:40,519 --> 00:23:43,113 With fire they may have set off a chain of events 342 00:23:43,288 --> 00:23:45,017 that they knew nothing about. 343 00:23:45,624 --> 00:23:46,556 It's just one example 344 00:23:46,725 --> 00:23:48,989 of how we humans cannot see 345 00:23:49,161 --> 00:23:51,061 the results of what we do. 346 00:23:51,263 --> 00:23:53,356 Not because the events aren't dramatic, 347 00:23:53,532 --> 00:23:56,865 but because they happen on a timescale way, 348 00:23:57,035 --> 00:23:58,935 way beyond our own. 349 00:24:11,750 --> 00:24:13,547 To see what happened in Australia, 350 00:24:13,718 --> 00:24:15,652 we first have to appreciate how fire 351 00:24:15,821 --> 00:24:18,187 transformed these people's lives. 352 00:24:19,958 --> 00:24:21,482 Fire is destructive, 353 00:24:21,660 --> 00:24:24,424 so why torch the very land they lived on? 354 00:24:40,912 --> 00:24:43,107 It was all done to save time. 355 00:24:43,548 --> 00:24:47,541 With fire they could clear the land faster than ever before. 356 00:25:05,136 --> 00:25:06,831 And despite appearances 357 00:25:07,005 --> 00:25:08,768 the devastation was short lived. 358 00:25:09,074 --> 00:25:10,439 The bare ground was quickly 359 00:25:10,609 --> 00:25:12,702 filled with fresh new growth. 360 00:25:13,144 --> 00:25:16,910 These tender shoots attracted grazing animals. 361 00:25:17,148 --> 00:25:19,981 It made hunting quicker and easier. 362 00:25:26,458 --> 00:25:30,656 Saving time is all part of the human drive to survive. 363 00:25:30,962 --> 00:25:32,327 But now there's a suggestion 364 00:25:32,497 --> 00:25:34,692 that these small-scale fires 365 00:25:34,866 --> 00:25:37,460 did more than just scorch a few plants. 366 00:25:45,310 --> 00:25:46,572 Only now, with the benefit 367 00:25:46,745 --> 00:25:47,939 of hindsight, 368 00:25:48,113 --> 00:25:50,343 can we see how the dramatic changes, 369 00:25:50,515 --> 00:25:52,847 here in Australia, might have begun. 370 00:25:57,322 --> 00:25:59,882 Fire was such a great time-saver 371 00:25:59,991 --> 00:26:02,983 that the early people relied on it more and more. 372 00:26:03,395 --> 00:26:05,454 As the blazes became more frequent, 373 00:26:05,630 --> 00:26:08,929 the plants had less and less time to grow back. 374 00:26:13,104 --> 00:26:16,631 Thousands of fires over thousands of generations 375 00:26:16,808 --> 00:26:20,676 may have changed the relationship between the plants and the climate. 376 00:26:22,547 --> 00:26:27,211 Eventually some of Australia's annual monsoons just dried up. 377 00:26:34,759 --> 00:26:38,695 The skies cleared and the rivers ran dry. 378 00:27:02,187 --> 00:27:05,850 Gone was the water from in front of their eyes. 379 00:27:10,762 --> 00:27:12,957 But because it disappeared little by little, 380 00:27:13,131 --> 00:27:15,725 drop-by-drop over thousands of years, 381 00:27:15,900 --> 00:27:17,424 they never saw it happening. 382 00:27:20,939 --> 00:27:22,702 Some believed this continental-scale 383 00:27:22,874 --> 00:27:26,833 change in the weather dried up Australia's largest lake. 384 00:27:27,412 --> 00:27:28,879 When the first people arrived, 385 00:27:29,047 --> 00:27:33,245 Lake Eyre covered a vast area in the middle of the country. 386 00:27:33,551 --> 00:27:35,678 Its disappearance coincided 387 00:27:35,854 --> 00:27:37,344 with man's arrival. 