1 00:00:03,233 --> 00:00:04,533 Narrator: THE MILKY WAY... 2 00:00:06,600 --> 00:00:10,867 ...AN EMPIRE OF OVER 200 BILLION STARS. 3 00:00:10,867 --> 00:00:14,000 Oluseyi: THE EARTH IS OUR HOME. THE SUN IS OUR STAR. 4 00:00:14,000 --> 00:00:15,400 AND THE MILKY WAY IS OUR GALAXY. 5 00:00:15,400 --> 00:00:18,167 IT'S US. IT'S OUR HOME. 6 00:00:18,167 --> 00:00:21,100 Narrator: BUT WHERE DID IT ALL COME FROM? 7 00:00:21,100 --> 00:00:23,533 Thaller: WHY DO GALAXIES FORM AT ALL? 8 00:00:23,533 --> 00:00:25,967 SOMETHING HAS TO HAPPEN. SOMETHING HAS TO MIX THINGS UP. 9 00:00:28,067 --> 00:00:31,100 Narrator: SO WHAT SPARKED OUR GALAXY INTO LIFE? 10 00:00:34,400 --> 00:00:38,467 NEW RESEARCH SUGGESTS AN UNLIKELY HERO. 11 00:00:38,467 --> 00:00:42,133 Krauss: AT THE CENTER OF OUR GALAXY IS A MASSIVE BLACK HOLE. 12 00:00:42,133 --> 00:00:44,000 AND BY MASSIVE, I MEAN REALLY MASSIVE. 13 00:00:44,000 --> 00:00:47,100 Plait: EVEN THOUGH THIS THING IS TERRIFYING, 14 00:00:47,100 --> 00:00:48,300 OUR GALAXY DEPENDS ON IT. 15 00:00:48,300 --> 00:00:50,767 Narrator: COULD THIS MONSTER, 16 00:00:50,767 --> 00:00:53,500 THE GREAT DESTROYER OF THE UNIVERSE, 17 00:00:53,500 --> 00:00:57,033 ACTUALLY BE A GREAT CREATOR? 18 00:00:57,033 --> 00:01:01,067 COULD A BLACK HOLE HAVE BUILT OUR HOME, THE MILKY WAY? 19 00:01:01,067 --> 00:01:02,800 Krauss: THE BLACK HOLE MAY BE RESPONSIBLE 20 00:01:02,800 --> 00:01:04,300 FOR THE BEGINNING OF OUR GALAXY, 21 00:01:04,300 --> 00:01:07,300 AND IT'LL DEFINITELY ULTIMATELY BE RESPONSIBLE FOR ITS DEATH. 22 00:01:07,300 --> 00:01:10,300 -- Captions by VITAC -- www.vitac.com 23 00:01:10,300 --> 00:01:13,333 CAPTIONS PAID FOR BY DISCOVERY COMMUNICATIONS 24 00:01:20,300 --> 00:01:23,067 Narrator: LOOK AROUND THE UNIVERSE, 25 00:01:23,067 --> 00:01:26,567 AND YOU'LL SEE GALAXIES OF EVERY KIND, 26 00:01:26,567 --> 00:01:30,833 A KALEIDOSCOPIC ARRAY OF UNIQUE SHAPES AND SIZES. 27 00:01:33,267 --> 00:01:37,467 THESE GRAND GALACTIC STRUCTURES FILL THE COSMOS. 28 00:01:37,467 --> 00:01:41,700 Plait: THE BASIC BUILDING BLOCK OF THE UNIVERSE IS THE GALAXY, 29 00:01:41,700 --> 00:01:44,933 AND THERE ARE HUNDREDS OF BILLIONS OF GALAXIES 30 00:01:44,933 --> 00:01:46,800 IN THE UNIVERSE. 31 00:01:46,800 --> 00:01:48,900 THE SAME WAY THAT CELLS MAKE UP YOUR BODY 32 00:01:48,900 --> 00:01:50,400 OR BRICKS MAKE UP A BUILDING, 33 00:01:50,400 --> 00:01:52,333 GALAXIES MAKE UP THE UNIVERSE. 34 00:01:54,667 --> 00:01:58,233 Narrator: WE SHOULD THANK OUR LUCKY STARS FOR GALAXIES. 35 00:01:58,233 --> 00:02:01,300 Thaller: GALAXIES ARE THE ONLY PLACE IN THE UNIVERSE 36 00:02:01,300 --> 00:02:02,933 WHERE STARS AND PLANETS FORM. 37 00:02:02,933 --> 00:02:06,067 WE DON'T SEE STARS OUT BETWEEN THE GALAXIES. 38 00:02:06,067 --> 00:02:07,300 THIS IS THE ONLY PLACE 39 00:02:07,300 --> 00:02:09,567 WHERE THE HYDROGEN IS BROUGHT TOGETHER, 40 00:02:09,567 --> 00:02:12,167 HEATED UP, AND A GENERATION OF LIFE CAN BEGIN. 41 00:02:14,067 --> 00:02:17,767 Narrator: THERE ARE HUNDREDS OF BILLIONS OF GALAXIES IN THE UNIVERSE, 42 00:02:17,767 --> 00:02:21,200 BUT ONLY ONE GAVE BIRTH TO US. 43 00:02:21,200 --> 00:02:26,133 I SOMETIMES ASK MY STUDENTS TO IDENTIFY WHERE THEY LIVE. 44 00:02:26,133 --> 00:02:30,867 WELL, YOU WOULD SAY, FOR EXAMPLE, "NEW YORK CITY," 45 00:02:30,867 --> 00:02:34,433 "THE US OF A," "PLANET EARTH," 46 00:02:34,433 --> 00:02:37,133 "THIRD PLANET FROM THE SUN." 47 00:02:37,133 --> 00:02:40,633 AND THEN, YOU WOULD SAY "THE MILKY WAY GALAXY." 48 00:02:44,633 --> 00:02:46,967 THE MILKY WAY GALAXY IS OUR HOME. 49 00:02:49,200 --> 00:02:51,133 Narrator: BECAUSE WE SEE IT FROM WITHIN, 50 00:02:51,133 --> 00:02:56,067 ALL WE SEE IS A BAND OF STARS STRETCHED ACROSS THE SKY. 51 00:02:56,067 --> 00:02:58,867 BUT VIEWED FROM OUTSIDE, 52 00:02:58,867 --> 00:03:03,233 WE'D SEE A SPECTACULAR GIANT SPIRAL GALAXY 53 00:03:03,233 --> 00:03:06,667 MADE UP OF OVER 200 BILLION STARS. 54 00:03:08,667 --> 00:03:13,267 OUR SUN IS JUST A DOT WITHIN ONE OF ITS ENORMOUS ARMS. 55 00:03:13,267 --> 00:03:17,100 Plait: OUR MILKY WAY GALAXY IS HUGE. 56 00:03:17,100 --> 00:03:20,267 IT'S ACTUALLY ONE OF THE BIGGEST GALAXIES IN THE UNIVERSE, AS A MATTER OF FACT. 57 00:03:20,267 --> 00:03:22,867 I'D PROBABLY PUT IT IN THE TOP 10% CERTAINLY. 58 00:03:22,867 --> 00:03:27,600 Narrator: MASSIVE, MAGNIFICENT. 59 00:03:27,600 --> 00:03:32,333 OUR GALAXY HAS LONG HIDDEN ITS SECRETS AT ITS HEART. 60 00:03:32,333 --> 00:03:36,400 THE GREATEST QUESTION -- HOW DID IT FORM? 61 00:03:36,400 --> 00:03:40,767 AT STAKE IS NOT JUST THE ANSWER TO THE ORIGINS OF OUR GALAXY, 62 00:03:40,767 --> 00:03:43,967 BUT THE ORIGINS OF OUR SOLAR SYSTEM, 63 00:03:43,967 --> 00:03:48,800 OUR STAR, THE SUN, AND ULTIMATELY, US. 64 00:03:48,800 --> 00:03:52,233 THE MILKY WAY'S PAST AND THE WHOLE STORY 65 00:03:52,233 --> 00:03:54,900 LEADS US TO WHERE WE ARE NOW AND WHO WE ARE NOW. 66 00:03:56,967 --> 00:03:59,733 Narrator: SO WHAT CREATED THE MILKY WAY, 67 00:03:59,733 --> 00:04:01,300 AND HOW DID IT GROW 68 00:04:01,300 --> 00:04:04,467 INTO THE MAJESTIC GALAXY WE SEE TODAY? 69 00:04:08,067 --> 00:04:09,267 TO ANSWER THAT, 70 00:04:09,267 --> 00:04:12,700 WE HAVE TO TRAVEL BACK TO THE INFANT UNIVERSE, 71 00:04:12,700 --> 00:04:15,167 TO JUST AFTER THE BIG BANG. 72 00:04:20,700 --> 00:04:24,233 13.6 BILLION YEARS AGO, 73 00:04:24,233 --> 00:04:28,067 THERE ARE NO STARS, NO PLANETS... 74 00:04:28,067 --> 00:04:30,433 AND NO GALAXIES. 75 00:04:30,433 --> 00:04:33,700 Bullock: HOW DO WE GO FROM THAT EARLY UNIVERSE 76 00:04:33,700 --> 00:04:35,867 THAT'S ALMOST PERFECTLY, PERFECTLY FEATURELESS 77 00:04:35,867 --> 00:04:37,900 TO THIS COMPLEX AND VERY INTERESTING UNIVERSE 78 00:04:37,900 --> 00:04:39,167 THAT WE SEE AROUND US TODAY? 