1 00:00:01,635 --> 00:00:03,291 Lying just beneath everyday reality 2 00:00:03,420 --> 00:00:06,207 is a breathtaking world, 3 00:00:06,298 --> 00:00:10,291 where much of what we perceive about the universe is wrong. 4 00:00:10,427 --> 00:00:13,919 Physicist and best-selling author Brain Greene takes you 5 00:00:14,056 --> 00:00:17,594 on a journey that bends the rules of human experience. 6 00:00:17,684 --> 00:00:20,596 Why don't we ever see events unfold in reverse order? 7 00:00:20,729 --> 00:00:24,392 According to the laws of physics, this can happen. 8 00:00:26,151 --> 00:00:28,483 It's a world that comes to light 9 00:00:28,612 --> 00:00:32,025 as we probe the most extreme realms of the cosmos, 10 00:00:32,115 --> 00:00:35,073 from black holes to the Big Bang 11 00:00:35,160 --> 00:00:37,025 to the very heart of matter itself. 12 00:00:37,120 --> 00:00:38,906 I'm going to have what he's having. 13 00:00:38,997 --> 00:00:43,411 Here, our universe may be one of numerous parallel realities. 14 00:00:43,502 --> 00:00:47,370 The three-dimensional world may be just an illusion. 15 00:00:47,464 --> 00:00:48,544 and there is no distinction 16 00:00:48,632 --> 00:00:51,715 between past, present and future. 17 00:00:53,845 --> 00:00:56,006 But how could this be? 18 00:00:56,139 --> 00:00:59,848 How could we be so wrong about something so familiar? 19 00:00:59,977 --> 00:01:00,807 Does it bother us? 20 00:01:00,936 --> 00:01:01,891 Absolutely. 21 00:01:01,979 --> 00:01:05,312 There's no principle built into the laws of nature 22 00:01:05,440 --> 00:01:09,308 that say that theoretical physicists have to be happy. 23 00:01:09,403 --> 00:01:11,940 It's a game-changing perspective 24 00:01:12,030 --> 00:01:15,739 that opens up a whole new world of possibiblities. 25 00:01:15,826 --> 00:01:16,815 Coming up... 26 00:01:16,910 --> 00:01:20,494 What if you took all this stuff away? 27 00:01:20,622 --> 00:01:23,034 We're left with empty space. 28 00:01:23,166 --> 00:01:24,952 But what seems like nothing 29 00:01:25,043 --> 00:01:28,126 is actually teeming with ferocious activity. 30 00:01:28,213 --> 00:01:29,999 What is space? 31 00:01:30,132 --> 00:01:32,589 It is one of the deepest mysteries in physics. 32 00:01:32,676 --> 00:01:35,338 Could its elusive ingredients hold the key 33 00:01:35,470 --> 00:01:37,381 to the fate of the universe? 34 00:01:37,514 --> 00:01:40,927 "The Fabric of the Cosmos," right now on NOVA. 35 00:01:56,116 --> 00:01:59,199 Major funding for NOVA is provided by the following: 36 00:02:05,709 --> 00:02:07,324 And... 37 00:02:18,055 --> 00:02:22,173 And by the Corporation for Public Broadcasting 38 00:02:22,267 --> 00:02:25,225 and by contributions to your PBs station from: 39 00:02:32,402 --> 00:02:35,018 Major funding for "The Fabric of the Cosmos" 40 00:02:35,113 --> 00:02:37,900 is provided by the National Science Foundation. 41 00:02:45,582 --> 00:02:47,698 And... 42 00:02:50,462 --> 00:02:53,124 Supporting original research and public understanding 43 00:02:53,256 --> 00:02:59,343 of science, technology, engineering and mathematics. 44 00:02:59,429 --> 00:03:01,420 Additional funding is provided by... 45 00:03:12,943 --> 00:03:15,184 And the George D.Smith Fund. 46 00:03:39,803 --> 00:03:44,137 We think of our world as filled with stuff, 47 00:03:44,224 --> 00:03:47,512 like buildings and cars... 48 00:03:47,644 --> 00:03:50,101 buses and people. 49 00:03:50,188 --> 00:03:53,430 And nowhere does that seem more apparent than in a crowded city 50 00:03:53,525 --> 00:03:54,685 like New York. 51 00:03:57,028 --> 00:03:59,861 Yet all around the stuff that makes up our everyday world... 52 00:04:01,616 --> 00:04:07,156 is something as important but far more mysterious, 53 00:04:07,247 --> 00:04:12,867 the space in which all this stuff exists. 54 00:04:13,003 --> 00:04:15,164 To get a feel for what I'm talking about, 55 00:04:15,255 --> 00:04:17,667 let's stop for a moment and imagine. 56 00:04:21,511 --> 00:04:24,469 What if you took all this stuff away? 57 00:04:26,308 --> 00:04:27,844 I mean all of it: 58 00:04:27,934 --> 00:04:32,018 the people... 59 00:04:32,147 --> 00:04:35,184 the cars and buildings. 60 00:04:35,317 --> 00:04:39,151 And not just the stuff here on earth, 61 00:04:39,237 --> 00:04:40,852 but the earth itself. 62 00:04:43,033 --> 00:04:48,027 What if you took away all the planets,stars and galaxies? 63 00:04:48,121 --> 00:04:51,488 And not just the big stuff, 64 00:04:51,583 --> 00:04:57,670 but tiny things down to the very last atoms of gas and dust. 65 00:04:57,756 --> 00:05:01,544 What if you took it all away? 66 00:05:01,635 --> 00:05:03,626 What would be left? 67 00:05:03,720 --> 00:05:06,507 Most of us woud say "nothing". 68 00:05:06,598 --> 00:05:08,805 And we'd be right. 69 00:05:08,892 --> 00:05:12,350 But strangely, we'd also be wrong. 70 00:05:12,437 --> 00:05:14,769 What's left is empty space. 71 00:05:14,898 --> 00:05:19,062 And as it turns out, empty space is not nothing. 72 00:05:19,152 --> 00:05:20,688 It's something. 73 00:05:20,779 --> 00:05:23,896 Something with hidden characteristics as real 74 00:05:24,032 --> 00:05:26,273 as all the stuff in our everyday lives. 75 00:05:26,409 --> 00:05:32,530 In fact, space is so real it can bend... 76 00:05:32,624 --> 00:05:34,330 Space can twist... 77 00:05:37,420 --> 00:05:38,751 And it can ripple. 78 00:05:40,715 --> 00:05:44,003 So real that empty space itself helps shape 79 00:05:44,094 --> 00:05:46,506 everything in the world around us 80 00:05:46,596 --> 00:05:50,009 and forms the very fabric of the cosmos. 81 00:05:52,310 --> 00:05:54,096 You can't understand anything about the world 82 00:05:54,229 --> 00:05:55,264 unless you understand space 83 00:05:55,397 --> 00:05:57,729 because that's the world the world is space. 84 00:05:57,816 --> 00:05:58,896 With stuff in it 85 00:05:58,984 --> 00:06:01,270 We're not usually very conscious of space. 86 00:06:01,361 --> 00:06:02,897 But then again, I tell people, 87 00:06:02,988 --> 00:06:04,603 fish are probably not conscious of water either. 88 00:06:04,739 --> 00:06:05,945 They're in it all the time. 89 00:06:06,032 --> 00:06:07,772 Space is not really nothing. 90 00:06:07,868 --> 00:06:10,109 It actually has a lot going on inside. 91 00:06:13,665 --> 00:06:16,327 When most of us picture space, 92 00:06:16,459 --> 00:06:21,123 we think of outer space-a place that's far,far away. 93 00:06:21,256 --> 00:06:24,498 But space is actually everywhere. 94 00:06:24,634 --> 00:06:25,840 You could say 95 00:06:25,969 --> 00:06:28,176 it's the most abundant thing in the universe 96 00:06:28,305 --> 00:06:31,138 Even the tiniest of things like atoms, 97 00:06:31,224 --> 00:06:35,593 the basic ingredient in you and me and everything else we see 98 00:06:35,687 --> 00:06:36,972 in the world around us, 99 00:06:37,063 --> 00:06:40,772 even they are almost entirely empty space. 100 00:06:43,069 --> 00:06:45,151 In fact, if you removed all the space 101 00:06:45,238 --> 00:06:50,198 inside all the atoms making up the stone, glass and steel 102 00:06:50,327 --> 00:06:52,784 of the Empire State Building, 103 00:06:52,871 --> 00:06:54,987 you'd be left with a little lump... 104 00:06:57,918 --> 00:07:00,330 about the size of a grain of rice, 105 00:07:00,337 --> 00:07:03,579 but weighing hunbreds of millions of pounds 106 00:07:03,673 --> 00:07:07,666 The rest is only empty space. 107 00:07:07,761 --> 00:07:11,128 But what exactly is space? 108 00:07:11,222 --> 00:07:15,215 I can show you a picture of Spain... 109 00:07:15,352 --> 00:07:17,092 of Napoleon... 110 00:07:17,187 --> 00:07:19,178 of my Uncle Harold. 111 00:07:19,272 --> 00:07:22,264 But space looks like this. 112 00:07:22,359 --> 00:07:24,065 Nothing. 113 00:07:24,194 --> 00:07:27,027 So how do you make sense of something 114 00:07:27,155 --> 00:07:28,736 that looks like nothing? 115 00:07:28,865 --> 00:07:30,526 Why is there space 116 00:07:30,659 --> 00:07:32,445 rather than no space? 117 00:07:32,535 --> 00:07:34,526 Why is space three-dimensional? 118 00:07:34,621 --> 00:07:36,782 Why is space big? 119 00:07:36,873 --> 00:07:38,864 We have a lot of room to move around in. 120 00:07:38,959 --> 00:07:40,699 How come it's not tiny? 121 00:07:40,835 --> 00:07:42,746 Um... 122 00:07:42,879 --> 00:07:44,744 We have no consensus about these things. 123 00:07:44,881 --> 00:07:46,087 What is space? 124 00:07:46,216 --> 00:07:48,207 We actually still don't really know. 125 00:07:48,301 --> 00:07:52,635 It is one of the deepest mysteries in physics. 126 00:07:54,224 --> 00:07:57,261 Fortunately,we're not completely in the dark. 127 00:07:57,394 --> 00:08:01,228 Wa're been gathering clues about space for centturies. 