388 00:27:45,797 --> 00:27:47,424 Tiny bits of timesaving 389 00:27:47,599 --> 00:27:49,226 the use of fire to clear the land 390 00:27:49,401 --> 00:27:51,562 and speed up the hunt for food 391 00:27:51,803 --> 00:27:52,531 added up, 392 00:27:52,704 --> 00:27:54,797 over time, to this. 393 00:27:55,140 --> 00:27:59,736 Australia turned into the largely desert continent we know today. 394 00:28:02,347 --> 00:28:04,815 And a once massive lake is gone. 395 00:28:24,969 --> 00:28:26,732 Fire is one of the first time 396 00:28:26,905 --> 00:28:27,963 saving devices 397 00:28:28,139 --> 00:28:30,369 but it certainly wasn't the last. 398 00:28:30,642 --> 00:28:33,634 We humans will do anything to cut corners. 399 00:28:33,945 --> 00:28:36,505 But, even as we settled into the fast lane, 400 00:28:36,681 --> 00:28:37,375 we discovered something 401 00:28:37,549 --> 00:28:39,983 that took us up a whole new gear. 402 00:29:11,116 --> 00:29:13,949 The sun once ruled our day. 403 00:29:14,252 --> 00:29:16,550 Here we're turning the sun's heat 404 00:29:16,721 --> 00:29:18,552 into round the clock energy 405 00:29:18,990 --> 00:29:20,218 electricity. 406 00:29:22,694 --> 00:29:26,460 And with it we are changing our whole perspective on time. 407 00:29:34,939 --> 00:29:36,804 Since we discovered electricity, 408 00:29:36,975 --> 00:29:39,671 time itself has been given the shock treatment. 409 00:29:44,816 --> 00:29:48,582 Life today would be impossible without electricity. 410 00:29:48,787 --> 00:29:51,813 Everything happens with the flick of a switch. 411 00:30:00,598 --> 00:30:03,499 Electricity has pushed everything into over-drive. 412 00:30:03,768 --> 00:30:05,235 It's the power behind the world's 413 00:30:05,403 --> 00:30:06,927 fastest growing city 414 00:30:07,205 --> 00:30:08,229 Las Vegas. 415 00:30:20,785 --> 00:30:21,376 One minute 416 00:30:21,553 --> 00:30:23,145 there's an empty plot of land, 417 00:30:23,521 --> 00:30:25,045 then a timber frame, 418 00:30:25,223 --> 00:30:27,487 turn the corner and the walls go up. 419 00:30:28,293 --> 00:30:30,352 Next street, the tiles go on. 420 00:30:31,396 --> 00:30:33,523 Opposite the houses are finished. 421 00:30:34,265 --> 00:30:37,257 And round the corner people have already moved in 422 00:30:37,435 --> 00:30:38,959 ready to live the dream. 423 00:30:45,810 --> 00:30:48,210 There can be a thousand new people a week, 424 00:30:48,379 --> 00:30:50,677 riding in on this power surge. 425 00:30:50,915 --> 00:30:52,883 It's taken just decades to turn 426 00:30:53,051 --> 00:30:56,452 a vast area of desert into downtown. 427 00:30:58,456 --> 00:31:00,515 But it's not just Vegas. 428 00:31:03,194 --> 00:31:04,525 It's everywhere. 429 00:31:04,963 --> 00:31:08,330 Electricity hasn't just transformed the world. 430 00:31:08,499 --> 00:31:10,831 It's turned night into day. 431 00:31:19,777 --> 00:31:21,642 In Vegas buildings go up, 432 00:31:21,813 --> 00:31:23,303 even in the dark. 433 00:31:30,655 --> 00:31:33,886 When the sun goes down, the city lights up. 434 00:31:38,129 --> 00:31:40,359 The effect is like a whoop of victory 435 00:31:40,531 --> 00:31:43,557 over our age-old slavery to daylight. 436 00:31:55,747 --> 00:31:58,910 Now there's no need to wait for anything. 437 00:32:05,857 --> 00:32:08,121 The slot machines, one-arm bandits, 438 00:32:08,293 --> 00:32:12,093 restaurants, are all open 24 hours a day. 439 00:32:15,566 --> 00:32:17,431 Dinnertime is anytime. 