79 00:04:41,267 --> 00:04:45,433 Narrator: THE EARLY UNIVERSE IS A THICK, UNIFORM SOUP OF GAS 80 00:04:45,433 --> 00:04:48,100 WITH SOME TINY IRREGULARITIES. 81 00:04:48,100 --> 00:04:53,967 BUT IT'S ENOUGH TO SET GRAVITY TO WORK, PULLING GAS TOGETHER. 82 00:04:55,633 --> 00:04:58,867 Kaku: GRAVITY KEEPS ON COMPRESSING THE GAS DOWN TO A POINT. 83 00:04:58,867 --> 00:05:01,967 AND THAT'S WHEN TEMPERATURES RISE DRAMATICALLY 84 00:05:01,967 --> 00:05:04,333 TO 50- TO 100-MILLION DEGREES. 85 00:05:04,333 --> 00:05:06,633 AT THAT POINT, YOU GET IGNITION. 86 00:05:06,633 --> 00:05:11,733 AT THAT POINT, HYDROGEN FUSES INTO HELIUM, AND WE GET A STAR. 87 00:05:11,733 --> 00:05:15,733 A STAR IS BORN. 88 00:05:17,967 --> 00:05:20,133 Narrator: IN THIS THEORY, 89 00:05:20,133 --> 00:05:24,500 NOT ONE, BUT MILLIONS OF STARS BURST INTO LIFE. 90 00:05:26,800 --> 00:05:30,200 SLOWLY, GRAVITY BRINGS THEM TOGETHER. 91 00:05:30,200 --> 00:05:33,400 AFTER A FEW MILLION YEARS, 92 00:05:33,400 --> 00:05:37,467 THEY FORM A ROTATING SPHERE OF STARS, 93 00:05:37,467 --> 00:05:40,433 AND A GALAXY IS BORN. 94 00:05:40,433 --> 00:05:44,267 THERE'S A PROBLEM, THOUGH. 95 00:05:44,267 --> 00:05:46,867 THERE'S TOO MUCH GRAVITY. 96 00:05:46,867 --> 00:05:49,833 SOMETHING OTHER THAN JUST THE STARS 97 00:05:49,833 --> 00:05:52,300 MUST BE HOLDING THEM TOGETHER. 98 00:05:52,300 --> 00:05:54,967 BUT WHAT IS IT? 99 00:05:54,967 --> 00:06:01,367 TURNS OUT, THE ANSWER LIES AT THE CENTER OF OUR OWN GALAXY. 100 00:06:03,433 --> 00:06:05,100 Thaller: AT THE VERY HEART OF THE MILKY WAY, 101 00:06:05,100 --> 00:06:08,067 YOU SEE STARS ORBITING SOMETHING THAT ISN'T THERE. 102 00:06:08,067 --> 00:06:10,333 AND IF YOU DO THE CALCULATIONS, 103 00:06:10,333 --> 00:06:13,233 THE AMOUNT OF MASS NEEDED AT THE VERY CENTER 104 00:06:13,233 --> 00:06:17,133 IS ABOUT FOUR MILLION TIMES THE MASS OF OUR SUN. 105 00:06:17,133 --> 00:06:19,767 SO STARS ARE BASICALLY ORBITING LIKE PLANETS 106 00:06:19,767 --> 00:06:22,067 AROUND THIS EMPTY OBJECT 107 00:06:22,067 --> 00:06:24,067 WITH FOUR MILLION TIMES THE MASS OF THE SUN. 108 00:06:26,600 --> 00:06:29,500 Narrator: THIS OBJECT MUST BE COLOSSAL. 109 00:06:29,500 --> 00:06:32,867 IT MUST BE UNIMAGINABLY DENSE. 110 00:06:32,867 --> 00:06:36,567 IT COULD ONLY BE ONE THING -- 111 00:06:36,567 --> 00:06:39,333 A BLACK HOLE, 112 00:06:39,333 --> 00:06:42,167 A SUPERMASSIVE BLACK HOLE. 113 00:06:44,900 --> 00:06:46,967 Kaku: IF THE MOON GOES AROUND THE EARTH, 114 00:06:46,967 --> 00:06:49,733 AND THE EARTH GOES AROUND THE SUN, 115 00:06:49,733 --> 00:06:52,767 THEN WHAT DOES THE SUN GO AROUND? 116 00:06:52,767 --> 00:06:55,500 THE SUN GOES AROUND A MASSIVE BLACK HOLE 117 00:06:55,500 --> 00:06:58,133 AT THE CENTER OF THE GALAXY. 118 00:06:58,133 --> 00:07:00,767 Narrator: WITHIN THE MILKY WAY, 119 00:07:00,767 --> 00:07:05,300 SCIENTISTS FIND THEIR FIRST SUPERMASSIVE BLACK HOLE. 120 00:07:05,300 --> 00:07:07,933 BUT IT WASN'T THE LAST. 121 00:07:07,933 --> 00:07:11,333 TURNS OUT, THEY'RE EVERYWHERE. 122 00:07:11,333 --> 00:07:14,700 Plait: WE KNOW THAT MOST BIG GALAXIES 123 00:07:14,700 --> 00:07:17,733 HAVE A SUPERMASSIVE BLACK HOLE RIGHT IN THEIR CENTER. 124 00:07:17,733 --> 00:07:20,367 THAT'S TELLING US THAT THESE TWO THINGS ARE RELATED. 125 00:07:20,367 --> 00:07:22,867 THEY COME AS A PAIR. 126 00:07:22,867 --> 00:07:27,533 SOMEHOW, THE BLACK HOLES AND THE GALAXIES 127 00:07:27,533 --> 00:07:29,600 AND THEIR ORIGIN AND EVOLUTION ARE TIED TOGETHER. 128 00:07:32,133 --> 00:07:34,333 Narrator: AMAZINGLY, THE MILKY WAY, 129 00:07:34,333 --> 00:07:37,800 THIS SPARKLING EXPANSE OF STARS, 130 00:07:37,800 --> 00:07:39,867 IS ALL INTRINSICALLY LINKED 131 00:07:39,867 --> 00:07:41,533 TO THE DARKEST 132 00:07:41,533 --> 00:07:45,200 AND MOST ENIGMATIC ENTITY IN THE UNIVERSE -- 133 00:07:45,200 --> 00:07:48,100 A SUPERMASSIVE BLACK HOLE. 134 00:07:48,100 --> 00:07:50,800 IT IS AN OBJECT OF TREMENDOUS FASCINATION AND MYSTERY. 135 00:07:50,800 --> 00:07:52,267 HOW DID IT GET THERE? 136 00:07:52,267 --> 00:07:54,233 HOW DID IT GROW TO BE SO LARGE? 137 00:07:54,233 --> 00:07:56,600 IS IT GONNA CONTINUE TO GROW? 138 00:07:56,600 --> 00:08:00,533 Narrator: TO FIGURE OUT THE ORIGINS OF OUR GALAXY, 139 00:08:00,533 --> 00:08:04,400 WE MUST FIRST FIND OUT HOW IT GOT ITS BLACK HOLE. 140 00:08:11,533 --> 00:08:16,067 IN THE EARLY UNIVERSE, THE FIRST STARS BURST INTO LIFE. 141 00:08:19,900 --> 00:08:24,200 BUT THESE STARS, THEY'RE NOTHING LIKE OUR SUN. 142 00:08:24,200 --> 00:08:27,633 Wechsler: THOSE FIRST STARS WERE VERY, VERY MASSIVE. 143 00:08:27,633 --> 00:08:30,667 AND ONE OF THE THINGS THAT HAPPENS WITH MASSIVE STARS 144 00:08:30,667 --> 00:08:32,067 IS THEY EXPLODE QUICKLY. 145 00:08:35,533 --> 00:08:37,967 Narrator: IN JUST A FEW HUNDRED MILLION YEARS, 146 00:08:37,967 --> 00:08:42,167 THE BIGGEST BURN THROUGH THEIR HYDROGEN FUEL... 147 00:08:42,167 --> 00:08:44,200 AND DIE. 148 00:08:49,633 --> 00:08:51,333 Plait: THEY WOULD'VE EXPLODED 149 00:08:51,333 --> 00:08:54,567 AS INCREDIBLY POWERFUL SUPERNOVAE, EXPLODING STARS. 150 00:08:54,567 --> 00:08:57,433 THEIR CORES WOULD'VE COLLAPSED TO FORM BLACK HOLES, 151 00:08:57,433 --> 00:08:58,800 AND THIS MAY HAVE BEEN 152 00:08:58,800 --> 00:09:01,200 THE VERY FIRST BLACK HOLES THAT FORMED IN THE UNIVERSE. 153 00:09:04,667 --> 00:09:07,300 Narrator: THESE BLACK HOLES WOULD START SMALL. 154 00:09:07,300 --> 00:09:09,800 OVER BILLIONS OF YEARS, 155 00:09:09,800 --> 00:09:13,067 ONE WOULD EAT AND GROW INTO THE MONSTER 156 00:09:13,067 --> 00:09:16,833 THAT NOW SITS AT THE HEART OF OUR GALAXY. 157 00:09:19,133 --> 00:09:23,500 IT'S A SOLID THEORY, BUT THERE'S A PROBLEM. 