128 00:08:01,314 --> 00:08:03,054 Some of the earlist came 129 00:08:03,149 --> 00:08:07,062 from thinking about how objects move through space. 130 00:08:07,195 --> 00:08:10,938 To get a feel for this, take a look at that skater. 131 00:08:11,074 --> 00:08:13,565 As she glides across the rink, 132 00:08:13,702 --> 00:08:16,990 she's moving in relation to everything around her, 133 00:08:17,080 --> 00:08:18,616 like the ice. 134 00:08:18,748 --> 00:08:21,114 And when she goes into a spin, 135 00:08:21,251 --> 00:08:24,163 not any can she see that she's spinning, 136 00:08:24,254 --> 00:08:26,870 she can also feel it, 137 00:08:26,965 --> 00:08:30,708 because as she spins, she feels her arms pulled outward. 138 00:08:32,637 --> 00:08:34,047 But now let's imagine 139 00:08:34,139 --> 00:08:37,222 that you could take away at the stuff around her, 140 00:08:37,308 --> 00:08:41,802 from the rink... 141 00:08:41,938 --> 00:08:45,931 to the most distant galaxies. 142 00:08:46,026 --> 00:08:48,608 So the only thing left is the skater 143 00:08:48,695 --> 00:08:52,734 spinning in completely empty space. 144 00:08:52,824 --> 00:08:55,907 If the skater still feels her arms pulled outward, 145 00:08:55,994 --> 00:08:58,280 she'll know she's spinning. 146 00:08:58,371 --> 00:09:01,113 But if empty space is nothing, 147 00:09:01,249 --> 00:09:04,457 what is she spinning in relation to? 148 00:09:04,586 --> 00:09:06,952 Imagine you're that skater. 149 00:09:07,088 --> 00:09:09,124 When you look out, you don't see anything. 150 00:09:09,257 --> 00:09:13,250 It's just uniform, still blackness all around you. 151 00:09:13,344 --> 00:09:16,256 And yet, your arms are beings pulled outwards. 152 00:09:16,347 --> 00:09:17,632 So you say to yourself, 153 00:09:17,766 --> 00:09:20,348 what could I be spinning with respect to? 154 00:09:20,477 --> 00:09:23,219 Is there something out there that I'm not seeing? 155 00:09:25,732 --> 00:09:28,849 Trying to answer questions like these, 156 00:09:28,985 --> 00:09:32,443 scientists came up with a bold new picture of space. 157 00:09:32,530 --> 00:09:36,273 And the key was to make something out of nothing. 158 00:09:42,832 --> 00:09:45,164 When you go to the theater, you watch the actors... 159 00:09:45,251 --> 00:09:48,618 I do confess that I love nothing in the world so well as thee. 160 00:09:48,713 --> 00:09:50,954 ...the scenery,the story. 161 00:09:51,049 --> 00:09:52,585 I protest I love thee... 162 00:09:52,675 --> 00:09:55,838 Well, then God forgive me! 163 00:09:55,929 --> 00:09:57,885 What offence, sweet Beatrice? 164 00:09:58,014 --> 00:09:59,299 But there's something important here 165 00:09:59,390 --> 00:10:02,006 that you won't find mentioned in the playbill 166 00:10:04,229 --> 00:10:07,016 Something we hardly ever notice. 167 00:10:14,906 --> 00:10:16,066 The stage. 168 00:10:16,199 --> 00:10:19,737 It's an absolutely vital part of the show, 169 00:10:19,869 --> 00:10:25,034 and yet most of us, we don't even give it a second thought. 170 00:10:25,125 --> 00:10:29,835 But Isaac Newton, he did. 171 00:10:29,921 --> 00:10:34,210 This is how the father of modern science pictured space: 172 00:10:34,300 --> 00:10:35,756 as an empty stage. 173 00:10:35,885 --> 00:10:39,093 To Newton, space was the framework 174 00:10:39,222 --> 00:10:42,055 for everything that happens in the cosmos, 175 00:10:42,183 --> 00:10:46,722 the arena within which the drama of the universe plays out. 176 00:10:46,855 --> 00:10:50,143 And Newton's stage was passive-- 177 00:10:50,233 --> 00:10:53,350 absolute,eternal and unchanging. 178 00:10:53,444 --> 00:10:55,526 The action couldn't affect the stage 179 00:10:55,613 --> 00:10:58,730 and the stage couldn't affect the action. 180 00:11:01,119 --> 00:11:03,531 By picturing space in this way, 181 00:11:03,621 --> 00:11:05,657 Newton was able to describe the world. 182 00:11:05,748 --> 00:11:09,036 as no one had ever done before. 183 00:11:09,127 --> 00:11:12,039 His unchanging stage allowed him to understand 184 00:11:12,130 --> 00:11:14,542 almost all motion we can see around us, 185 00:11:14,632 --> 00:11:17,339 yielding laws that can predict everything 186 00:11:17,427 --> 00:11:21,261 from the way apples fall from trees... 187 00:11:21,347 --> 00:11:24,931 to the path the earth takes around the sun. 188 00:11:25,059 --> 00:11:28,267 These laws worked so well that we still use them 189 00:11:28,396 --> 00:11:30,387 for the things we do today, 190 00:11:30,481 --> 00:11:35,020 from launching satellites... 191 00:11:35,111 --> 00:11:38,069 to landing airplanes. 192 00:11:38,156 --> 00:11:45,619 And the laws all hinge on one radical idea:space is real. 193 00:11:45,747 --> 00:11:49,535 Even though you can't see it or smell it or touch it, 194 00:11:49,626 --> 00:11:52,459 space is enough of a real, physical thing 195 00:11:52,545 --> 00:11:56,379 to provide a benchmark for certain kinds of motion, 196 00:11:56,466 --> 00:11:58,457 like that skater. 197 00:11:58,593 --> 00:12:01,926 Newton would say that when she spins, her arms splay out 198 00:12:02,013 --> 00:12:05,551 because she is spinning with respect to something 199 00:12:05,642 --> 00:12:09,055 and that something is space itself. 200 00:12:11,940 --> 00:12:14,226 GATES: Philosophers had been debating the nature of space 201 00:12:14,317 --> 00:12:16,273 for a very long time. 202 00:12:16,361 --> 00:12:19,148 What Newton does is change the terms of the debate, 203 00:12:19,280 --> 00:12:20,360 and with that, 204 00:12:20,490 --> 00:12:22,822 essentially, modern science gets born. 205 00:12:24,661 --> 00:12:27,118 Newton's stage was a huge hit. 206 00:12:27,205 --> 00:12:30,993 It enjoyed the limelight for over 200 years. 207 00:12:31,125 --> 00:12:34,083 But in the early decades of the 20th century, 208 00:12:34,170 --> 00:12:36,957 a new set of ideas emerged 209 00:12:37,048 --> 00:12:39,209 that shook Newton's stage to its very foundations. 210 00:12:40,718 --> 00:12:41,958 Ideas put forward 211 00:12:42,053 --> 00:12:45,921 by a young clerk working in a Swiss patent office. 212 00:12:46,015 --> 00:12:47,846 His name? 213 00:12:47,934 --> 00:12:48,844 Albert Einstein. 214 00:12:50,436 --> 00:12:53,052 Einstein grew up in the late 1800s, 215 00:12:53,189 --> 00:12:56,773 at the dawn of the age of electricity. 216 00:12:56,859 --> 00:12:59,191 Electric power was lighting up cities, 217 00:12:59,279 --> 00:13:02,362 giving rise to all kinds of technologies 218 00:13:02,490 --> 00:13:05,698 Newton could never have imagined. 219 00:13:05,785 --> 00:13:08,026 All of these developments tapped into something 220 00:13:08,121 --> 00:13:12,865 that had captivated Einstein since he was a child:light. 221 00:13:13,001 --> 00:13:15,617 Not light bulbs and street lamps,, 222 00:13:15,712 --> 00:13:18,374 but the very nature of light itself. 223 00:13:18,506 --> 00:13:19,996 and it was his fascination 224 00:13:20,091 --> 00:13:23,424 with one particularly weird feature of light--its speed-- 225 00:13:23,553 --> 00:13:25,418 that would lead Einstein to overturn 226 00:13:25,555 --> 00:13:26,886 Newton's picture of space. 227 00:13:29,017 --> 00:13:31,383 To see how,let's take a ride. 228 00:13:38,026 --> 00:13:42,190 Right now, we're traveling at about 20 miles per hour. 229 00:13:42,280 --> 00:13:45,238 To go faster,all the driver needs to do 230 00:13:45,366 --> 00:13:50,156 is step on the gas and the cab's speed changes. 231 00:13:50,246 --> 00:13:53,830 Now, you can feel that change, but you can also see it. 232 00:13:53,916 --> 00:13:59,661 on the cab's speedometer or on one of those radar speed signs. 233 00:13:59,756 --> 00:14:02,213 Okay,you can slow it down now. 234 00:14:03,593 --> 00:14:06,130 But now imagine that instead of measuring the speed of the cab, 235 00:14:06,262 --> 00:14:09,220 you have a radar sign that measures the speed 236 00:14:09,307 --> 00:14:12,265 of the light coming off its headlights. 237 00:14:12,393 --> 00:14:15,180 That sign would measure the light traveling 238 00:14:15,271 --> 00:14:21,016 at an astounding 671 million miles an hour. 239 00:14:21,110 --> 00:14:22,771 Now, when the cab starts moving, 240 00:14:22,904 --> 00:14:25,987 you'd think that the speed of the light would increase 241 00:14:26,115 --> 00:14:28,071 by the same amount as the car. 242 00:14:28,159 --> 00:14:32,448 After all, you'd think that the moving cab would give the light 243 00:14:32,538 --> 00:14:33,573 an extra push. 244 00:14:33,664 --> 00:14:39,375 But surprisingly, that's not what happens. 