440 00:32:17,769 --> 00:32:20,203 Here you won't run out of time 441 00:32:20,405 --> 00:32:21,463 only money. 442 00:32:24,242 --> 00:32:26,210 This round-the-clock existence 443 00:32:26,377 --> 00:32:28,709 is not just changing our habits. 444 00:32:31,683 --> 00:32:34,151 Many of the animals that share our cities 445 00:32:34,319 --> 00:32:36,048 have always been nocturnal. 446 00:32:36,220 --> 00:32:38,586 But 24-hour light is making 447 00:32:38,756 --> 00:32:41,452 some of them behave in strange ways. 448 00:32:45,797 --> 00:32:47,128 Birds come into our cities 449 00:32:47,298 --> 00:32:49,198 for warmth from the lights, 450 00:32:49,367 --> 00:32:50,698 especially at Christmas. 451 00:32:53,037 --> 00:32:54,265 But the light has also meant 452 00:32:54,439 --> 00:32:57,465 that some birds are singing their dawn chorus 453 00:32:57,642 --> 00:32:58,904 in the middle of the night. 454 00:33:04,649 --> 00:33:06,617 The trees are confused too. 455 00:33:07,185 --> 00:33:10,518 Longer nights in autumn signal the shedding of leaves. 456 00:33:10,722 --> 00:33:12,849 But trees growing by street lamps 457 00:33:13,024 --> 00:33:16,516 are now keeping their leaves longer than those in the dark. 458 00:33:23,334 --> 00:33:27,430 We can only wonder what this is doing to our own body clocks. 459 00:33:27,605 --> 00:33:29,038 Electricity has encouraged us 460 00:33:29,207 --> 00:33:31,732 to expect more and more from our day. 461 00:33:31,976 --> 00:33:34,501 We're burning the candle at both ends. 462 00:33:40,818 --> 00:33:44,811 Electricity hasn't just accelerated changes to the landscape. 463 00:33:45,189 --> 00:33:48,852 It's given us control over the night as well as the day. 464 00:33:49,927 --> 00:33:52,987 It's changed our whole attitude to time. 465 00:33:56,734 --> 00:33:58,599 Today our need for speed means 466 00:33:58,770 --> 00:34:00,260 we want everything now. 467 00:34:01,339 --> 00:34:04,433 And with so many of us all chasing the clock, 468 00:34:04,609 --> 00:34:05,598 we must get our food 469 00:34:05,777 --> 00:34:08,746 from plant to plate as quickly as possible. 470 00:34:11,749 --> 00:34:12,943 How have we done that? 471 00:34:24,395 --> 00:34:26,625 Take rice - Across Asia 472 00:34:26,798 --> 00:34:30,495 it's the staple diet for two billion people. 473 00:34:35,273 --> 00:34:38,071 It feeds over half the world's population. 474 00:34:42,113 --> 00:34:43,045 In Indonesia 475 00:34:43,214 --> 00:34:45,808 the landscape is dominated by it. 476 00:34:46,150 --> 00:34:51,520 Huge tracts of the jungle have been replaced by rice fields and terraces. 477 00:34:58,896 --> 00:35:00,693 Devoting large areas of land 478 00:35:00,865 --> 00:35:03,356 to one single crop is the only way 479 00:35:03,534 --> 00:35:04,865 to feed so many people, 480 00:35:05,036 --> 00:35:06,526 quickly and easily. 481 00:35:16,114 --> 00:35:19,277 But this is just the start of high-speed farming. 482 00:35:19,617 --> 00:35:22,415 Rice growing still needs a large work force. 483 00:35:32,663 --> 00:35:35,393 And despite many hands making light work - 484 00:35:35,566 --> 00:35:38,797 it still takes a lot of time to grow and harvest. 