158 00:09:23,500 --> 00:09:26,900 ASTRONOMERS FIND SUPER-BRIGHT LIGHTS 159 00:09:26,900 --> 00:09:29,733 IN THE VERY EARLY UNIVERSE. 160 00:09:34,300 --> 00:09:37,400 THESE AREN'T STARS. 161 00:09:37,400 --> 00:09:40,067 THEY'RE CALLED QUASARS. 162 00:09:40,067 --> 00:09:44,700 Kaku: QUASARS ARE THE BAD BOYS OF ASTRONOMY. 163 00:09:44,700 --> 00:09:47,067 WHEN WE FIRST FOUND THEM, WE WERE PUZZLED, 164 00:09:47,067 --> 00:09:50,633 BECAUSE HOW CAN AN OBJECT EMIT SO MUCH ENERGY? 165 00:09:50,633 --> 00:09:56,933 THE ENERGY OUTPUT IS SUFFICIENT TO LIGHT UP THE ENTIRE UNIVERSE. 166 00:09:59,700 --> 00:10:01,167 Narrator: THESE QUASARS, 167 00:10:01,167 --> 00:10:03,667 THOUGH SMALLER THAN OUR SOLAR SYSTEM, 168 00:10:03,667 --> 00:10:08,000 SOMEHOW OUTSHINE 100 GALAXIES PUT TOGETHER. 169 00:10:14,667 --> 00:10:18,533 Krauss: THE ENERGY EMITTED VASTLY EXCEEDS THE ENERGY IN A STAR. 170 00:10:18,533 --> 00:10:21,433 THE ONLY PROCESS WE KNOW 171 00:10:21,433 --> 00:10:23,467 THAT WOULD PRODUCE THAT KIND OF ENERGY 172 00:10:23,467 --> 00:10:25,967 IS THE COLLAPSE OF HUGE AMOUNTS OF MATTER 173 00:10:25,967 --> 00:10:27,300 INTO A MASSIVE BLACK HOLE. 174 00:10:30,167 --> 00:10:33,100 WE REALIZED, "OH, MY GOD. 175 00:10:33,100 --> 00:10:37,467 THESE ARE, IN FACT, HUGE, RAGING BLACK HOLES." 176 00:10:37,467 --> 00:10:39,233 Narrator: THEY'RE MUCH BIGGER 177 00:10:39,233 --> 00:10:44,033 THAN THOSE MADE AT THE END OF A STAR'S LIFE. 178 00:10:44,033 --> 00:10:46,467 WE'RE NOT JUST TALKING ABOUT A STELLAR MASS BLACK HOLE, 179 00:10:46,467 --> 00:10:49,867 WHICH MIGHT HAVE 5 OR 10 OR 20 TIMES THE MASS OF THE SUN. 180 00:10:49,867 --> 00:10:51,767 WE'RE TALKING ABOUT A TRUE MONSTER 181 00:10:51,767 --> 00:10:55,233 THAT HAS MILLIONS OR BILLIONS OF TIMES THE MASS OF THE SUN. 182 00:10:57,800 --> 00:11:00,067 Narrator: SO WHERE DO THESE BLACK HOLES COME FROM? 183 00:11:02,100 --> 00:11:07,933 THEY'RE WAY TOO BIG TO BE THE RESULT OF EARLY EXPLODING STARS. 184 00:11:07,933 --> 00:11:11,600 THEY HAVE TO BE FORMED IN ANOTHER WAY. 185 00:11:11,600 --> 00:11:14,500 THE THEORY THAT STARS FORMED FIRST, 186 00:11:14,500 --> 00:11:17,200 CONVERGING TO BUILD GALAXIES, 187 00:11:17,200 --> 00:11:20,267 NEEDS A RADICAL OVERHAUL. 188 00:11:20,267 --> 00:11:24,600 INSTEAD, DOES THE BLACK HOLE COME FIRST? 189 00:11:24,600 --> 00:11:28,467 IS IT THE MOTHER OF ALL CREATION, 190 00:11:28,467 --> 00:11:34,400 GIVING BIRTH TO THE MILKY WAY, THE STARS, AND US? 191 00:11:43,800 --> 00:11:45,767 Narrator: THE MILKY WAY, 192 00:11:45,767 --> 00:11:50,933 OUR VAST, INCANDESCENT GALAXY, HAS A HEART OF DARKNESS. 193 00:11:50,933 --> 00:11:56,300 BUT WHICH CAME FIRST -- THE LIGHT OR THE DARK? 194 00:11:56,300 --> 00:11:59,633 Thaller: IT'S ALMOST SORT OF LIKE A CHICKEN AND AN EGG. 195 00:11:59,633 --> 00:12:01,900 WHICH CAME FIRST, THE GALAXY OR THE BLACK HOLE? 196 00:12:01,900 --> 00:12:05,133 Krauss: DO YOU NEED A BLACK HOLE TO MAKE A GALAXY, 197 00:12:05,133 --> 00:12:07,700 OR DO YOU NEED A LARGE GALAXY TO MAKE A LARGE BLACK HOLE? 198 00:12:07,700 --> 00:12:10,167 Kaku: DID THE BLACK HOLE COME FIRST? 199 00:12:10,167 --> 00:12:13,367 OR DID THE STARS AND THE GALAXY COME FIRST? 200 00:12:17,133 --> 00:12:19,600 Narrator: IN ONE THEORY, STARS COME FIRST. 201 00:12:19,600 --> 00:12:22,567 THE BIGGEST DIE, 202 00:12:22,567 --> 00:12:26,233 CREATING A BLACK HOLE DURING THEIR DEATH THROES. 203 00:12:30,300 --> 00:12:33,833 BUT THE DISCOVERY OF QUASARS CHALLENGES THIS. 204 00:12:33,833 --> 00:12:36,333 THERE ARE SUPERMASSIVE BLACK HOLES 205 00:12:36,333 --> 00:12:38,267 AT THE VERY START OF THE UNIVERSE, 206 00:12:38,267 --> 00:12:42,700 FAR TOO LARGE TO BE THE REMNANTS OF THE FIRST STARS. 207 00:12:44,700 --> 00:12:47,467 SO WHERE DO THEY COME FROM? 208 00:12:47,467 --> 00:12:51,167 AND COULD THEY GO ON TO CREATE GALAXIES? 209 00:12:55,967 --> 00:13:00,367 ENTER THE NEW THEORY OF DIRECT COLLAPSE. 210 00:13:00,367 --> 00:13:03,967 Bullock: IN THIS THEORY, IN THE VERY EARLY UNIVERSE, 211 00:13:03,967 --> 00:13:05,800 YOU HAVE A GIANT GAS CLOUD 212 00:13:05,800 --> 00:13:08,633 THAT COLLAPSES STRAIGHT INTO A BLACK HOLE. 213 00:13:10,600 --> 00:13:13,067 Narrator: IT'S JUST LIKE THE BIRTH OF A STAR, 214 00:13:13,067 --> 00:13:17,067 BUT THE STAR DIES BEFORE IT'S BORN. 215 00:13:17,067 --> 00:13:19,800 THE THEORY GOES LIKE THIS. 216 00:13:19,800 --> 00:13:23,433 CLOUDS OF GAS CLUMP TOGETHER. 217 00:13:23,433 --> 00:13:27,200 THEY SPIRAL INTO A CENTRAL POINT, 218 00:13:27,200 --> 00:13:29,233 BECOMING INCREDIBLY DENSE. 219 00:13:29,233 --> 00:13:34,433 AT THIS POINT IN STAR FORMATION, THE CORE WOULD IGNITE. 220 00:13:34,433 --> 00:13:38,100 BUT HERE, TOO MUCH GAS AND DUST IS PILED IN. 221 00:13:38,100 --> 00:13:41,200 THE MASS OF IT ALL IS SO GREAT 222 00:13:41,200 --> 00:13:44,367 THAT GRAVITY BECOMES UNSTOPPABLE. 223 00:13:46,500 --> 00:13:50,967 IT CRUSHES THE GAS, MAKING IT DENSER AND DENSER, 224 00:13:50,967 --> 00:13:54,167 UNTIL IT REACHES ITS BREAKING POINT. 225 00:13:54,167 --> 00:13:59,600 FINALLY, THE GAS COLLAPSES... 226 00:13:59,600 --> 00:14:05,533 SO VIOLENTLY, IT RIPS THROUGH THE FABRIC OF SPACE. 227 00:14:05,533 --> 00:14:10,400 A MASSIVE BLACK HOLE IS BORN. 228 00:14:10,400 --> 00:14:12,500 I'M TALKING ABOUT MAKING A BLACK HOLE THAT'S WAY BIGGER 229 00:14:12,500 --> 00:14:13,633 THAN ANY KIND OF BLACK HOLE 230 00:14:13,633 --> 00:14:15,333 THAT WOULD FORM AT THE END OF A STAR'S LIFE. 231 00:14:17,633 --> 00:14:20,700 Narrator: THIS COULD EXPLAIN HOW THE BLACK HOLES AND QUASARS 232 00:14:20,700 --> 00:14:24,433 ARE SO HUGE SO EARLY ON IN THE UNIVERSE. 233 00:14:26,400 --> 00:14:31,733 IF TRUE, THEN IT MIGHT BE BLACK HOLES COME FIRST, BEFORE STARS. 234 00:14:33,667 --> 00:14:36,767 BUT FOR NOW, IT'S JUST A THEORY. 