245 00:14:39,462 --> 00:14:43,171 Our radar sign--or any measurement of lights speed-- 246 00:14:43,299 --> 00:14:45,290 will always detect light traveling 247 00:14:45,426 --> 00:14:48,793 at 671 million miles per hour, 248 00:14:48,888 --> 00:14:51,425 whether the cab is moving or not. 249 00:14:51,516 --> 00:14:53,507 But how could this be? 250 00:14:53,643 --> 00:14:56,259 How could all measurements of light's speed 251 00:14:56,354 --> 00:14:58,310 always come out the same? 252 00:14:58,439 --> 00:15:01,647 If you're running at a wall, it's coming at you faster 253 00:15:01,776 --> 00:15:04,609 than if you're standing still with respect to that wall. 254 00:15:04,695 --> 00:15:06,105 But that's not true with light. 255 00:15:06,197 --> 00:15:10,486 The speed of light is the same for everybody 256 00:15:10,618 --> 00:15:12,984 That's really extraordinary. 257 00:15:13,121 --> 00:15:16,284 So here's how Einstein made sense 258 00:15:16,374 --> 00:15:18,535 of this extraordinary puzzle. 259 00:15:18,668 --> 00:15:22,456 Knowing that speed is just a measure of the space 260 00:15:22,547 --> 00:15:24,754 that something travels over time, 261 00:15:24,841 --> 00:15:28,333 Einstein proposed a truly stunning idea. 262 00:15:28,469 --> 00:15:32,007 that space and time could work together, 263 00:15:32,098 --> 00:15:35,682 constantly adjusting by exactly the right amount 264 00:15:35,768 --> 00:15:38,430 so that no matter how fast you might be moving 265 00:15:38,521 --> 00:15:39,977 when you measure the speed of light. 266 00:15:40,064 --> 00:15:44,683 it always comes out to be 671 million miles per hour. 267 00:15:47,363 --> 00:15:51,527 To respect that absolute quality about light, 268 00:15:51,617 --> 00:15:53,903 time had to cease to be absolute. 269 00:15:54,036 --> 00:15:55,526 Space had to cease to be absolute 270 00:15:55,621 --> 00:15:58,112 And these two had to become relative in such a way 271 00:15:58,207 --> 00:16:00,038 that they slosh between each other. 272 00:16:02,003 --> 00:16:04,710 If space and time being flexible sounds unfamiliar. 273 00:16:04,797 --> 00:16:07,914 it's only because we don't move fast enough in everyday life 274 00:16:08,050 --> 00:16:09,540 to see it in action. 275 00:16:09,635 --> 00:16:12,502 But if this cab could move near the speed of light, 276 00:16:12,597 --> 00:16:15,213 the effects would no longer be hidden. 277 00:16:18,186 --> 00:16:20,643 For example, if you were on a street corner 278 00:16:20,730 --> 00:16:22,721 as I went by close to the speed of light 279 00:16:22,815 --> 00:16:25,557 you'd see space adjusting, 280 00:16:25,651 --> 00:16:30,441 so that my cab, it would appear just inches long, 281 00:16:30,573 --> 00:16:35,283 and you'd also hear my watch ticking off time very slowly. 282 00:16:35,411 --> 00:16:38,073 But from my perspective inside the cab, 283 00:16:38,206 --> 00:16:40,913 my watch would be ticking normally 284 00:16:41,042 --> 00:16:44,159 and space in here would appear as it always does. 285 00:16:45,880 --> 00:16:50,590 But when I look outside the cab, I'd see space wildly adjusting. 286 00:16:50,676 --> 00:16:53,588 All to keep the speed of light constant. 287 00:16:55,515 --> 00:16:56,925 So with Einstein, 288 00:16:57,016 --> 00:17:01,430 time and space are no longer rigid and absolute. 289 00:17:01,562 --> 00:17:04,395 Instead, they meld together with motion, 290 00:17:04,482 --> 00:17:08,896 forming a single entity that came to be called "spacetime." 291 00:17:10,780 --> 00:17:13,146 I think as we live our life every day, 292 00:17:13,282 --> 00:17:16,319 we live with a Newtonian picture of space and time. 293 00:17:16,452 --> 00:17:17,908 It's something that we are confortable with. 294 00:17:17,995 --> 00:17:24,412 But Einstein was able to make reason conquer sense. 295 00:17:24,502 --> 00:17:27,369 That really was the genius of Einstein. 296 00:17:28,798 --> 00:17:32,461 this notion that space and time are a unity 297 00:17:32,552 --> 00:17:34,133 to me is one of the greatest insights 298 00:17:34,262 --> 00:17:35,468 that has ever occurred in science. 299 00:17:35,596 --> 00:17:37,302 It's so counterintuitive 300 00:17:37,431 --> 00:17:40,298 to everything we're ever experienced as human beings. 301 00:17:43,062 --> 00:17:44,893 And in the hands of Albert Einstein, 302 00:17:44,981 --> 00:17:48,348 this new picture of space would solve a deep mystery 303 00:17:48,484 --> 00:17:53,729 having to do with the most familiar force in the cosmos: 304 00:17:53,823 --> 00:17:56,155 Gravity 305 00:17:56,284 --> 00:17:59,822 Newton knew that gravity is a force that attracts objects 306 00:17:59,912 --> 00:18:01,197 to each ether. 307 00:18:01,330 --> 00:18:03,616 And his laws perdiceted the strength of this force 308 00:18:03,708 --> 00:18:06,324 with fantastic precision. 309 00:18:06,460 --> 00:18:10,419 But how does gravity actually work? 310 00:18:10,506 --> 00:18:12,838 How does the earth pull on the moon 311 00:18:12,925 --> 00:18:17,089 across hundreds of thousands of miles of empty space? 312 00:18:17,179 --> 00:18:19,545 They behave as if they are connected 313 00:18:19,682 --> 00:18:21,843 by some kind of invisible rope. 314 00:18:21,934 --> 00:18:25,677 But everyone knew that wasn't true. 315 00:18:25,771 --> 00:18:28,979 And Newton's laws provided no explanation. 316 00:18:29,066 --> 00:18:31,352 Einstein found 317 00:18:31,485 --> 00:18:34,522 that no band-aid patches would fix Newtonian gravity. 318 00:18:34,655 --> 00:18:36,900 He had to invent a mechanism for it, 319 00:18:36,901 --> 00:18:38,523 he had to understand it. 320 00:18:38,618 --> 00:18:43,453 After puzzling over this problem for more than ten years. 321 00:18:43,539 --> 00:18:46,997 Einstein reached a startling conclusion: 322 00:18:47,084 --> 00:18:51,202 the secret to gravity lay in the nature of spacetime. 323 00:18:51,339 --> 00:18:56,709 It was even more flexible than he had previously realized. 324 00:18:56,844 --> 00:19:00,803 It could stretch, like an actual fabric. 325 00:19:00,890 --> 00:19:05,384 This was a truly radical break from Newton. 326 00:19:05,519 --> 00:19:08,807 Think of this table as spacetime, 327 00:19:08,898 --> 00:19:12,106 and think of these balls as objects in space. 328 00:19:12,234 --> 00:19:15,601 Now, if specetime were nice and flat 329 00:19:15,738 --> 00:19:18,000 like the surface of this table. 330 00:19:18,532 --> 00:19:22,445 objects would travel in straight lines. 331 00:19:22,578 --> 00:19:26,070 But if space is like a fabric that can stretch and bend? 332 00:19:26,207 --> 00:19:28,698 Well, this may seem a little strange. 333 00:19:28,793 --> 00:19:34,038 But watch what happens if I put something heavy 334 00:19:34,131 --> 00:19:37,464 on the stretchy spacetime fabric. 335 00:19:42,181 --> 00:19:44,763 Now if I take my shot again... 336 00:19:48,229 --> 00:19:52,063 The ball travells along an indentation in the fabric 337 00:19:52,149 --> 00:19:53,434 that the heavier object creates. 338 00:19:53,526 --> 00:19:59,772 And this, Einstein realized, is how gravity actually works. 339 00:19:59,865 --> 00:20:04,655 It's the warping of spacetime caused by the objects within it. 340 00:20:04,787 --> 00:20:10,407 In other words, gravity is the shape of spacetime itself. 341 00:20:10,501 --> 00:20:14,961 The moon is kept in orbit not because it's pulled to the earth 342 00:20:15,047 --> 00:20:17,129 by some mysterious force, 343 00:20:17,216 --> 00:20:19,832 but rather because it rolls along a curve 344 00:20:19,969 --> 00:20:22,506 in the specetime fabric that the earth creates. 345 00:20:25,015 --> 00:20:31,636 With Einstein, space became not really real,but flexiable. 346 00:20:31,731 --> 00:20:32,811 So suddenly space had properties. 347 00:20:32,940 --> 00:20:34,896 Suddenly space had curvature. 348 00:20:34,984 --> 00:20:37,691 Suddenly space had a flexible kind of geometry 349 00:20:37,820 --> 00:20:40,812 almost like a rubber sheet. 350 00:20:42,575 --> 00:20:47,285 It opens up a whole new way of thinking about reality 351 00:20:47,371 --> 00:20:50,454 that describes the entire universe. 352 00:20:50,541 --> 00:20:54,659 Einstein becomes "Einstein" becense of that observation. 353 00:20:54,795 --> 00:20:57,127 Where Newton space as passive, 354 00:20:57,214 --> 00:21:00,251 Einstein saw it as dynamic. 355 00:21:00,342 --> 00:21:03,834 It's interwoven with time and it dictates how things move. 356 00:21:03,971 --> 00:21:06,383 So after Einstein, 357 00:21:06,515 --> 00:21:10,383 space can no longer be thought of as a static stage. 358 00:21:10,519 --> 00:21:11,599 It's an actor, 359 00:21:11,687 --> 00:21:15,976 and it plays a leading role in the cosmic drama. 360 00:21:22,740 --> 00:21:25,356 Now, it's one thing to think of space 361 00:21:25,493 --> 00:21:28,701 as dynamic, active and flexible like a fabric. 362 00:21:28,788 --> 00:21:30,324 But is it really? 363 00:21:30,414 --> 00:21:32,370 Is this just a metaphor? 