485 00:35:46,911 --> 00:35:48,845 So what can be done to speed things up 486 00:35:49,013 --> 00:35:50,503 and save time? 487 00:35:53,351 --> 00:35:55,842 Where possible machines take over. 488 00:36:00,491 --> 00:36:02,652 This is how we get our daily bread. 489 00:36:02,827 --> 00:36:06,422 Huge combine harvesters clear wheat-fields quickly 490 00:36:06,597 --> 00:36:07,825 and efficiently. 491 00:36:17,808 --> 00:36:20,436 But there's another, bigger problem. 492 00:36:20,678 --> 00:36:25,479 Nature controls the speed at which food plants grow and ripen. 493 00:36:25,650 --> 00:36:26,947 And of course that dictates 494 00:36:27,118 --> 00:36:28,710 when they hit the shops. 495 00:36:29,887 --> 00:36:33,516 About 30 years ago tomatoes were only available in the summer. 496 00:36:34,258 --> 00:36:34,815 Now they're in our 497 00:36:34,992 --> 00:36:36,857 shopping trollies year-round. 498 00:36:37,028 --> 00:36:40,691 There are plum tomatoes, vine-ripened tomatoes, 499 00:36:40,865 --> 00:36:44,232 cherry tomatoes, vittoria, pomodorino. 500 00:36:44,468 --> 00:36:46,698 We have an insatiable appetite for them: 501 00:36:46,871 --> 00:36:51,399 The British alone consume 420,000 tonnes every year. 502 00:36:51,576 --> 00:36:52,235 What happened 503 00:36:52,410 --> 00:36:54,105 to the humble tomato? 504 00:36:55,012 --> 00:36:58,539 The tomato plant fell under our complete control. 505 00:36:58,849 --> 00:37:02,114 And what helped us do this was the glasshouse. 506 00:37:17,235 --> 00:37:18,429 With glasshouses, 507 00:37:18,603 --> 00:37:21,037 tomato growth went high-tech. 508 00:37:28,846 --> 00:37:30,040 In a short space of time 509 00:37:30,214 --> 00:37:33,706 the greenhouse has gone from rustic garden potting place 510 00:37:33,884 --> 00:37:36,352 to megalithic tomato factory. 511 00:37:39,323 --> 00:37:41,689 This one covers over 11 hectares 512 00:37:41,859 --> 00:37:43,326 of the English countryside. 513 00:37:45,096 --> 00:37:48,224 But it's about as far from nature as you can get. 514 00:37:48,399 --> 00:37:50,867 Is this is a window on the future? 515 00:37:57,108 --> 00:38:00,669 It's a precision-controlled world within a world, 516 00:38:00,845 --> 00:38:02,972 where growing time is compressed 517 00:38:03,147 --> 00:38:05,707 and tomatoes hurtle through their cycle 518 00:38:05,883 --> 00:38:07,578 at unnatural speed. 519 00:38:08,419 --> 00:38:10,717 They're grown in a special mineral base 520 00:38:10,888 --> 00:38:12,082 and drip-fed the water 521 00:38:12,256 --> 00:38:13,553 and food they need. 522 00:38:14,125 --> 00:38:18,687 As the temperature gets too hot the windows open automatically 523 00:38:18,863 --> 00:38:21,423 and once the best growing temperature is reached, 524 00:38:21,599 --> 00:38:22,566 they close. 525 00:38:24,535 --> 00:38:26,503 This is performance growth 526 00:38:26,804 --> 00:38:28,396 24 hours a day, 527 00:38:28,572 --> 00:38:29,834 7 days a week. 528 00:38:30,207 --> 00:38:32,641 Seasons are a thing of the past. 529 00:38:33,377 --> 00:38:34,605 There's even a boiler, 530 00:38:34,779 --> 00:38:38,078 which kicks in to stop the tomatoes catching a chill. 531 00:38:38,249 --> 00:38:40,149 Nothing is left to chance. 532 00:38:43,721 --> 00:38:45,484 They ripen double-quick 533 00:38:45,656 --> 00:38:47,055 and then they're picked. 534 00:38:52,763 --> 00:38:54,492 Even this happens round the clock. 