235 00:14:41,733 --> 00:14:46,333 THE JURY IS STILL OUT AS TO HOW OUR GALAXY FIRST FORMS. 236 00:14:49,400 --> 00:14:51,600 Krauss: THE CHICKEN-AND-EGG QUESTION IS, 237 00:14:51,600 --> 00:14:54,067 DO BLACK HOLES CAUSE THE GALAXIES 238 00:14:54,067 --> 00:14:55,967 TO COIL US AROUND THEM, 239 00:14:55,967 --> 00:15:00,467 OR DO THE GALAXIES BUILD UP AND HIT SOME CRUCIAL, CRITICAL SIZE, 240 00:15:00,467 --> 00:15:03,633 BEYOND WHICH BLACK HOLES MUST FORM AT THEIR CENTER? 241 00:15:03,633 --> 00:15:04,833 AND WE WANT TO LEARN ABOUT THAT. 242 00:15:04,833 --> 00:15:06,233 AND THE ONLY WAY TO LEARN ABOUT 243 00:15:06,233 --> 00:15:08,233 THAT IS TO LOOK OUT IN THE UNIVERSE AND TRY AND FIND OUT. 244 00:15:10,267 --> 00:15:11,667 Narrator: TO PROVE ONE OF OUR THEORIES, 245 00:15:11,667 --> 00:15:15,500 WE NEED OBSERVATIONAL EVIDENCE. 246 00:15:15,500 --> 00:15:19,267 AND A SMALL DWARF GALAXY MIGHT PROVIDE IT. 247 00:15:19,267 --> 00:15:22,467 HENIZE 2-10 IS YOUNG. 248 00:15:22,467 --> 00:15:26,600 MANY OF ITS STARS ARE JUST A FEW MILLION YEARS OLD. 249 00:15:26,600 --> 00:15:29,067 IT MIGHT PROVIDE US A LOOK BACK 250 00:15:29,067 --> 00:15:32,900 AT OUR MILKY WAY IN ITS INFANT YEARS. 251 00:15:32,900 --> 00:15:37,400 HENIZE 2-10 IS A VERY INTERESTING, TINY DWARF GALAXY. 252 00:15:37,400 --> 00:15:40,700 ORIGINALLY, I WAS STUDYING THIS GALAXY 253 00:15:40,700 --> 00:15:43,100 BECAUSE IT HAS ALL THIS STAR FORMATION GOING ON. 254 00:15:43,100 --> 00:15:45,833 BUT WHEN I STARTED LOOKING AT ALL OF THE DATA, 255 00:15:45,833 --> 00:15:48,600 I WAS SORT OF SHOCKED AND VERY EXCITED. 256 00:15:48,600 --> 00:15:51,500 I FOUND A SUPERMASSIVE BLACK HOLE 257 00:15:51,500 --> 00:15:53,067 AT THE CENTER OF THIS LITTLE GALAXY. 258 00:15:55,767 --> 00:15:59,433 Narrator: FINDING A BLACK HOLE IN A GALAXY IS NOTHING NEW, 259 00:15:59,433 --> 00:16:02,267 BUT THE REAL DISCOVERY 260 00:16:02,267 --> 00:16:06,100 IS THE SIZE OF THIS MONSTER BLACK HOLE. 261 00:16:08,733 --> 00:16:12,400 OUR BEST ESTIMATE FOR THE MASS OF THE BLACK HOLE IN HENIZE 2-10 262 00:16:12,400 --> 00:16:15,467 IS A MILLION OR TWO SOLAR MASSES. 263 00:16:15,467 --> 00:16:18,600 NOW, THIS IS COMPARABLE TO THE MASS OF THE BLACK HOLE 264 00:16:18,600 --> 00:16:20,300 IN OUR OWN MILKY WAY GALAXY. 265 00:16:20,300 --> 00:16:23,433 BUT THE MILKY WAY IS 100,000 LIGHT-YEARS ACROSS, 266 00:16:23,433 --> 00:16:27,333 WHEREAS HENIZE 2-10 IS ONLY A FEW THOUSAND LIGHT-YEARS ACROSS. 267 00:16:27,333 --> 00:16:30,967 IT'S AMAZING TO FIND A BLACK HOLE 268 00:16:30,967 --> 00:16:34,067 THAT IS SO MASSIVE IN A SMALL DWARF GALAXY. 269 00:16:34,067 --> 00:16:37,333 Narrator: BEFORE THIS DISCOVERY, 270 00:16:37,333 --> 00:16:40,433 SCIENTISTS DIDN'T THINK SUCH A TINY GALAXY 271 00:16:40,433 --> 00:16:43,267 COULD CONTAIN SUCH A COLOSSUS. 272 00:16:43,267 --> 00:16:46,533 Reines: THIS IS COMPLETELY UNEXPECTED. 273 00:16:46,533 --> 00:16:48,700 USUALLY, SUPERMASSIVE BLACK HOLES ARE FOUND 274 00:16:48,700 --> 00:16:51,600 IN MUCH LARGER, MUCH MORE MASSIVE GALAXIES. 275 00:16:51,600 --> 00:16:55,733 Narrator: AMY'S DISCOVERY IS GROUNDBREAKING. 276 00:16:55,733 --> 00:16:58,767 IN HENIZE 2-10, 277 00:16:58,767 --> 00:17:02,800 THE BLACK HOLE IS MORE DEVELOPED THAN THE GALAXY. 278 00:17:02,800 --> 00:17:07,333 IT'S EVIDENCE SUGGESTING THE BLACK HOLE IS OLDER, 279 00:17:07,333 --> 00:17:10,933 THAT IT CAME FIRST. 280 00:17:10,933 --> 00:17:14,733 COULD THIS BE THE SAME FOR OTHER GALAXIES? 281 00:17:14,733 --> 00:17:18,667 Reines: HOW MANY DWARF GALAXIES HOST MASSIVE BLACK HOLES? 282 00:17:18,667 --> 00:17:21,133 IS HENIZE 2-10 A UNIQUE CASE, 283 00:17:21,133 --> 00:17:23,767 OR ARE THERE LOTS OF OTHER EXAMPLES? 284 00:17:23,767 --> 00:17:26,133 WE'VE SEARCHED THROUGH THE SLOAN DIGITAL SKY SURVEY 285 00:17:26,133 --> 00:17:29,333 AND FOUND OVER 100 MORE DWARF GALAXIES 286 00:17:29,333 --> 00:17:31,767 THAT HAVE SUPERMASSIVE BLACK HOLES. 287 00:17:33,700 --> 00:17:37,100 Narrator: HENIZE 2-10 COULD BE A BLUEPRINT 288 00:17:37,100 --> 00:17:39,867 FOR HOW ALL GALAXIES FIRST FORMED, 289 00:17:39,867 --> 00:17:44,233 INCLUDING OUR OWN GALAXY, THE MILKY WAY. 290 00:17:46,400 --> 00:17:49,433 IT'S FASCINATING, BECAUSE IT COULD BE THE EVIDENCE THAT 291 00:17:49,433 --> 00:17:51,167 THE BIG BLACK HOLES FORM FIRST, 292 00:17:51,167 --> 00:17:53,167 AND THEN, THE GALAXIES FORM AROUND THEM. 293 00:17:55,600 --> 00:17:57,767 Narrator: EVERYTHING WE SEE IN OUR SKY -- 294 00:17:57,767 --> 00:18:01,967 THE STARS, OUR SUN, 295 00:18:01,967 --> 00:18:06,067 THE PLANETS, OUR WHOLE GALAXY -- 296 00:18:06,067 --> 00:18:10,667 MIGHT ALL HAVE STARTED AS A SUPERMASSIVE BLACK HOLE. 297 00:18:10,667 --> 00:18:14,767 BUT HOW DO YOU GO FROM THIS 298 00:18:14,767 --> 00:18:20,633 TO SOMETHING AS GLORIOUS AS THE MILKY WAY WE SEE TODAY? 299 00:18:20,633 --> 00:18:23,567 WHERE DO THE STARS COME FROM? 300 00:18:33,600 --> 00:18:35,600 Narrator: 13 BILLION YEARS AGO, 301 00:18:35,600 --> 00:18:37,900 THE MILKY WAY MAY HAVE STARTED LIFE 302 00:18:37,900 --> 00:18:41,500 AS A SUPERMASSIVE BLACK HOLE, 303 00:18:41,500 --> 00:18:44,900 A HUGE SPHERE OF BLACK 304 00:18:44,900 --> 00:18:48,567 SURROUNDED BY A MAELSTROM OF GAS AND DUST. 305 00:18:48,567 --> 00:18:52,067 THIS IS OUR GALAXY. 306 00:18:52,067 --> 00:18:55,333 BUT HOW DO YOU GO FROM THIS 307 00:18:55,333 --> 00:18:59,067 TO THE SHIMMERING SWEEP OF STARS WE SEE TODAY? 308 00:19:03,067 --> 00:19:04,600 Plait: PEOPLE THINK OF BLACK HOLES 309 00:19:04,600 --> 00:19:06,900 AS BEING GIGANTIC COSMIC VACUUM CLEANERS 310 00:19:06,900 --> 00:19:08,367 THAT SUCK EVERYTHING DOWN. 311 00:19:08,367 --> 00:19:09,700 THAT'S NOT REALLY TRUE. 312 00:19:09,700 --> 00:19:11,300 IF YOU GET TOO CLOSE TO ONE, 313 00:19:11,300 --> 00:19:13,800 YEAH, YOU CAN FALL IN, AND YOU'LL NEVER GET BACK OUT. 314 00:19:13,800 --> 00:19:16,567 BUT THEY CAN BE A FORCE FOR CREATION, AS WELL. 315 00:19:16,567 --> 00:19:21,200 Narrator: HOW CAN A BLACK HOLE BE CREATIVE? 