364 00:21:32,458 --> 00:21:36,042 Or does it actually describes what space is? 365 00:21:36,170 --> 00:21:39,879 Well, Einstain's theory predicts that one way to find out 366 00:21:40,007 --> 00:21:42,214 would be to take a little journey 367 00:21:42,343 --> 00:21:45,335 to the edge of a black hole. 368 00:21:45,429 --> 00:21:48,216 Black holes are collapsed stars, 369 00:21:48,307 --> 00:21:53,301 massive objects crushed to a fraction of their original size. 370 00:21:53,395 --> 00:21:55,681 Gravity around them is so strong 371 00:21:55,773 --> 00:21:59,391 that according to Einstein's math, a spinning black hole 372 00:21:59,527 --> 00:22:02,815 can literally drag space along with it, 373 00:22:02,905 --> 00:22:06,693 twisting it like an actual piece of cloth. 374 00:22:06,784 --> 00:22:09,696 The nearest black holes is trillions of miles away, 375 00:22:09,787 --> 00:22:13,245 makeing it a challenge to test this prediction. 376 00:22:13,374 --> 00:22:17,367 But in the late 1950s, a physicist named Leonard Schiff 377 00:22:17,461 --> 00:22:18,746 began searching for a way 378 00:22:18,879 --> 00:22:23,919 to test Einstein's ideas about space much closer to home. 379 00:22:24,051 --> 00:22:27,088 Schiff was inspired by something we usually think of 380 00:22:27,221 --> 00:22:30,964 as a child's toy: a gyroscope. 381 00:22:31,100 --> 00:22:35,719 He thought that if space really twists like a fabric, 382 00:22:35,813 --> 00:22:40,933 a gyroscope might allow him to detect it. 383 00:22:41,068 --> 00:22:42,649 It was a strange idea, 384 00:22:42,778 --> 00:22:48,148 and he chose a strange place to share it with the world... 385 00:22:48,284 --> 00:22:51,242 the faculty swimming pool of Stanford. 386 00:22:51,328 --> 00:22:55,867 Here, in 1959, Schiff met 387 00:22:55,958 --> 00:22:58,916 with two collagues,William Fairbank and Bob Cannon. 388 00:22:59,003 --> 00:23:03,997 He was excited about that he'd seen for a high-tech gyroscope. 389 00:23:04,133 --> 00:23:05,168 Though it looked different, 390 00:23:05,301 --> 00:23:07,383 it basically worked the same as the child's toy. 391 00:23:07,469 --> 00:23:08,675 Then and there, 392 00:23:08,804 --> 00:23:13,298 the three decided to launch a device like this into orbit 393 00:23:13,392 --> 00:23:14,598 around th earth. 394 00:23:16,228 --> 00:23:20,392 Normally, a gyroscope's axis points in a fixed direction. 395 00:23:20,482 --> 00:23:23,189 But if Earth is actually dragging space, 396 00:23:23,319 --> 00:23:26,482 then the gyroscope's axis would be dragged along with it, 397 00:23:26,614 --> 00:23:30,323 shifting its orientation in a way that could be measureded. 398 00:23:30,409 --> 00:23:33,822 It was a brilliantly simple plan. 399 00:23:33,954 --> 00:23:36,912 There was just one problem. 400 00:23:36,999 --> 00:23:38,705 Einstein's theories predict 401 00:23:38,834 --> 00:23:43,077 that the earth's rotation twists space by only a tiny amount-- 402 00:23:43,172 --> 00:23:46,505 an amount so small, it would be like trying to measure 403 00:23:46,634 --> 00:23:50,377 the height of a penny from 62 miles away. 404 00:23:53,849 --> 00:23:56,682 The team spent more than two years trying to figure out 405 00:23:56,769 --> 00:23:59,806 how to make such a precise measurement. 406 00:23:59,897 --> 00:24:02,388 They finally devised a plan to attach 407 00:24:02,524 --> 00:24:05,482 four freeli floating gyroscopes to a telescope 408 00:24:05,569 --> 00:24:08,276 aimed at a distant star. 409 00:24:08,364 --> 00:24:11,652 If space twists, then over time, 410 00:24:11,742 --> 00:24:13,698 the gyroscopes would no longer point at the star, 411 00:24:13,786 --> 00:24:17,620 since they'd get caught up in the swirl of space. 412 00:24:17,706 --> 00:24:22,200 And in 1962, they applied to NASA for a grant, 413 00:24:22,294 --> 00:24:24,376 requesting aronnd a million dollars 414 00:24:24,463 --> 00:24:28,627 for what would come to be called Gravity Probe B. 415 00:24:30,219 --> 00:24:31,880 Members of the team originally thought 416 00:24:32,012 --> 00:24:35,254 the project would take about three years. 417 00:24:35,391 --> 00:24:37,848 They were just a little optimistic. 418 00:24:37,935 --> 00:24:40,677 With an over-growing team, Gravity Probe B became 419 00:24:40,771 --> 00:24:44,184 one of the longest-running expriments in history. 420 00:24:44,274 --> 00:24:46,310 Decade affter decade was spent 421 00:24:46,402 --> 00:24:48,984 trying to realize the original vision, 422 00:24:49,071 --> 00:24:51,608 which meant launching a telescope into space 423 00:24:51,740 --> 00:24:53,401 and building gyroscopes 424 00:24:53,492 --> 00:24:57,656 that were among the smoothest objects ever created. 425 00:24:57,746 --> 00:25:00,032 the technology is just frihtening. 426 00:25:00,124 --> 00:25:02,991 It was like the carrot of the front of the mule. 427 00:25:03,085 --> 00:25:05,451 It was like it was always five to ten years away 428 00:25:05,587 --> 00:25:07,418 when we could do this, 429 00:25:07,506 --> 00:25:10,589 and it was five to ten years away far about 35 years. 430 00:25:10,676 --> 00:25:16,091 Consuming more than four decades and $750 million, 431 00:25:16,223 --> 00:25:21,434 the project was nearly cancelled by NASA nine times. 432 00:25:21,520 --> 00:25:24,102 Ten, nine, eight... 433 00:25:24,189 --> 00:25:26,680 Finally, in April of 2004, 434 00:25:26,775 --> 00:25:30,484 the team gathered to witness the launch. 435 00:25:31,488 --> 00:25:34,150 And liftoff! 436 00:25:38,037 --> 00:25:42,201 Of the three men who sat by the pool back in 1959. 437 00:25:42,291 --> 00:25:44,657 only one was alive to see it. 438 00:25:44,793 --> 00:25:46,909 There we were, watching. 439 00:25:47,004 --> 00:25:49,791 It's a terribly exciting moment in your life. 440 00:25:49,882 --> 00:25:55,252 Just a thrilling experience. 441 00:25:55,345 --> 00:25:56,551 It was flawless. 442 00:25:56,638 --> 00:26:00,347 Ten thousand things did not go wrong. 443 00:26:00,476 --> 00:26:04,719 For over a year, Gravity Probe B orbiteb the earth 444 00:26:04,813 --> 00:26:08,226 while the team nervously monitored its every move, 445 00:26:08,317 --> 00:26:12,481 trying to see if the earth would actually twist space. 446 00:26:12,571 --> 00:26:17,110 Finally, the data began to trikle in. 447 00:26:17,201 --> 00:26:18,657 And there was a problem. 448 00:26:18,786 --> 00:26:24,156 The gyroscopes were experiencing a tiny, unexpected wobble, 449 00:26:24,291 --> 00:26:29,081 and to clean up the data would cost millions. 450 00:26:29,171 --> 00:26:31,878 With funds running ant, 451 00:26:32,007 --> 00:26:34,669 it looked like nearly half a century of work 452 00:26:34,802 --> 00:26:37,589 was about to go down the drain. 453 00:26:41,100 --> 00:26:43,716 Then, at almost the last possible moment, 454 00:26:43,852 --> 00:26:46,343 two sources of additional funding emerged: 455 00:26:46,438 --> 00:26:50,306 the son of original team leader William Fairbank, 456 00:26:50,400 --> 00:26:51,856 who made a private donation; 457 00:26:51,944 --> 00:26:55,903 and Turki Al-Saud, a member of the Saudi royal family 458 00:26:56,031 --> 00:26:58,522 with a degree in aeronautics from Stanford, 459 00:26:58,617 --> 00:27:01,654 who arranged for a large grant. 460 00:27:01,745 --> 00:27:03,360 Over the next two years, 461 00:27:03,497 --> 00:27:05,954 the problem with the data was solved, 462 00:27:06,041 --> 00:27:08,703 revealing that the axes of the gyroscopes shifted 463 00:27:08,794 --> 00:27:11,877 by almost exactly the amount predicted 464 00:27:11,964 --> 00:27:14,171 by Einstein's equations. 465 00:27:14,258 --> 00:27:15,668 I think it's the first time 466 00:27:15,759 --> 00:27:20,423 that you can actually see Einstein's effect,his drift, 467 00:27:20,556 --> 00:27:21,716 with the naked eye. 468 00:27:24,810 --> 00:27:29,144 This experiment provides the most direct evidence ever found 469 00:27:29,231 --> 00:27:35,727 that space is something reel a pyhsical entity like a fabric. 470 00:27:35,821 --> 00:27:38,563 After all, if space were nothing, 471 00:27:38,699 --> 00:27:40,564 there would be nothing to twist. 472 00:27:44,955 --> 00:27:48,573 But at the same time that Albert Einstein was investigating space 473 00:27:48,667 --> 00:27:50,658 on the largest of scales, 474 00:27:50,752 --> 00:27:54,085 another band of physicists was probing the universe 475 00:27:54,173 --> 00:27:56,414 on extremely tiny scales. 476 00:27:56,508 --> 00:28:00,000 And there they found a completely uncharted realm 477 00:28:00,095 --> 00:28:02,211 where Einsein's picture of space, 478 00:28:02,306 --> 00:28:04,297 it was nowhere to be found. 