535 00:38:54,665 --> 00:38:56,189 And although it's done by hand, 536 00:38:56,367 --> 00:38:58,460 it's made as easy as possible 537 00:38:58,636 --> 00:39:00,433 so no time is wasted. 538 00:39:09,046 --> 00:39:10,308 Demand is rocketing. 539 00:39:10,481 --> 00:39:12,005 It might not be long before we're eating 540 00:39:12,183 --> 00:39:14,879 more tomatoes than any other fruit. 541 00:39:15,753 --> 00:39:18,244 No wonder we're doing all we can to grow them 542 00:39:18,422 --> 00:39:19,719 as fast as possible. 543 00:39:27,798 --> 00:39:28,890 To speed up nature 544 00:39:29,066 --> 00:39:31,864 we have created artificial worlds. 545 00:39:32,403 --> 00:39:34,735 Is it only a matter of time before 546 00:39:34,905 --> 00:39:37,806 all we grow comes under our control? 547 00:39:43,614 --> 00:39:44,774 The tomato's rise, 548 00:39:44,949 --> 00:39:46,314 from market garden fruit 549 00:39:46,484 --> 00:39:47,849 to techno-plant, 550 00:39:48,018 --> 00:39:52,819 is just one of the many ways in which we've taken time and shrunk it. 551 00:39:53,157 --> 00:39:54,624 If you drive down time, 552 00:39:54,792 --> 00:39:56,282 you drive down cost. 553 00:39:56,460 --> 00:39:58,655 Time is now money. 554 00:40:05,803 --> 00:40:08,169 So, where on earth do we go from here? 555 00:40:42,540 --> 00:40:46,499 Iron-ore, coal, copper and aluminium 556 00:40:46,677 --> 00:40:50,135 are the raw ingredients of our material world. 557 00:40:50,848 --> 00:40:52,110 To get enough of them, 558 00:40:52,283 --> 00:40:54,774 you have to shift shed-Ioads of earth. 559 00:41:03,093 --> 00:41:06,119 This iron-ore mine in Australia 560 00:41:06,297 --> 00:41:08,162 is one of the most enormous holes 561 00:41:08,332 --> 00:41:10,698 in the ground we've ever created. 562 00:41:17,508 --> 00:41:19,339 But where are the miners? 563 00:41:19,510 --> 00:41:20,704 Who's doing all the work? 564 00:41:23,547 --> 00:41:26,516 Men have been replaced by monster machines. 565 00:41:34,058 --> 00:41:36,083 One 40 tonne scoop does the work 566 00:41:36,260 --> 00:41:38,922 of hundreds of men in a fraction of the time. 567 00:41:44,134 --> 00:41:46,625 The ultimate labour-saving device. 568 00:41:54,812 --> 00:41:58,509 Backbreaking work that used to take one man one month, 569 00:41:58,682 --> 00:42:00,741 now takes one minute. 570 00:42:07,458 --> 00:42:09,949 We have the power to move mountains. 571 00:42:22,673 --> 00:42:26,006 And what's more, we can do it with breath-taking speed. 572 00:42:29,313 --> 00:42:32,680 A mine that today takes 30 years to dig, might, 573 00:42:32,850 --> 00:42:35,512 in the future, take only 30 days. 574 00:42:43,994 --> 00:42:46,690 But what's behind the rush? 575 00:42:54,538 --> 00:42:57,166 This iron ore is the essential ingredient 576 00:42:57,341 --> 00:42:59,138 in our drive to beat time. 577 00:42:59,543 --> 00:43:00,874 It goes to make steel 578 00:43:01,045 --> 00:43:03,377 and beyond that, all the tools 579 00:43:03,547 --> 00:43:05,447 that save us precious minutes. 580 00:43:18,729 --> 00:43:20,856 But one product above all, 581 00:43:21,031 --> 00:43:23,499 has changed our experience of time. 582 00:43:24,401 --> 00:43:26,369 This train is carrying enough ore 583 00:43:26,537 --> 00:43:28,903 to make 15,000 of them. 584 00:43:29,306 --> 00:43:30,671 The most revolutionary time 585 00:43:30,841 --> 00:43:33,503 saving machine ever invented. 