316 00:19:21,200 --> 00:19:25,400 ONE CLUE -- BLACK HOLES AREN'T JUST BLACK. 317 00:19:25,400 --> 00:19:27,533 FAR FROM IT. 318 00:19:27,533 --> 00:19:29,433 Bullock: YOU CAN THINK OF BLACK HOLES 319 00:19:29,433 --> 00:19:31,800 AS ONE OF THE BIGGEST PARADOXES IN THE UNIVERSE. 320 00:19:31,800 --> 00:19:33,900 THEY'RE BLACK, SO THEY DON'T EMIT ANY LIGHT. 321 00:19:33,900 --> 00:19:35,233 BUT THEY CAN CAUSE 322 00:19:35,233 --> 00:19:37,267 SOME OF THE BRIGHTEST THINGS IN THE ENTIRE UNIVERSE. 323 00:19:39,500 --> 00:19:42,733 Narrator: QUASARS PROVE THAT THESE MASSIVE BLACK HOLES 324 00:19:42,733 --> 00:19:46,200 THROW OUT MORE LIGHT THAN WHOLE GALAXIES. 325 00:19:48,700 --> 00:19:51,967 BLACK HOLES DON'T JUST SWALLOW MATTER. 326 00:19:51,967 --> 00:19:54,500 THEY ALSO SPIT IT OUT. 327 00:19:54,500 --> 00:19:58,533 Oluseyi: A SUPERMASSIVE BLACK HOLE IS A MESSY EATER. 328 00:19:58,533 --> 00:20:00,300 IT'S TRYING TO SUCK MATTER IN, 329 00:20:00,300 --> 00:20:03,233 BUT IT ENDS UP SUPERHEATING MATTER AND EXPELLING MATTER, 330 00:20:03,233 --> 00:20:06,367 AND SOMETIMES, IT WILL EVEN BELCH DURING ITS MEAL 331 00:20:06,367 --> 00:20:07,800 AND HAVE AN OUTBURST. 332 00:20:10,033 --> 00:20:11,433 Narrator: IN THE EARLY UNIVERSE, 333 00:20:11,433 --> 00:20:15,800 THE SUPERMASSIVE BLACK HOLE, THE BEGINNINGS OF THE MILKY WAY, 334 00:20:15,800 --> 00:20:20,167 IS SURROUNDED BY GAS AND DUST. 335 00:20:20,167 --> 00:20:25,067 THE BLACK HOLES FEAST ON THE MATTER. 336 00:20:25,067 --> 00:20:29,100 BUT NOT ALL OF IT IS DOOMED. 337 00:20:29,100 --> 00:20:32,400 WHEN IT EATS TOO MUCH TOO QUICKLY, 338 00:20:32,400 --> 00:20:34,533 IT GENERATES SO MUCH ENERGY 339 00:20:34,533 --> 00:20:37,733 THAT EVEN THE BLACK HOLE'S GRAVITY CAN'T CONTAIN IT. 340 00:20:40,333 --> 00:20:43,633 SUDDENLY, THE MILKY WAY FIRES OFF 341 00:20:43,633 --> 00:20:47,333 HIGHLY ENERGIZED ATOMS AND LIGHT FROM THE CORE... 342 00:20:53,167 --> 00:20:57,800 ...PUMPING OUT UP TO A TRILLION TIMES MORE ENERGY THAN OUR SUN. 343 00:20:59,833 --> 00:21:02,867 IF YOU WERE TO HAVE A CLOSE ENCOUNTER WITH A SUPERMASSIVE BLACK HOLE, 344 00:21:02,867 --> 00:21:05,133 YOU'RE GONNA HAVE TO GO THROUGH A VERY DANGEROUS ENVIRONMENT. 345 00:21:05,133 --> 00:21:08,967 YOU'D HAVE TO SURVIVE THE INTENSE RADIATION. 346 00:21:08,967 --> 00:21:10,800 YOU'D HAVE TO SURVIVE THE JET. 347 00:21:13,467 --> 00:21:16,833 Narrator: SO HOW DO STARS FORM AROUND SUCH VIOLENCE? 348 00:21:16,833 --> 00:21:21,267 ASTRONOMERS FIND A BLACK HOLE WHICH MIGHT HOLD THE KEY 349 00:21:21,267 --> 00:21:24,967 TO HOW THE MILKY WAY GOT ITS FIRST STARS. 350 00:21:24,967 --> 00:21:27,500 Bullock: THERE'S A REALLY EXCITING DISCOVERY 351 00:21:27,500 --> 00:21:29,233 OF A SUPERMASSIVE BLACK HOLE, 352 00:21:29,233 --> 00:21:31,900 THE KIND WE NORMALLY ONLY FIND AT THE HEARTS OF GALAXIES, 353 00:21:31,900 --> 00:21:34,900 SITTING OUT THERE BY ITSELF WITH NO GALAXY AROUND IT. 354 00:21:34,900 --> 00:21:41,067 THIS THING'S SHINING LIKE CRAZY, SO WE KNOW IT'S GOBBLING UP GAS. 355 00:21:41,067 --> 00:21:45,567 Narrator: HE0450-2958 356 00:21:45,567 --> 00:21:48,400 SITS 5 BILLION LIGHT-YEARS FROM EARTH, 357 00:21:48,400 --> 00:21:50,933 A BLACK HOLE WITH A HUGE JET. 358 00:21:52,833 --> 00:21:55,833 THIS JET IS SMASHING INTO DUST AND GAS 359 00:21:55,833 --> 00:21:58,067 AND ITS NEIGHBORING GALAXY. 360 00:21:58,067 --> 00:22:00,433 YOU'D THINK IT WOULD DESTROY THE GALAXY, 361 00:22:00,433 --> 00:22:02,933 BUT INSTEAD, IT'S HELPING TO BUILD IT. 362 00:22:02,933 --> 00:22:06,200 Bullock: IT'S NEXT TO A BIG GALAXY, 363 00:22:06,200 --> 00:22:09,967 AND THIS BIG GALAXY IS FORMING STARS LIKE CRAZY. 364 00:22:09,967 --> 00:22:12,567 SO WE THINK WHAT'S GOING ON IS, BECAUSE OF THE STUFF 365 00:22:12,567 --> 00:22:14,933 COMING OFF OF THE BLACK HOLE AS IT'S GROWING, 366 00:22:14,933 --> 00:22:17,233 THERE ARE STARS BEING TRIGGERED TO FORM 367 00:22:17,233 --> 00:22:18,733 IN THIS GALAXY NEXT TO IT. 368 00:22:22,133 --> 00:22:24,267 Narrator: THE BLACK HOLE'S COLOSSAL JET 369 00:22:24,267 --> 00:22:28,400 IS THE SPARK NEEDED TO CREATE A STAR FACTORY. 370 00:22:28,400 --> 00:22:32,067 Bullock: THE BLACK HOLE IS EMITTING RADIATION. 371 00:22:32,067 --> 00:22:35,433 AND WHEN THIS RADIATION RUNS INTO ALL THE GAS IN THE GALAXY, 372 00:22:35,433 --> 00:22:37,400 THIS CAUSES THE GAS TO CLUMP TOGETHER, 373 00:22:37,400 --> 00:22:38,600 AND NEW STARS GET MADE. 374 00:22:40,767 --> 00:22:45,300 Narrator: DIRECT EVIDENCE THAT BLACK HOLES CAN CREATE STARS. 375 00:22:45,300 --> 00:22:54,167 HE0450-2958 MIGHT BE A LOOK BACK INTO THE MILKY WAY'S PAST. 376 00:22:56,100 --> 00:22:58,767 OUR GALAXY'S SUPERMASSIVE BLACK HOLE'S 377 00:22:58,767 --> 00:23:02,667 VIOLENT FEASTING SPARKS STARS INTO LIFE. 378 00:23:02,667 --> 00:23:05,567 THESE STARS ARE DRAWN 379 00:23:05,567 --> 00:23:08,433 BY THE BLACK HOLE'S HUGE GRAVITY AND ORBIT, 380 00:23:08,433 --> 00:23:10,600 BUILDING THE GALAXY. 381 00:23:10,600 --> 00:23:11,933 Kaku: WELL, THE BLACK HOLE 382 00:23:11,933 --> 00:23:15,367 COULD ACTUALLY STIMULATE STAR FORMATION. 383 00:23:15,367 --> 00:23:18,433 SO SOME PEOPLE BELIEVE THAT THE VERY FACT THAT WE HAVE GALAXIES 384 00:23:18,433 --> 00:23:19,700 IS DUE TO THE FACT 385 00:23:19,700 --> 00:23:22,133 THAT WE HAVE A RAGING BLACK HOLE AT THE CENTER 386 00:23:22,133 --> 00:23:25,067 WHICH HELPS TO INITIATE STAR FORMATION. 