479 00:28:04,433 --> 00:28:06,048 To see what I'm talking about, 480 00:28:06,143 --> 00:28:08,930 imagine you could shrink billions of times smaller 481 00:28:09,062 --> 00:28:11,223 than your current size. 482 00:28:13,609 --> 00:28:17,272 This is the realm of atoms and subatomic particles, 483 00:28:17,404 --> 00:28:21,147 the fundamental building blocks of everything we can see. 484 00:28:21,283 --> 00:28:22,898 And when you get down to this size, 485 00:28:22,993 --> 00:28:26,281 the world plays by a wildly different set of rules 486 00:28:26,413 --> 00:28:28,324 calles quantum mechanics. 487 00:28:28,457 --> 00:28:31,290 According to these rules, even if you try to move 488 00:28:31,418 --> 00:28:33,704 every last atom and particle, 489 00:28:33,795 --> 00:28:37,959 you'd find that empty space is still far from empty. 490 00:28:38,050 --> 00:28:41,963 In fact, it's teeming with activity. 491 00:28:42,054 --> 00:28:46,093 Particles are constantly popping in and out of existence. 492 00:28:46,183 --> 00:28:48,765 They erupt out of nothingness, 493 00:28:48,852 --> 00:28:51,468 quickly annihilate each other and disappear. 494 00:28:53,106 --> 00:28:56,269 In quantum mechanics, empty space is not that empty. 495 00:28:56,360 --> 00:28:58,021 it's full of fluctuating fields, 496 00:28:58,153 --> 00:29:01,111 full of all sorts of jittery things going on. 497 00:29:01,198 --> 00:29:02,904 It's a place where particles 498 00:29:02,991 --> 00:29:05,653 are constantly fluctuating and annihilating each ether 499 00:29:05,744 --> 00:29:08,110 and being created again and annihilating. 500 00:29:08,205 --> 00:29:10,992 It's a place of chaos and bubbling. 501 00:29:11,124 --> 00:29:14,992 While the theory predicted this,it wasn't until 1948 502 00:29:15,087 --> 00:29:18,329 that a scientist named Hendrik Casimir suggested 503 00:29:18,423 --> 00:29:21,335 that even though we can't see these particles, 504 00:29:21,468 --> 00:29:24,960 they should cause empty space to do something we can see. 505 00:29:25,055 --> 00:29:26,511 And he predicted 506 00:29:26,640 --> 00:29:29,803 that if you take two ordinary metal plates... 507 00:29:33,230 --> 00:29:35,846 and place them extremely close together 508 00:29:35,941 --> 00:29:39,525 say,closer together than the thickness of a sheet at paper 509 00:29:39,653 --> 00:29:43,111 then particles with certain energies would be excluded 510 00:29:43,198 --> 00:29:48,409 because in same sense, they wouldn't fit between the plates. 511 00:29:48,537 --> 00:29:50,698 With more of this fernetic activity 512 00:29:50,789 --> 00:29:53,030 outside the plates than inside, 513 00:29:53,166 --> 00:29:55,873 Casimir thought the plates would be pushed together 514 00:29:56,003 --> 00:29:59,996 by what we usually think of as empty space. 515 00:30:00,090 --> 00:30:02,251 And some years later, when the experiment was done... 516 00:30:10,142 --> 00:30:12,133 Casimir was proven right. 517 00:30:12,227 --> 00:30:15,014 In empty space, the plates were pushed together. 518 00:30:15,105 --> 00:30:19,394 So on atomic scales,empty space is not empty. 519 00:30:19,484 --> 00:30:21,395 It's so flooded with activity 520 00:30:21,528 --> 00:30:24,065 that it can force objects to move. 521 00:30:26,533 --> 00:30:27,693 And today, 522 00:30:27,784 --> 00:30:31,072 the quest to understand space on the smallest scale is continuing 523 00:30:31,163 --> 00:30:35,122 with one of the most expensive science experiments in history. 524 00:30:36,835 --> 00:30:38,791 This is CERN, 525 00:30:38,920 --> 00:30:42,788 the European Organization for Nuclear Research in Geneva. 526 00:30:42,924 --> 00:30:46,416 And here, buried a few hundred feet below the ground, 527 00:30:46,511 --> 00:30:47,842 is the Large Hadron Collider, 528 00:30:47,929 --> 00:30:51,296 the world's most powerful accelerator. 529 00:30:51,433 --> 00:30:54,721 With a price tag of about $10 billion, 530 00:30:54,811 --> 00:30:57,177 it accelerates subatomic particles 531 00:30:57,272 --> 00:31:00,514 to more than 99.99% of the speed of light 532 00:31:00,609 --> 00:31:03,396 and smashes them into each other. 533 00:31:03,487 --> 00:31:06,024 In the showers of debris produced by these collisions, 534 00:31:06,114 --> 00:31:09,777 scientists at placess like this have discovered a whole zoo 535 00:31:09,910 --> 00:31:12,617 of strange and exotic particles. 536 00:31:12,746 --> 00:31:16,489 And right now, they are chasing one of the most elusive, 537 00:31:16,625 --> 00:31:21,460 a particle thought to be essential to shaping everything 538 00:31:21,588 --> 00:31:28,209 from the atoms in our bodies to the most distant stars. 539 00:31:28,303 --> 00:31:30,168 If this particle is found, 540 00:31:30,305 --> 00:31:33,593 it will redefine our picture of space 541 00:31:33,683 --> 00:31:36,049 and fulfill a quest begun more than 40 years ago. 542 00:31:39,898 --> 00:31:43,891 It all started in 1964, 543 00:31:43,985 --> 00:31:47,022 when a young English physicist named Peter Higgs 544 00:31:47,155 --> 00:31:49,988 suggested something about space that was so radical, 545 00:31:50,117 --> 00:31:53,484 it nearly ruined him. 546 00:31:53,578 --> 00:31:56,786 HIGGS: I was told that I was talking nonsense, 547 00:31:56,873 --> 00:32:01,037 that I couldn't be right. 548 00:32:01,169 --> 00:32:04,753 So they clearly hadn't understand what I was saying. 549 00:32:04,840 --> 00:32:07,172 GREENE:Higgs and a few others 550 00:32:07,300 --> 00:32:10,007 were wrestling with a puzzle which comes down to this: 551 00:32:10,095 --> 00:32:12,131 The fundamental particles in the universe 552 00:32:12,222 --> 00:32:15,305 all contain different amounts of mass, 553 00:32:15,392 --> 00:32:18,930 which we usually think of as weight. 554 00:32:19,020 --> 00:32:23,013 Without mass, these particles would never combine 555 00:32:23,150 --> 00:32:26,813 to form the familliar atoms that make up all the stuff 556 00:32:26,903 --> 00:32:28,689 we see in the world around us. 557 00:32:30,866 --> 00:32:33,528 But what creates mass? 558 00:32:33,660 --> 00:32:36,367 And why do different particles have different masses? 559 00:32:36,455 --> 00:32:38,696 Try as they might, 560 00:32:38,832 --> 00:32:41,699 no one had been able to answer this perplexing question. 561 00:32:41,793 --> 00:32:45,035 Then, one weekend, 562 00:32:45,172 --> 00:32:50,166 after a walk outside Edinbugh, Higgs had a peculiar idea. 563 00:32:50,260 --> 00:32:53,047 Using mathematics, he imagined space in a new way, 564 00:32:53,138 --> 00:32:55,094 as something like an ocean. 565 00:32:55,223 --> 00:32:58,306 Particles are immersed in this ocean 566 00:32:58,393 --> 00:33:01,476 and gain mass as they move through it. 567 00:33:01,563 --> 00:33:04,270 To see how this works, 568 00:33:04,399 --> 00:33:09,063 think of a particle's mass like an actor's fame, 569 00:33:09,154 --> 00:33:12,442 and the Higgs ocean is like the paparazzi. 570 00:33:12,574 --> 00:33:16,817 Some particles, like unknown actors, pass through with ease. 571 00:33:16,912 --> 00:33:19,654 The paparazzi simply aren't interested in them. 572 00:33:19,748 --> 00:33:22,831 But other particles, like superstars, 573 00:33:22,918 --> 00:33:25,159 have to push and press. 574 00:33:25,253 --> 00:33:28,745 And the more those particles struggle to get through, 575 00:33:28,882 --> 00:33:31,043 the more they interact with the ocean, 576 00:33:31,134 --> 00:33:34,092 and the more mass they gain. 577 00:33:34,221 --> 00:33:39,056 Higgs was convinced he'd made a great discovery. 578 00:33:39,142 --> 00:33:43,476 But when he submitted his idea to a journal at CERN, 579 00:33:43,605 --> 00:33:46,597 it was rejected. 580 00:33:46,733 --> 00:33:50,817 Undaunted, Higgs honed his theory further 581 00:33:50,946 --> 00:33:53,779 until he was offered the chance to present it 582 00:33:53,907 --> 00:33:55,693 at Einstein's old haunt: 583 00:33:55,784 --> 00:33:59,322 the Institute for Advanced Study in Princeton. 584 00:33:59,454 --> 00:34:02,617 There,he expected his new idea 585 00:34:02,749 --> 00:34:04,489 would meet some of its toughest critics. 586 00:34:07,712 --> 00:34:09,828 HIGGS:I was happily driving up the freeway. 587 00:34:09,965 --> 00:34:12,297 and then there was a sign to turn off for Princeton, 588 00:34:12,425 --> 00:34:16,134 and that really confronted me with what I was going into. 589 00:34:16,221 --> 00:34:19,179 I broke out in a cold sweat and started trembling, 590 00:34:19,307 --> 00:34:23,926 and I had to pull off the road to recover. 591 00:34:24,020 --> 00:34:25,009 GREENE: But Higgs persevered. 592 00:34:25,146 --> 00:34:27,853 It was the first in a series of talks 593 00:34:27,983 --> 00:34:31,146 that would convinse colleagues far and wide 594 00:34:31,236 --> 00:34:34,399 that he was onto something profound. 595 00:34:34,489 --> 00:34:37,481 HIGGS: Eventually I sort of wore them down. 596 00:34:37,617 --> 00:34:40,324 I felt I had sort of triumphed. 