586 00:43:47,458 --> 00:43:49,949 The car, perhaps more than anything else, 587 00:43:50,127 --> 00:43:52,527 has accelerated the way we live. 588 00:43:54,832 --> 00:43:57,357 It's possibly our first ever time machine. 589 00:43:57,801 --> 00:43:58,927 It gives us the freedom 590 00:43:59,103 --> 00:44:00,434 to travel further, 591 00:44:00,604 --> 00:44:02,765 faster than ever before. 592 00:44:07,678 --> 00:44:10,841 The first ones didn't exactly take your breath away. 593 00:44:13,450 --> 00:44:14,940 Though at the time people thought 594 00:44:15,119 --> 00:44:17,986 you'd suffocate if you went much faster. 595 00:44:22,159 --> 00:44:23,888 But that didn't hold us back! 596 00:44:24,161 --> 00:44:25,128 Top speeds have gone 597 00:44:25,295 --> 00:44:27,354 from barely more than walking pace to 598 00:44:27,531 --> 00:44:31,991 over 300 kilometres per hour, in less than a century. 599 00:44:50,587 --> 00:44:51,519 A century ago 600 00:44:51,689 --> 00:44:54,021 most people never left their own village. 601 00:44:54,258 --> 00:44:55,486 Today we can get to anywhere 602 00:44:55,659 --> 00:44:58,560 on the planet in less than 48 hours. 603 00:45:12,276 --> 00:45:16,406 Because we can get about so fast, we're always on the move. 604 00:45:32,830 --> 00:45:35,628 Speed is how we beat time. 605 00:45:36,934 --> 00:45:40,165 And speed may be the key to our ultimate dream. 606 00:45:40,704 --> 00:45:41,864 Time travel. 607 00:45:45,976 --> 00:45:48,843 Imagine being able to turn back the clock, 608 00:45:49,012 --> 00:45:50,536 and relive your life. 609 00:45:53,283 --> 00:45:56,741 Imagine turning your car into a time machine 610 00:45:56,920 --> 00:45:58,911 and taking a journey through time. 611 00:46:03,127 --> 00:46:05,322 Well today we are much closer 612 00:46:05,496 --> 00:46:08,431 to turning this dream into a reality. 613 00:46:09,933 --> 00:46:11,298 And that's because we now know 614 00:46:11,468 --> 00:46:14,995 there's no such thing as the constant march of time. 615 00:46:20,878 --> 00:46:23,369 In 1905 Albert Einstein 616 00:46:23,547 --> 00:46:25,572 suggested the mind-bending theory 617 00:46:25,749 --> 00:46:28,274 that time varies with speed. 618 00:46:28,685 --> 00:46:30,778 He proved that the length of one second 619 00:46:30,954 --> 00:46:32,945 depends on how fast you're moving. 620 00:46:33,423 --> 00:46:36,915 The faster you travel the slower that second would take. 621 00:46:40,898 --> 00:46:43,128 So what would this mean in practice? 622 00:46:47,838 --> 00:46:49,271 Take these twins. 623 00:46:49,439 --> 00:46:52,875 One travels into space at phenomenal speed, 624 00:46:53,043 --> 00:46:55,511 leaving his brother behind on earth. 625 00:46:58,916 --> 00:47:01,407 Neither will notice a change in time 626 00:47:01,585 --> 00:47:02,745 but when they meet again 627 00:47:02,920 --> 00:47:04,581 they'll see a big difference. 628 00:47:05,923 --> 00:47:08,983 When our space traveller completes what was - for him 629 00:47:09,159 --> 00:47:10,353 a 4-month trip, 630 00:47:10,828 --> 00:47:15,288 he finds his brother on earth has aged over 40 years. 631 00:47:16,934 --> 00:47:18,128 The younger twin has time 632 00:47:18,302 --> 00:47:20,793 travelled into his brother's future. 633 00:47:27,477 --> 00:47:29,638 So how fast would he have been going? 634 00:47:29,980 --> 00:47:32,505 Something close to the speed of light. 