387 00:23:28,133 --> 00:23:30,633 IT'S POSSIBLE THAT THE BLACK HOLE 388 00:23:30,633 --> 00:23:34,800 COULD HAVE CREATED MANY OF THE STARS WE SEE IN OUR SKY TODAY, 389 00:23:34,800 --> 00:23:39,400 INCLUDING THE ONE STAR WE CAN'T LIVE WITHOUT, 390 00:23:39,400 --> 00:23:42,167 OUR SUN. 391 00:23:42,167 --> 00:23:44,333 Krauss: IT'S KIND OF AMAZING 392 00:23:44,333 --> 00:23:47,200 THAT BLACK HOLES EXISTED AS THEORETICAL CONSTRUCTS 393 00:23:47,200 --> 00:23:48,867 THAT MANY OF THE PHYSICISTS WHO WERE INVOLVED 394 00:23:48,867 --> 00:23:50,633 IN DEVELOPING THOSE CONSTRUCTS DIDN'T BELIEVE IN. 395 00:23:50,633 --> 00:23:53,167 NOW, WE UNDERSTAND THAT EVEN PERHAPS 396 00:23:53,167 --> 00:23:55,733 OUR VERY EXISTENCE DEPENDS UPON THEM. 397 00:23:55,733 --> 00:23:59,267 THEY'VE GONE FROM OBJECTS IN OUR IMAGINATION 398 00:23:59,267 --> 00:24:02,100 TO OBJECTS ON WHICH OUR LIFE DEPENDS. 399 00:24:05,367 --> 00:24:08,067 Plait: EVEN THOUGH THIS BLACK HOLE IN THE CENTER 400 00:24:08,067 --> 00:24:09,567 IS TERRIFYING TO CONCEIVE OF, 401 00:24:09,567 --> 00:24:12,167 IN FACT, OUR GALAXY DEPENDS ON IT. 402 00:24:12,167 --> 00:24:14,067 AND OUR OWN PLANET AND STAR 403 00:24:14,067 --> 00:24:17,067 MAY HAVE FORMED BECAUSE OF THIS SYSTEM. 404 00:24:23,667 --> 00:24:25,700 Narrator: 13 BILLION YEARS AGO, 405 00:24:25,700 --> 00:24:30,900 THE FIRST STARS OF THE MILKY WAY SPARK INTO LIFE. 406 00:24:30,900 --> 00:24:35,400 THE GALAXY STARTS TO TAKE SHAPE. 407 00:24:35,400 --> 00:24:40,600 THE MILKY WAY IS NOW BIG ENOUGH TO THROW ITS WEIGHT AROUND. 408 00:24:42,733 --> 00:24:47,100 AND IN THE EARLY UNIVERSE, THE MILKY WAY IS NOT ALONE. 409 00:24:47,100 --> 00:24:51,833 ITS COSMIC NEIGHBORS BECOME ITS PREY. 410 00:24:51,833 --> 00:24:55,767 THE MILKY WAY BECOMES A CANNIBAL. 411 00:25:05,867 --> 00:25:08,567 Narrator: THE YOUNG MILKY WAY IS GROWING. 412 00:25:08,567 --> 00:25:12,133 IT ALREADY CONTAINS MILLIONS OF STARS. 413 00:25:12,133 --> 00:25:17,700 NOW, IT'S BIG ENOUGH TO ENTER ITS NEXT STAGE OF EVOLUTION. 414 00:25:17,700 --> 00:25:21,067 IT'S TIME TO GET VIOLENT. 415 00:25:21,067 --> 00:25:26,300 OUR GALAXY TURNS ON ITS COSMIC SIBLINGS. 416 00:25:26,300 --> 00:25:29,433 Kaku: GALAXIES ARE GORGEOUS, 417 00:25:29,433 --> 00:25:30,833 HUGE PINWHEELS 418 00:25:30,833 --> 00:25:33,600 SPIRALING ELEGANTLY THROUGHOUT THE UNIVERSE. 419 00:25:33,600 --> 00:25:35,833 BUT THERE'S A DARK SIDE TO THESE GALAXIES. 420 00:25:35,833 --> 00:25:39,400 THE PROCESS OF BUILDING UP GALAXIES IS ONE OF CANNIBALISM. 421 00:25:39,400 --> 00:25:42,700 THE GALAXIES DON'T FORM EN MASSE AS LARGE OBJECTS. 422 00:25:42,700 --> 00:25:45,067 WHAT THEY DO, LIKE MANY THINGS, 423 00:25:45,067 --> 00:25:48,433 IS FORM BY EATING SMALLER OBJECTS. 424 00:25:51,067 --> 00:25:53,567 Narrator: IF WE COULD VIEW THE INFANT UNIVERSE, 425 00:25:53,567 --> 00:25:56,567 WE WOULD SEE A BATTLE RAGING. 426 00:25:56,567 --> 00:26:00,067 DWARF GALAXIES COLLIDE AND MERGE. 427 00:26:00,067 --> 00:26:04,767 AND IN THIS ARENA, SIZE MATTERS. 428 00:26:04,767 --> 00:26:07,233 [ CHEERS AND APPLAUSE ] 429 00:26:09,067 --> 00:26:12,667 IT'S A COSMIC ROLLER-DERBY MATCH. 430 00:26:15,067 --> 00:26:17,733 THE PLAYERS REPRESENT DWARF GALAXIES 431 00:26:17,733 --> 00:26:20,500 WHICH POPULATE THE EARLY UNIVERSE. 432 00:26:20,500 --> 00:26:23,367 Bullock: IF YOU LOOK AT A ROLLER-DERBY MATCH, 433 00:26:23,367 --> 00:26:25,867 YOU MIGHT GET A BETTER IDEA ABOUT WHAT GALAXY FORMATION'S LIKE. 434 00:26:30,400 --> 00:26:33,733 YOU'VE GOT PEOPLE SKATING AROUND THE MIDDLE OF A RINK. 435 00:26:38,700 --> 00:26:40,600 THERE'S PEOPLE SLAMMING ALL OVER THE PLACE. 436 00:26:40,600 --> 00:26:45,067 IT'S A VERY VIOLENT PROCESS, REALLY CHAOTIC. 437 00:26:45,067 --> 00:26:48,200 AND IT'S EXACTLY THE SAME WAY AROUND THE GALAXY. 438 00:26:50,133 --> 00:26:53,633 [ CHEERING ] 439 00:26:53,633 --> 00:26:55,400 IN A GALAXY, YOU'VE GOT THIS MIDDLE 440 00:26:55,400 --> 00:26:56,900 THAT'S ATTRACTING EVERYTHING, 441 00:26:56,900 --> 00:26:59,133 AND STUFF IS SWIMMING AROUND IT. 442 00:26:59,133 --> 00:27:02,967 Narrator: DWARF GALAXIES SMASH INTO ONE ANOTHER. 443 00:27:02,967 --> 00:27:06,067 THE LARGER ALWAYS GET THE UPPER HAND. 444 00:27:06,067 --> 00:27:08,367 Bullock: YOU'VE GOT ALL THIS STUFF SLAMMING TOGETHER. 445 00:27:08,367 --> 00:27:10,367 STARS ARE GETTING THROWN ALL OVER THE PLACE. 446 00:27:10,367 --> 00:27:14,133 THEY STRIP MASS FROM EACH OTHER. THEY COLLIDE. 447 00:27:14,133 --> 00:27:16,367 AND IF THERE ARE ANY SMALLER OBJECTS IN-BETWEEN, 448 00:27:16,367 --> 00:27:18,100 THEY GET EATEN UP. 449 00:27:18,100 --> 00:27:22,833 Narrator: IT'S BILLIONS OF YEARS OF DESTRUCTIVE MAYHEM. 450 00:27:22,833 --> 00:27:25,500 IT'S JUST THIS CRAZY, VIOLENT DANCE 451 00:27:25,500 --> 00:27:27,167 THAT JUST GOES ON OVER AND OVER AGAIN. 452 00:27:30,767 --> 00:27:33,067 Narrator: IN THE CHAOS OF COLLISIONS, 453 00:27:33,067 --> 00:27:35,700 THE MILKY WAY GROWS BIGGER. 454 00:27:39,733 --> 00:27:45,267 TODAY, OUR GALAXY DOMINATES OUR PART OF THE UNIVERSE. 455 00:27:45,267 --> 00:27:49,733 AND EVEN NOW, IT'S STILL DEVOURING OTHER GALAXIES. 456 00:27:51,733 --> 00:27:54,067 THERE IS A GALAXY CALLED SAGITTARIUS 457 00:27:54,067 --> 00:27:57,500 WHICH HAS LEFT A HUGE TRAIL OF STARS AROUND THE MILKY WAY 458 00:27:57,500 --> 00:28:00,700 AND IS ESSENTIALLY IN THE PROCESS OF BEING DEVOURED. 459 00:28:00,700 --> 00:28:04,400 Bullock: THERE'S A GIANT STREAM OF STARS COMING OFF OF IT. 460 00:28:04,400 --> 00:28:06,300 SO IT'S TOTALLY JUST BEING RIPPED APART 461 00:28:06,300 --> 00:28:07,433 BY THE MILKY WAY ITSELF. 462 00:28:07,433 --> 00:28:09,867 Narrator: BUT IN THIS BATTLE, 463 00:28:09,867 --> 00:28:13,533 THE MILKY WAY DOESN'T GO UNSCATHED. 464 00:28:13,533 --> 00:28:16,333 Bullock: THIS COLLISION COULD'VE TRIGGERED THE FORMATION 465 00:28:16,333 --> 00:28:18,467 OF THE SPIRAL ARMS OF THE MILKY WAY ITSELF. 