597 00:34:42,330 --> 00:34:45,447 So I enjoyed the parties which followed. 598 00:34:45,542 --> 00:34:51,003 GREENE: Today, the idea Higgs pioneered calles the Higgs field. 599 00:34:51,131 --> 00:34:53,668 is crucial to our understanding of space. 600 00:34:53,800 --> 00:34:56,007 LYKKEN: The Higgs field is everywhere. 601 00:34:56,136 --> 00:34:58,878 It's something that, even in the emptiest vacuum of space, 602 00:34:59,014 --> 00:35:01,255 has an effect: it gives you mass. 603 00:35:01,349 --> 00:35:04,091 So I think Higgs actually deserves credit 604 00:35:04,185 --> 00:35:08,178 for being one of the people that said space is stuff, 605 00:35:08,273 --> 00:35:11,265 it had properties in it that are intrinsic, 606 00:35:11,359 --> 00:35:13,771 that you can't get rid of, you can't turn them off. 607 00:35:13,862 --> 00:35:15,853 GREENE: The only problem? 608 00:35:15,947 --> 00:35:19,656 There's no physical proof that the Higgs field exeits, 609 00:35:19,743 --> 00:35:21,404 at least not yet. 610 00:35:21,536 --> 00:35:23,117 But here at CERN, 611 00:35:23,204 --> 00:35:26,321 scientists are attempting to smash particles together 612 00:35:26,416 --> 00:35:29,203 with so much energy 613 00:35:29,294 --> 00:35:31,785 that they will knock loose a piece of the Higgs filed... 614 00:35:33,757 --> 00:35:36,715 producing a tiny particle of its own. 615 00:35:36,801 --> 00:35:43,548 It's as if they're trying to chip off off a piece of space. 616 00:35:43,642 --> 00:35:46,099 We think that if we knock into space hard enough 617 00:35:46,227 --> 00:35:48,218 with particle accelerator collisions, 618 00:35:48,313 --> 00:35:50,554 that we can actually make a Higgs particle 619 00:35:50,649 --> 00:35:52,389 come out of empty space. 620 00:35:52,484 --> 00:35:54,975 Our whole understanding of matter as we now have it 621 00:35:55,070 --> 00:36:01,407 would just fall apart if the Higgs field didn't exist. 622 00:36:01,534 --> 00:36:03,741 I don't think anybody seriously doubts that we will see it. 623 00:36:03,870 --> 00:36:07,203 Certainly if we don't,that will be an extremely bizarre outcome. 624 00:36:07,290 --> 00:36:11,374 GREENE: Finding the Higgs particle would be a major milestone 625 00:36:11,461 --> 00:36:14,874 establishing that the emptiest of the empty space 626 00:36:14,964 --> 00:36:18,252 has an impact on all of matter. 627 00:36:18,385 --> 00:36:21,252 But it turns out that space contains an ingredient 628 00:36:21,388 --> 00:36:24,755 far more elusive than anything Higgs ever imagined, 629 00:36:24,849 --> 00:36:26,965 an ingredient that may hold the key 630 00:36:27,102 --> 00:36:29,263 to the greatest of all mysteries, 631 00:36:29,396 --> 00:36:33,560 the very fate of the cosmos. 632 00:36:33,650 --> 00:36:37,984 It's a mystery that began some 14 billion years ago 633 00:36:38,113 --> 00:36:42,777 in what we call the Big Bang. 634 00:36:42,909 --> 00:36:44,240 In a fraction of a second, 635 00:36:44,327 --> 00:36:47,069 the universe underwent a violent expansion, 636 00:36:47,163 --> 00:36:49,449 sending space hurtling outward. 637 00:36:52,168 --> 00:36:56,207 Space has been expanding ever since. 638 00:36:56,297 --> 00:36:59,255 For decades, most scientists thought that expansion 639 00:36:59,342 --> 00:37:04,086 must be slowing down thanks to the pull of gravity. 640 00:37:04,180 --> 00:37:05,795 When I toss an apple up, 641 00:37:05,890 --> 00:37:08,973 the gravity of the earth eventually stops it 642 00:37:09,060 --> 00:37:11,722 and brings it back. 643 00:37:11,813 --> 00:37:13,678 And just like the apple slows down with time, 644 00:37:13,815 --> 00:37:16,978 so too the universe should have been slowing down 645 00:37:17,110 --> 00:37:20,819 in its expansion because of the gravitational attraction 646 00:37:20,905 --> 00:37:24,318 of all matter and energy for all other matter and energy 647 00:37:24,451 --> 00:37:27,363 GREENE:But that raised the question: 648 00:37:27,495 --> 00:37:30,077 what is the ultimate fate of the cosmos? 649 00:37:30,165 --> 00:37:33,077 Would space go on expanding forever, 650 00:37:33,168 --> 00:37:37,036 or would gravity eventually stop space time expanding, 651 00:37:37,172 --> 00:37:41,006 cauing it to collapse back on itself in a "big crunch"? 652 00:37:43,636 --> 00:37:46,503 To solve this mystery, two team of astronomer 653 00:37:46,639 --> 00:37:48,971 set out to measure the slowing of the expansion 654 00:37:49,058 --> 00:37:51,014 using a novel tool, 655 00:37:51,144 --> 00:37:54,978 exploding stars called supernovas. 656 00:37:57,901 --> 00:38:00,438 ADAM RIESS:So a supernova is a star 657 00:38:00,528 --> 00:38:03,019 that ends its life in a massive explosion. 658 00:38:03,156 --> 00:38:05,522 They're extremely luminous. 659 00:38:05,658 --> 00:38:07,944 They can be as bright as a billion suns. 660 00:38:10,538 --> 00:38:11,948 SAUL PESLMUTTER:What makes supernova great 661 00:38:12,040 --> 00:38:13,905 is that they are very similar when they explode. 662 00:38:14,042 --> 00:38:15,953 They all get to about the same brightness 663 00:38:16,044 --> 00:38:18,160 and then they fade away in just about the same way. 664 00:38:21,966 --> 00:38:25,959 GREENE:Because the explosions are so bright and uniform. 665 00:38:26,054 --> 00:38:28,170 the teams reasoned that these supernovas 666 00:38:28,264 --> 00:38:30,505 would act as very precise cosmic beacons, 667 00:38:30,600 --> 00:38:33,763 allowing them to track how the expansion of space 668 00:38:33,895 --> 00:38:36,557 has slowed over time. 669 00:38:36,689 --> 00:38:40,557 The trouble is, supernovas are extremely rare. 670 00:38:40,693 --> 00:38:43,275 To find enough of them, 671 00:38:43,404 --> 00:38:47,147 Perlmutter spent years calling astronmers around the globe, 672 00:38:47,242 --> 00:38:49,153 begging for time on their telescopes. 673 00:38:49,244 --> 00:38:52,907 We needed the biggest telescopes in the world. 674 00:38:52,997 --> 00:38:54,737 We needed perfect conditions. 675 00:38:54,833 --> 00:38:56,118 And in those perfect conditions, 676 00:38:56,251 --> 00:38:58,617 I would be calling people up at the middle of their night 677 00:38:58,753 --> 00:39:01,415 when they're tring to do some serious work, 678 00:39:01,506 --> 00:39:02,871 and I'd be saying, 679 00:39:02,966 --> 00:39:04,581 "I know that you have a very busy schedule, 680 00:39:04,717 --> 00:39:05,832 "but by any chance, 681 00:39:05,927 --> 00:39:08,464 "if you could just squeeze in this half-hour observation, 682 00:39:08,596 --> 00:39:10,257 it would really be very interesting to us." 683 00:39:10,390 --> 00:39:13,507 GREENE:When they finally had enough data 684 00:39:13,601 --> 00:39:15,762 to chart how much the pull of gravity 685 00:39:15,895 --> 00:39:17,806 was slowing the expansion of the universe, 686 00:39:17,939 --> 00:39:20,521 they were in for a surprise. 687 00:39:20,608 --> 00:39:22,690 PERTMUTTER: The results looked a little bit strange. 688 00:39:22,777 --> 00:39:25,234 They didn't really show any slowing of the universe at all. 689 00:39:25,321 --> 00:39:26,936 Very surprising. 690 00:39:27,073 --> 00:39:30,941 Actually,a universe that's actually speeding up. 691 00:39:31,035 --> 00:39:34,619 It was as thought space,which we really thought was nothinng, 692 00:39:34,706 --> 00:39:37,823 actually had an inherent springiness to it. 693 00:39:37,959 --> 00:39:40,450 And so space did not want to be compressed; 694 00:39:40,587 --> 00:39:43,203 space actually wants to push the uninverse apart. 695 00:39:43,298 --> 00:39:45,209 It looked like the universe 696 00:39:45,300 --> 00:39:48,542 was expanding fastar and fastar with time, 697 00:39:48,636 --> 00:39:52,470 accelerating rather than decelerating. 698 00:39:52,557 --> 00:39:54,764 My immediate response was, 699 00:39:54,851 --> 00:39:56,682 "I have to figure out why this is wrong. 700 00:39:56,811 --> 00:39:57,891 This can't be right." 701 00:39:57,979 --> 00:40:00,345 GREENE: But it was right. 702 00:40:00,481 --> 00:40:04,190 And most scientists converged on one explanation: 703 00:40:04,319 --> 00:40:06,651 There's something that fills space 704 00:40:06,738 --> 00:40:10,481 and counteracts the pull of ordinary attractive gravity, 705 00:40:10,575 --> 00:40:12,657 pushing galaxies apart 706 00:40:12,744 --> 00:40:17,864 and stretching the very fabric of the cosmos. 707 00:40:17,999 --> 00:40:21,082 This mysterious substance filling space 708 00:40:21,169 --> 00:40:24,582 has been dubbed"dark energy," 709 00:40:24,672 --> 00:40:29,587 and it's turned our picture of the universe upside down. 710 00:40:29,677 --> 00:40:31,838 FILIPPENKO: Over the largest distances, 711 00:40:31,930 --> 00:40:35,843 dark energy dominates the contents of the uninverse, 712 00:40:35,934 --> 00:40:39,222 and we don't know what it is. 713 00:40:39,354 --> 00:40:41,891 GATES: If you do sort of a survey, 714 00:40:42,023 --> 00:40:44,685 a census of all the enrgy in the universe 715 00:40:44,817 --> 00:40:50,028 dark energy turns out to be about 70% of the universe. 