635 00:47:32,883 --> 00:47:37,149 That's around 300,000 kilometres per second. 636 00:47:39,957 --> 00:47:42,289 But is this actually possible? 637 00:47:43,460 --> 00:47:45,189 Well in just 100 years we've gone 638 00:47:45,362 --> 00:47:50,322 from top speeds of 12 kilometres an hour to 7 times the speed of sound. 639 00:47:50,701 --> 00:47:53,465 The speed of light is still a long way off, 640 00:47:53,804 --> 00:47:57,205 but new breakthroughs could find us hurtling towards 641 00:47:57,374 --> 00:47:58,966 it faster than we ever imagined. 642 00:48:00,544 --> 00:48:03,741 However far-fetched time travel may seem, 643 00:48:03,914 --> 00:48:05,973 don't brush it off as a dream. 644 00:48:06,183 --> 00:48:09,311 Lots of things once seemed impossible. 645 00:48:12,890 --> 00:48:14,255 A little over a hundred years ago, 646 00:48:14,424 --> 00:48:18,485 the idea of talking to someone on the other side of the world, 647 00:48:18,662 --> 00:48:19,890 would have been laughed at. 648 00:48:21,899 --> 00:48:24,459 Today a telephone call to New Zealand 649 00:48:24,635 --> 00:48:26,933 where words move at the speed of light 650 00:48:27,104 --> 00:48:28,401 is taken for granted. 651 00:48:28,805 --> 00:48:30,295 So time travel might happen 652 00:48:30,474 --> 00:48:31,771 sooner than you think. 653 00:48:35,078 --> 00:48:38,138 But what about the time travel we see in science fiction? 654 00:48:38,548 --> 00:48:41,540 Going back, as well as forward, in time? 655 00:48:45,188 --> 00:48:49,887 Scientists have discovered tunnels that connect two areas of space, 656 00:48:50,060 --> 00:48:51,960 which might just do this. 657 00:48:52,429 --> 00:48:54,761 These tunnels, called wormholes, 658 00:48:54,932 --> 00:48:57,492 are a short cut between two points in time. 659 00:48:59,236 --> 00:49:01,830 At the moment it's still a theory 660 00:49:02,105 --> 00:49:03,834 but, given time... 661 00:49:05,575 --> 00:49:08,976 So, if you could become a Time Lord, 662 00:49:09,146 --> 00:49:11,011 what power would you have? 663 00:49:11,381 --> 00:49:13,246 Just imagine the options. 664 00:49:14,584 --> 00:49:17,644 You could head into the future to visit your great grandchildren, 665 00:49:17,821 --> 00:49:20,381 perhaps even see their children's children. 666 00:49:23,026 --> 00:49:25,187 What kind of world would they be living in? 667 00:49:28,598 --> 00:49:31,158 You might prefer to take a trip into the past. 668 00:49:36,039 --> 00:49:38,269 Visit the world of the ancient Egyptians 669 00:49:38,442 --> 00:49:40,774 and see how they built the pyramids. 670 00:49:45,916 --> 00:49:49,215 Would you tell the early fire-makers of Australia 671 00:49:49,386 --> 00:49:51,115 the consequences of their actions? 672 00:49:56,526 --> 00:49:59,290 Maybe you'd go see the spectacles of the world, 673 00:49:59,463 --> 00:50:02,159 witness the creation of the Grand Canyon. 674 00:50:06,169 --> 00:50:08,865 You could even walk with dinosaurs... 675 00:50:13,710 --> 00:50:15,769 Would you go back into the unknown, 676 00:50:15,946 --> 00:50:18,380 over 15 billion years, 677 00:50:18,548 --> 00:50:24,180 to witness the creation of the Universe and the very beginning of Time? 678 00:50:27,824 --> 00:50:31,316 If you could become a true master of time 679 00:50:31,561 --> 00:50:32,789 where would you go? 680 00:50:33,163 --> 00:50:35,893 What would you dare to change?