466 00:28:18,467 --> 00:28:21,067 SO THE REASON WHY THE MILKY WAY IS A SPIRAL GALAXY 467 00:28:21,067 --> 00:28:24,833 MIGHT BE BECAUSE IT'S EATING UP SAGITTARIUS. 468 00:28:24,833 --> 00:28:30,267 Narrator: VIOLENCE DOESN'T JUST BUILD OUR GALAXY. 469 00:28:30,267 --> 00:28:32,100 IT SCULPTS IT... 470 00:28:34,500 --> 00:28:37,233 ...SMASHING THE MILKY WAY INTO SHAPE 471 00:28:37,233 --> 00:28:41,600 AND REARRANGING THE POSITIONS OF THE STARS, 472 00:28:41,600 --> 00:28:44,367 PERHAPS EVEN OUR SUN. 473 00:28:44,367 --> 00:28:48,200 IT'S POSSIBLE THAT THE SUN WAS ACTUALLY BORN 474 00:28:48,200 --> 00:28:50,267 MUCH CLOSER TO THE MIDDLE OF THE GALAXY, 475 00:28:50,267 --> 00:28:52,200 AND IT'S MIGRATED OUT HERE TO THE SUBURBS 476 00:28:52,200 --> 00:28:54,467 OVER THE COURSE OF THE LAST COUPLE BILLION YEARS. 477 00:28:54,467 --> 00:28:57,300 AND IT'S POSSIBLE THAT WHEN SAGITTARIUS HIT THE DISK, 478 00:28:57,300 --> 00:28:59,200 IT CREATED SOME SPIRAL ARMS 479 00:28:59,200 --> 00:29:02,267 THAT THEN ALLOWED THE SUN TO MIGRATE OUT. 480 00:29:04,500 --> 00:29:06,600 Narrator: THE SUN AND OUR SOLAR SYSTEM 481 00:29:06,600 --> 00:29:11,300 ARE NOW ABOUT 26,000 LIGHT-YEARS FROM THE GALAXY'S CENTER. 482 00:29:11,300 --> 00:29:15,067 FOR LIFE ON EARTH, THAT'S GOOD NEWS. 483 00:29:15,067 --> 00:29:17,633 Thaller: IF YOU'RE TOO CLOSE TO THE BIG BLACK HOLE IN THE CENTER, 484 00:29:17,633 --> 00:29:19,967 THERE'S A LOT GOING ON THAT CAN ACTUALLY HURT LIFE. 485 00:29:19,967 --> 00:29:21,867 THERE'S HIGH-ENERGY RADIATION. 486 00:29:21,867 --> 00:29:25,333 THERE ARE BURSTS OF STAR FORMATION, SUPERNOVA EXPLOSIONS. 487 00:29:25,333 --> 00:29:28,700 WE'RE IN A QUIETER, KIND OF OUTLYING SUBURB OF THE GALAXY. 488 00:29:28,700 --> 00:29:31,367 AND THINGS THERE ARE MUCH MORE CONDUCIVE TO LIFE. 489 00:29:31,367 --> 00:29:34,667 Narrator: OUR GALAXY'S CANNIBALISM 490 00:29:34,667 --> 00:29:38,067 PROVES ESSENTIAL FOR LIFE ON EARTH. 491 00:29:38,067 --> 00:29:41,200 THROUGH VIOLENCE, WE'RE ABLE TO LIVE, 492 00:29:41,200 --> 00:29:44,867 AND OUR GALAXY CONTINUES TO GROW. 493 00:29:47,433 --> 00:29:48,933 BUT CAN ANYTHING STOP 494 00:29:48,933 --> 00:29:52,433 THE JUGGERNAUT OF OUR CANNIBAL GALAXY? 495 00:29:54,600 --> 00:29:56,433 LOOKING OUT AT THE MILKY WAY, 496 00:29:56,433 --> 00:30:00,067 ASTRONOMERS FIND HARDLY ANY NEW STARS. 497 00:30:00,067 --> 00:30:04,967 TURNS OUT, SOMETHING IS SHUTTING OUR GALAXY'S GROWTH DOWN, 498 00:30:04,967 --> 00:30:08,333 THE BIGGEST FLAMETHROWER IN THE UNIVERSE. 499 00:30:18,833 --> 00:30:21,600 Narrator: THE MILKY WAY STARTED SMALL. 500 00:30:21,600 --> 00:30:25,700 OVER BILLIONS OF YEARS, IT HAS GROWN HUGE, 501 00:30:25,700 --> 00:30:29,733 SPAWNING OVER 200 BILLION STARS AND COUNTING. 502 00:30:29,733 --> 00:30:33,267 BUT THE COUNT IS SLOWING. 503 00:30:33,267 --> 00:30:34,500 SO, IN THE MILKY WAY RIGHT NOW, 504 00:30:34,500 --> 00:30:36,033 THERE ARE STARS THAT ARE BEING BORN. 505 00:30:36,033 --> 00:30:37,533 AND THERE'S ABOUT ONE STAR PER YEAR 506 00:30:37,533 --> 00:30:40,000 SOMEWHERE IN OUR GIANT GALAXY THAT'S BEING BORN. 507 00:30:40,000 --> 00:30:42,100 STAR FORMATION'S NOT DONE IN THE MILKY WAY, 508 00:30:42,100 --> 00:30:43,233 BUT IT'S SETTLED DOWN. 509 00:30:45,267 --> 00:30:47,233 Narrator: IN ITS PAST, THE MILKY WAY 510 00:30:47,233 --> 00:30:49,867 WAS BURSTING WITH STAR FORMATION. 511 00:30:49,867 --> 00:30:51,733 SO WHAT'S CHANGED? 512 00:30:53,633 --> 00:30:56,500 Bullock: SO, ONE OF THE BIG QUESTIONS IN GALAXY FORMATION TODAY IS, 513 00:30:56,500 --> 00:30:58,433 WHY ISN'T MORE GAS TURNING INTO STARS? 514 00:30:58,433 --> 00:31:00,267 WELL, ONE CLUE IS THAT BLACK HOLES 515 00:31:00,267 --> 00:31:02,300 ACTUALLY MIGHT BE LIMITING THIS PROCESS. 516 00:31:05,500 --> 00:31:07,067 Narrator: IN THE EARLY UNIVERSE, 517 00:31:07,067 --> 00:31:11,300 OUR BLACK HOLE MAY HAVE SPARKED STARS INTO LIFE. 518 00:31:11,300 --> 00:31:15,400 NOW, IT MIGHT BE STOPPING STARS FROM FORMING. 519 00:31:15,400 --> 00:31:18,467 TO FIND OUT WHY, WE NEED TO LOOK 520 00:31:18,467 --> 00:31:22,300 AT THE MILKY WAY'S SUPERMASSIVE BLACK HOLE IN DETAIL. 521 00:31:25,467 --> 00:31:28,633 AND FOR THE FIRST TIME, WE CAN, 522 00:31:28,633 --> 00:31:32,933 THANKS TO ONE OF NASA'S NEWEST SPACE TELESCOPES, NuSTAR. 523 00:31:32,933 --> 00:31:37,267 FIONA HARRISON RUNS THE NuSTAR MISSION. 524 00:31:37,267 --> 00:31:39,333 ITS FIRST TARGET -- 525 00:31:39,333 --> 00:31:42,200 THE BLACK HOLE AT THE CENTER OF OUR GALAXY. 526 00:31:43,667 --> 00:31:46,767 Harrison: NuSTAR CAN SEE THE VERY HIGHEST-ENERGY X-RAYS 527 00:31:46,767 --> 00:31:49,133 THAT CAN PENETRATE THROUGH DUST AND GAS. 528 00:31:49,133 --> 00:31:52,633 IT ENABLES US TO HAVE THIS VIEW OF THIS BLACK HOLE. 529 00:31:54,533 --> 00:31:56,567 Narrator: NuSTAR'S X-RAY VISION 530 00:31:56,567 --> 00:32:00,367 SEES ONLY THE MOST VIOLENT EVENTS. 531 00:32:00,367 --> 00:32:07,067 BLACK HOLE TANTRUMS ARE RARE, BUT NuSTAR GOT LUCKY. 532 00:32:07,067 --> 00:32:08,833 Harrison: WE LOOKED. 533 00:32:08,833 --> 00:32:10,700 AND ABOUT SIX HOURS AFTER WE LOOKED, 534 00:32:10,700 --> 00:32:15,800 WE SAW THE BLACK HOLE GET A HUNDRED TIMES BRIGHTER. 535 00:32:15,800 --> 00:32:18,933 HOW LONG DID THAT LAST? ONLY A FEW HOURS. 536 00:32:18,933 --> 00:32:20,933 THEN IT FADED AWAY BACK INTO OBLIVION. 537 00:32:20,933 --> 00:32:25,667 BUT THIS EVENT WAS WHAT WE WERE LOOKING FOR. 538 00:32:25,667 --> 00:32:28,367 WE WERE ALL JUST AMAZED. 