716 00:40:50,114 --> 00:40:52,651 And up until a decade ago, 717 00:40:52,742 --> 00:40:55,984 nobody imagined such stuff even existed. 718 00:40:56,079 --> 00:41:00,413 GREENE:So in essence, the weight of empty space itself 719 00:41:00,541 --> 00:41:04,375 is 70% of the weight of the entire universe. 720 00:41:04,504 --> 00:41:07,371 Thet's roughly the same percentage of Earth's surface 721 00:41:07,465 --> 00:41:09,706 that's covered by watter. 722 00:41:09,801 --> 00:41:12,463 Imagine we didn't know what water is. 723 00:41:12,553 --> 00:41:16,296 That's where we stand with dark enengy. 724 00:41:16,391 --> 00:41:19,474 LYKKEN:We're really clueless about how to explain it. 725 00:41:19,560 --> 00:41:21,892 We have all of this fancy scientific apparatus 726 00:41:22,021 --> 00:41:24,512 of quantum mechanics and relativity and particle physics 727 00:41:24,607 --> 00:41:26,723 that we've developed in the last hundred years, 728 00:41:26,818 --> 00:41:30,060 and none of that works to explain dark energy. 729 00:41:32,281 --> 00:41:36,775 GREENE: And the discovery of dark energy held another surprise: 730 00:41:36,911 --> 00:41:41,746 The idea that the universe contains such an"ingredient" 731 00:41:41,874 --> 00:41:46,368 had actually been "cooked up" 80 years earlier. 732 00:41:46,462 --> 00:41:48,919 GREENE: I'll let you in on a little secret. 733 00:41:49,048 --> 00:41:50,913 Although he didn't call it dark energy, 734 00:41:51,050 --> 00:41:54,213 long ago,Albert Einstein prediceted that space itself 735 00:41:54,303 --> 00:41:58,717 could exert a force that would drive galaxies apart. 736 00:41:58,808 --> 00:42:00,093 You see, 737 00:42:00,184 --> 00:42:04,302 shortly after discovering his general theory of relativity, 738 00:42:04,439 --> 00:42:06,225 his theory of gravity, 739 00:42:06,315 --> 00:42:09,057 Einstein found that, according to the mathematics, 740 00:42:09,152 --> 00:42:16,524 the universe would either be expanding or contracting. 741 00:42:16,617 --> 00:42:18,858 But it couldn't hover at a fixed size. 742 00:42:18,953 --> 00:42:23,617 This was puzzling because before they knew about the Big Bang, 743 00:42:23,708 --> 00:42:26,450 most scientists, including Einstein, 744 00:42:26,586 --> 00:42:31,296 pictured the universe as static: eternal and unchanging. 745 00:42:31,382 --> 00:42:33,794 When Einstein's equations 746 00:42:33,885 --> 00:42:36,968 suggested an expanding or contracting universe-- 747 00:42:37,055 --> 00:42:39,797 not the static universe everyone believed in-- 748 00:42:39,932 --> 00:42:42,298 he had a problem. 749 00:42:42,393 --> 00:42:44,759 So Einstein went back to his equations 750 00:42:44,854 --> 00:42:48,688 and modified them to allow for a kind of anti-gravity 751 00:42:48,816 --> 00:42:51,808 that would infuse space with an outward push, 752 00:42:51,944 --> 00:42:54,310 counteracting the usual inward pull of gravity, 753 00:42:54,405 --> 00:42:57,818 alowing the universe to stand still. 754 00:42:57,950 --> 00:43:01,317 He called the modification the cosmological constant. 755 00:43:01,454 --> 00:43:06,323 Adding the cosmological constant rescued his equations. 756 00:43:06,417 --> 00:43:12,003 But the truth is, Einstein had no idea if this outward push, 757 00:43:12,131 --> 00:43:15,168 or anti-gravity,really existed. 758 00:43:15,259 --> 00:43:17,841 The introduction of the cosmological constant 759 00:43:17,929 --> 00:43:21,842 by Einstein was not a very elegant solution 760 00:43:21,974 --> 00:43:23,839 to try to find what he was looking for: 761 00:43:23,976 --> 00:43:25,682 a stationary universe. 762 00:43:25,812 --> 00:43:27,848 It achieves this effect of anti-gravity. 763 00:43:27,980 --> 00:43:30,471 It says that gravity sometimes can behave in such a way 764 00:43:30,566 --> 00:43:33,023 as not to pull things together but to push things apart. 765 00:43:33,152 --> 00:43:34,767 Like the clash of two titans, 766 00:43:34,862 --> 00:43:38,195 the cosmological constant and the pull of ordinary matter 767 00:43:38,282 --> 00:43:41,695 could hold the universe in check and keep it static. 768 00:43:41,786 --> 00:43:46,155 But about a dozen years later,the astronomer Edwin Hubble 769 00:43:46,249 --> 00:43:49,207 discovered the universe is not static. 770 00:43:49,293 --> 00:43:53,127 It's expanding due to the explosive force of the Big Bang 771 00:43:53,214 --> 00:43:54,829 140 billion years ago. 772 00:43:58,219 --> 00:44:00,380 That meant Einstein's original equations 773 00:44:00,471 --> 00:44:04,089 no longer had to be altered. 774 00:44:04,225 --> 00:44:07,717 And so suddenly,the need for a cosmological constant 775 00:44:07,854 --> 00:44:09,845 went right out the window. 776 00:44:15,236 --> 00:44:16,396 Thank you. 777 00:44:16,529 --> 00:44:17,860 You're welcome. 778 00:44:17,947 --> 00:44:21,064 Einstein is said to have called this his biggest blunder. 779 00:44:21,200 --> 00:44:23,407 But here's the thing. 780 00:44:23,536 --> 00:44:25,197 With the recent discovery 781 00:44:25,288 --> 00:44:28,246 that the expansion of the universe is accelerating, 782 00:44:28,374 --> 00:44:31,161 scientists are convinced that there is something in space 783 00:44:31,252 --> 00:44:33,083 that is pushing things apart. 784 00:44:33,171 --> 00:44:36,083 So 70 years later,Einstein's biggest blunder 785 00:44:36,215 --> 00:44:40,584 may rank among his greastest insights. 786 00:44:40,720 --> 00:44:43,427 It was something that nobody else was thinking about. 787 00:44:43,514 --> 00:44:47,302 But it might be that Einstein's cosmological constant is the key 788 00:44:47,435 --> 00:44:49,050 to understanding the expansion of the universe 789 00:44:49,145 --> 00:44:50,430 as we see it today. 790 00:44:50,521 --> 00:44:55,732 GREENE: Though no one knows what dark energy actually is, 791 00:44:55,818 --> 00:44:59,902 it raises an astounding and troubling possibility. 792 00:44:59,989 --> 00:45:04,232 Einstein pictured the strength of his anti-gravity as constant, 793 00:45:04,327 --> 00:45:08,366 but is the strength of dark energy constant? 794 00:45:08,456 --> 00:45:11,789 And what if it changes over time? 795 00:45:11,876 --> 00:45:15,869 The answer could overturn everything we thought we knew 796 00:45:15,963 --> 00:45:19,376 about the fate of the cosmos. 797 00:45:19,467 --> 00:45:21,674 At the moment,everything in our world, 798 00:45:21,802 --> 00:45:24,293 from the molecules making up my body 799 00:45:24,388 --> 00:45:26,629 to the molecules making up the room, 800 00:45:26,766 --> 00:45:28,848 is held together by forces 801 00:45:28,976 --> 00:45:31,638 that overwhelm the outward push of dark energy. 802 00:45:31,729 --> 00:45:34,562 And that's why we don't see things expanding 803 00:45:34,649 --> 00:45:36,435 in our everyday lives. 804 00:45:36,525 --> 00:45:39,858 But that situation might not last forever. 805 00:45:39,987 --> 00:45:43,479 In one scenario, 806 00:45:43,574 --> 00:45:46,737 dark energy will continue to push the galaxies 807 00:45:46,827 --> 00:45:51,491 farther and farther apart until ultimately, 808 00:45:51,582 --> 00:45:53,288 they'd be pushed so far apart 809 00:45:53,376 --> 00:45:59,042 that the universe would become a cold,dark and lonely place. 810 00:46:02,343 --> 00:46:03,879 In another scenario, 811 00:46:04,011 --> 00:46:07,128 the strength of dark energy might increase over time, 812 00:46:07,223 --> 00:46:10,090 becoming so strong that it would tear apart everything 813 00:46:10,184 --> 00:46:11,344 within the galaxies, 814 00:46:11,477 --> 00:46:19,395 from stars,to planets,to matter of all kind. 815 00:46:24,740 --> 00:46:27,698 If the dark energy grows with time, 816 00:46:27,785 --> 00:46:32,529 then ultimately even atoms will get ripped apart 817 00:46:32,623 --> 00:46:35,706 when there's enough dark energy between the nuclear 818 00:46:35,835 --> 00:46:38,542 and the electrons to rip space apart. 819 00:46:38,671 --> 00:46:39,911 The Big Rip. 820 00:46:48,097 --> 00:46:49,337 Our picture of space 821 00:46:49,432 --> 00:46:52,549 has gone through a remarkable transformation. 822 00:46:52,643 --> 00:46:56,807 Back in Newton's time,space was just the container. 823 00:46:56,897 --> 00:47:00,890 It didn't do anything at all. 824 00:47:01,027 --> 00:47:02,142 Then through Einstein, 825 00:47:02,236 --> 00:47:06,570 space begans to effect how objects move. 826 00:47:06,699 --> 00:47:10,692 Then with Casimir literally objects can be pushed 827 00:47:10,786 --> 00:47:13,653 by the activity even in empty space. 828 00:47:17,752 --> 00:47:20,585 And now, through the ideas of Higgs and dark energy, 829 00:47:20,671 --> 00:47:24,414 the very expansion of the universe may be coming 830 00:47:24,508 --> 00:47:29,593 from the energy of empty space itself. 831 00:47:29,722 --> 00:47:31,428 I don't think anybody would have thought 832 00:47:31,557 --> 00:47:35,220 that space would have this kind of rich and profound impact 833 00:47:35,311 --> 00:47:37,222 on the nature of reality. 834 00:47:40,232 --> 00:47:42,018 But as far as we're come, 835 00:47:42,109 --> 00:47:46,273 the journey that began with Isaac Newton's picture of space 836 00:47:46,364 --> 00:47:51,609 as something like a stage is not yet finished. 837 00:47:51,702 --> 00:47:55,490 As we examine the fabric of the cosmos more closely, 838 00:47:55,623 --> 00:47:58,865 we may well find far more surprises 839 00:47:58,959 --> 00:48:01,291 than anyone ever imagined. 840 00:48:03,255 --> 00:48:06,122 Take me, for example. 841 00:48:06,217 --> 00:48:11,007 I seem real enough,don't I? 842 00:48:11,138 --> 00:48:13,094 Well, yes. 843 00:48:13,182 --> 00:48:16,140 But surprising new clues are emerging that everything-- 844 00:48:16,227 --> 00:48:18,718 you and I and even space itself-- 845 00:48:18,813 --> 00:48:20,019 may actually be... 846 00:48:23,484 --> 00:48:25,099 a kind of hologram. 847 00:48:25,194 --> 00:48:29,153 That is, everything we see and experience, 848 00:48:29,240 --> 00:48:34,109 everything we call our familiar 849 00:48:34,203 --> 00:48:38,162 may be a projection of information that's stored 850 00:48:38,290 --> 00:48:41,327 on a thin, distant, two-dimensional surface, 851 00:48:41,460 --> 00:48:44,918 sort of the way the information for this hologram 852 00:48:45,005 --> 00:48:48,543 is stored on this thin piece of plastic. 853 00:48:48,676 --> 00:48:51,668 Now, holograms are something we're all familiar with 854 00:48:51,762 --> 00:48:55,801 from the security symbol you find on most credit cards. 855 00:48:58,227 --> 00:49:00,934 But the universe as a hologram? 856 00:49:01,021 --> 00:49:03,182 That's one of the most drastic revisions 857 00:49:03,315 --> 00:49:07,024 to our picture of space,and reality,ever proposed. 858 00:49:07,153 --> 00:49:08,689 And the evidence for it 859 00:49:08,779 --> 00:49:13,239 comes from some of the strangest realms of space:black holes. 860 00:49:13,367 --> 00:49:16,234 This is a real disconnect 861 00:49:16,370 --> 00:49:18,031 and it's very hard to get your head around. 862 00:49:21,250 --> 00:49:24,538 Modern ideas coming from black holes 863 00:49:24,628 --> 00:49:29,497 tell us that reality is two-dimensional, 864 00:49:29,592 --> 00:49:31,548 that the three-dimensional world, 865 00:49:31,677 --> 00:49:33,884 the full-bodied,three-dimensional world 866 00:49:34,013 --> 00:49:36,129 is a kind of image of a hologram 867 00:49:36,223 --> 00:49:39,715 on the boundary of the region of space. 868 00:49:39,810 --> 00:49:41,892 This is a very strange thing. 869 00:49:41,979 --> 00:49:45,688 When I was a younger physicist,I would have thought 870 00:49:45,774 --> 00:49:49,312 any physicist who said that was absolutely crazy. 871 00:49:49,403 --> 00:49:52,440 Here's a way to think about this. 872 00:49:52,573 --> 00:49:57,112 Imagine I took my wallet and threw it into a black hole. 873 00:49:57,244 --> 00:49:59,200 What would happen? 874 00:49:59,288 --> 00:50:03,497 We used to think that since nothing,not even light, 875 00:50:03,584 --> 00:50:06,451 can escape the immense gravity of the black hole 876 00:50:06,587 --> 00:50:10,205 my wallet would be lost forever 877 00:50:10,299 --> 00:50:15,009 but it now seems that may not be the whole story. 878 00:50:15,095 --> 00:50:19,088 Recently, scientists exploring the math describing black holes 879 00:50:19,183 --> 00:50:21,765 made a curious discovery 880 00:50:21,852 --> 00:50:25,094 Even as my wallet disappears into the black hole, 881 00:50:25,231 --> 00:50:28,098 a copy of all the information it contains 882 00:50:28,234 --> 00:50:31,943 seems to get smeared out and stored on the surface 883 00:50:32,029 --> 00:50:34,315 of the black hole in much the same way 884 00:50:34,448 --> 00:50:38,612 that information is stored in a computer. 885 00:50:38,702 --> 00:50:42,945 So in the and, my wallett exists in two places: 886 00:50:43,040 --> 00:50:46,453 there's a three-dimensianal version that's lost forever 887 00:50:46,585 --> 00:50:50,203 inside the black hole, and a two-dimensianal version 888 00:50:50,297 --> 00:50:54,085 that remains on the surface as information. 889 00:50:54,176 --> 00:50:56,918 CLIFFORD IOHNSON: the information content of all the stuff 890 00:50:57,012 --> 00:51:00,470 that fell into that black hole can be expressed 891 00:51:00,599 --> 00:51:03,466 entirely in terms of just the outside of the black hole. 892 00:51:03,602 --> 00:51:06,969 The idea then is that you can capture 893 00:51:07,106 --> 00:51:09,472 what's going on inside the black hole 894 00:51:09,608 --> 00:51:12,475 by referring only to the outside. 895 00:51:12,611 --> 00:51:16,149 And in theory, I could use the information 896 00:51:16,240 --> 00:51:20,904 on the outside of the black hole to reconstruct my wallet. 897 00:51:20,995 --> 00:51:24,487 And here's the truly mind-blowing part: 898 00:51:24,582 --> 00:51:27,745 Space within a black hole plays by the same rules 899 00:51:27,835 --> 00:51:31,669 as space outside a black hole or anywhere else. 900 00:51:31,797 --> 00:51:34,834 So if an object inside a black hole 901 00:51:34,967 --> 00:51:37,834 can be described by information on the black hole's surface, 902 00:51:37,970 --> 00:51:41,383 then it might be that everything in the universe-- 903 00:51:41,515 --> 00:51:46,760 from galaxies and stars to you and me, even space itself-- 904 00:51:46,854 --> 00:51:49,846 is just a projection of information stored 905 00:51:49,940 --> 00:51:53,853 on some distant, two-dimensional surface that surrounds us. 906 00:51:53,986 --> 00:51:57,444 In other words, what we experience as reality 907 00:51:57,531 --> 00:52:01,023 may be something like a hologram. 908 00:52:01,160 --> 00:52:03,776 Is the three-dimensional world an illusion 909 00:52:03,871 --> 00:52:07,989 in the same sense that a hologram is an illusion? 910 00:52:08,083 --> 00:52:09,744 Perhaps. 911 00:52:09,877 --> 00:52:11,913 I think I'm inclined to think," Yes", 912 00:52:12,046 --> 00:52:14,378 that the three-dimensional world is a kind of illusion 913 00:52:14,506 --> 00:52:17,873 and that the ultimate precise reality 914 00:52:17,968 --> 00:52:22,632 is the two-dimensional reality of the surface of the universe. 915 00:52:22,723 --> 00:52:27,342 This idea is so new that physicists are still struggling 916 00:52:27,436 --> 00:52:29,301 to understand it 917 00:52:29,396 --> 00:52:31,853 But if it's right, just as Newton and Einstein 918 00:52:31,940 --> 00:52:34,477 conpletely changed our picture of space, 919 00:52:34,568 --> 00:52:39,232 we may on the verge of an even more dramatic revolution. 920 00:52:39,323 --> 00:52:41,405 For something that's such a vital part 921 00:52:41,533 --> 00:52:43,273 of our everyday lives, 922 00:52:43,410 --> 00:52:46,402 space remains kind of like a familiar stranger. 923 00:52:46,497 --> 00:52:48,909 It's all arounnd ns, 924 00:52:48,999 --> 00:52:53,618 but we're still far from having unmassked its true identity. 925 00:52:53,754 --> 00:52:58,373 That may take a hundred years, it may take a thousand years, 926 00:52:58,467 --> 00:53:00,799 or it may happen tomorrow. 927 00:53:00,928 --> 00:53:03,715 But when we solve that mystery, 928 00:53:03,806 --> 00:53:06,593 we'll take a giant step toward fully understanding 929 00:53:06,725 --> 00:53:09,512 the fabric of the cosmos. 930 00:53:27,621 --> 00:53:30,112 Major funding for NOVA is provided by: 931 00:53:32,584 --> 00:53:33,915 And... 932 00:53:44,722 --> 00:53:48,135 And by the Corporation for Public Broadcasting 933 00:53:48,225 --> 00:53:52,343 and by contributions to your PBS station from: 934 00:53:59,027 --> 00:54:01,689 Major funding for" The Fabric at the Cosmos" 935 00:54:01,822 --> 00:54:04,734 is provided by the National Science Foundation. 936 00:54:12,166 --> 00:54:13,656 And... 937 00:54:17,337 --> 00:54:19,749 Supporting original research and public understanding 938 00:54:19,840 --> 00:54:26,131 of science, technology, engineering and mathematics. 939 00:54:26,221 --> 00:54:28,086 Additional funding is provided by... 940 00:54:39,443 --> 00:54:41,775 And the George D. Smith Fund. 941 00:54:44,406 --> 00:54:47,113 Captioned by Media Access Group at WGBH access.wgbh.org