539 00:32:28,367 --> 00:32:30,267 THERE WERE CHEERS IN THE ROOM. 540 00:32:30,267 --> 00:32:32,600 IT WAS JUST ONE OF THE MOST EXCITING MOMENTS, 541 00:32:32,600 --> 00:32:34,600 AND SO EARLY ON IN THE MISSION, TOO. 542 00:32:34,600 --> 00:32:37,533 Narrator: IT'S DIRECT EVIDENCE 543 00:32:37,533 --> 00:32:40,067 OUR BLACK HOLE IS STILL ACTIVE 544 00:32:40,067 --> 00:32:43,433 AND STILL HAS THE MUSCLE TO CONTROL THE GALAXY. 545 00:32:47,967 --> 00:32:50,433 THE BLACK HOLE'S POWER IS REVEALED 546 00:32:50,433 --> 00:32:56,500 WHEN IT LIGHTS UP A DISK OF GAS AND DUST WHICH SPINS AROUND IT. 547 00:32:56,500 --> 00:32:59,700 AS THIS MATERIAL IS SWIRLING AROUND THE BLACK HOLE IN A DISK, 548 00:32:59,700 --> 00:33:01,233 IT RUBS AGAINST EACH OTHER. 549 00:33:01,233 --> 00:33:03,900 AND THERE'S ALSO MAGNETIC FIELDS AND OTHER FORCES. 550 00:33:03,900 --> 00:33:07,800 ALL OF THIS HEATS THAT DISK TO MUCH HOTTER, EVEN, THAN THE SUN. 551 00:33:10,933 --> 00:33:13,933 Narrator: NuSTAR DETECTS THAT GAS AROUND THE BLACK HOLE 552 00:33:13,933 --> 00:33:17,967 IS HEATING UP TO 180 MILLION DEGREES FAHRENHEIT. 553 00:33:17,967 --> 00:33:22,167 THAT'S 18,000 TIMES HOTTER THAN THE SURFACE OF THE SUN. 554 00:33:24,200 --> 00:33:28,700 THIS SUPERHEATED GAS IS BAD NEWS FOR STAR FORMATION. 555 00:33:28,700 --> 00:33:33,267 THE GAS HAS TO GET COLD IN ORDER FOR IT TO EVENTUALLY FORM STARS. 556 00:33:33,267 --> 00:33:35,567 AND THAT'S BECAUSE THE GAS HAS TO GET VERY, VERY DENSE 557 00:33:35,567 --> 00:33:37,567 SO THAT, EVENTUALLY, THE GAS CAN COLLAPSE 558 00:33:37,567 --> 00:33:40,300 INTO SOMETHING THAT'S GONNA HAVE NUCLEAR FUSION IN ITS CORE. 559 00:33:40,300 --> 00:33:42,567 SO IN REGIONS AROUND BLACK HOLES, 560 00:33:42,567 --> 00:33:44,067 BECAUSE THEY'RE SO HOT, 561 00:33:44,067 --> 00:33:45,667 THEY HEAT UP THE GAS AROUND THEM. 562 00:33:45,667 --> 00:33:47,367 AND THAT TOTALLY LIMITS THE ABILITY 563 00:33:47,367 --> 00:33:48,800 FOR THAT GAS TO TURN INTO STARS. 564 00:33:51,400 --> 00:33:54,167 MASSIVE AMOUNTS OF ENERGY ARE EMITTED. 565 00:33:54,167 --> 00:33:57,067 AND THAT ACTUALLY CAN NOT ONLY DESTROY STARS, 566 00:33:57,067 --> 00:34:00,867 IT CAN BLOW THE GAS AWAY THAT WOULD LATER ON FORM STARS. 567 00:34:03,567 --> 00:34:06,367 Narrator: STAR BIRTH SHUTS DOWN. 568 00:34:09,333 --> 00:34:10,833 OVER OUR GALAXY'S LIFE, 569 00:34:10,833 --> 00:34:15,067 OUR SUPERMASSIVE BLACK HOLE DRAGS GAS AND DUST TOWARDS IT, 570 00:34:15,067 --> 00:34:18,167 THE INGREDIENTS NEEDED FOR STAR FORMATION. 571 00:34:18,167 --> 00:34:20,167 IN ITS INFANCY, 572 00:34:20,167 --> 00:34:23,300 ITS POWER SLAMS THESE GAS CLOUDS TOGETHER, 573 00:34:23,300 --> 00:34:26,067 SPARKING STARS INTO LIFE. 574 00:34:26,067 --> 00:34:30,433 NOW, IT BLOWS THEM APART WITH ITS EXTREME HEAT, 575 00:34:30,433 --> 00:34:34,533 REGULATING THE POPULATION OF STARS IN THE GALAXY. 576 00:34:34,533 --> 00:34:38,100 THE BLACK HOLE IN THE CENTER ACTS A LITTLE BIT LIKE A VALVE, 577 00:34:38,100 --> 00:34:40,967 CONTROLLING HOW STARS FORM IN THE GALAXY ITSELF. 578 00:34:40,967 --> 00:34:44,933 Krauss: THERE IS A REMARKABLE SYMBIOTIC RELATIONSHIP 579 00:34:44,933 --> 00:34:46,600 BETWEEN BLACK HOLES AND GALAXIES. 580 00:34:46,600 --> 00:34:50,567 BLACK HOLES ACT LIKE COSMIC REGULATORS, 581 00:34:50,567 --> 00:34:53,167 INCREASING, AT CERTAIN TIMES, STAR FORMATION 582 00:34:53,167 --> 00:34:56,100 AND GOVERNING THE RATE AT WHICH GALAXIES EVOLVE. 583 00:34:56,100 --> 00:34:59,467 Narrator: WE'RE NOT SURE WHY OUR BLACK HOLE 584 00:34:59,467 --> 00:35:04,200 STOPS SOME STAR FORMATION AND SPARKS OTHERS. 585 00:35:04,200 --> 00:35:06,333 ALL WE DO KNOW 586 00:35:06,333 --> 00:35:10,167 IS THAT THIS REGULATION MIGHT BE ESSENTIAL FOR US. 587 00:35:10,167 --> 00:35:12,200 WHEN IT MADE STARS, 588 00:35:12,200 --> 00:35:16,133 THE BLACK HOLE MIGHT HAVE ALSO HELPED CREATE OUR SUN. 589 00:35:16,133 --> 00:35:19,933 NOW, IT LIMITS STAR FORMATION, 590 00:35:19,933 --> 00:35:24,267 WHICH COULD BRING LETHAL RADIATION NEAR PLANET EARTH. 591 00:35:24,267 --> 00:35:26,533 Bullock: IF WE WERE LIVING IN AN AREA WHERE THERE WERE 592 00:35:26,533 --> 00:35:28,500 LOTS OF YOUNG STARS AND SUPERNOVAE BLOWING UP, 593 00:35:28,500 --> 00:35:31,133 THAT WOULD NOT BE SO GOOD FOR LIFE ON EARTH. 594 00:35:31,133 --> 00:35:36,433 Narrator: NOW THE CONDITIONS FOR LIFE ARE PERFECT. 595 00:35:36,433 --> 00:35:42,800 LOOKING UP AT OUR NIGHT SKY, IT LOOKS UNCHANGING, ETERNAL. 596 00:35:45,067 --> 00:35:48,400 BUT IN THE UNIVERSE, NOTHING LASTS FOREVER. 597 00:35:50,433 --> 00:35:54,733 OUR GALAXY IS GEARING UP FOR ITS NEXT BIG CHANGE. 598 00:35:54,733 --> 00:35:59,467 SO WHAT DOES THE FUTURE HOLD? 599 00:35:59,467 --> 00:36:02,567 THE ANSWER IS THAT WE WON'T BE A SPIRAL GALAXY FOR MUCH LONGER. 600 00:36:02,567 --> 00:36:04,867 OUR LIFETIME AS A SPIRAL GALAXY 601 00:36:04,867 --> 00:36:08,167 IS ABOUT TWO-THIRDS OF THE WAY INTO ITS FINAL DEATH THROES. 602 00:36:10,267 --> 00:36:12,967 Narrator: THE MILKY WAY HAS A GIANT SISTER OUT THERE, 603 00:36:12,967 --> 00:36:15,800 TOO CLOSE FOR COMFORT. 604 00:36:15,800 --> 00:36:20,267 THEIR SIBLING RIVALRY WILL SET THE NIGHT ON FIRE 605 00:36:22,767 --> 00:36:26,367 AND PIT TWO OF THE BIGGEST HEAVYWEIGHTS IN THE COSMOS 606 00:36:26,367 --> 00:36:29,067 IN A FIGHT TO THE DEATH. 607 00:36:38,367 --> 00:36:40,433 Narrator: AROUND 13 BILLION YEARS AGO, 608 00:36:40,433 --> 00:36:45,200 THE MILKY WAY FORMS AROUND A SUPERMASSIVE BLACK HOLE. 609 00:36:45,200 --> 00:36:49,100 IT ADDS HUNDREDS OF BILLIONS OF STARS, 610 00:36:49,100 --> 00:36:56,067 SETTLES INTO A FLAT DISK AND IS SCULPTED INTO A SPIRAL. 611 00:36:56,067 --> 00:36:59,733 OUR GALAXY HAS CONSTANTLY EVOLVED. 612 00:36:59,733 --> 00:37:03,100 ITS FUTURE IS NO DIFFERENT. 613 00:37:03,100 --> 00:37:07,367 AND IT'S GOING TO GET VIOLENT. 614 00:37:07,367 --> 00:37:09,233 GO OUT TONIGHT AND LOOK AT THE NIGHT SKY 615 00:37:09,233 --> 00:37:10,433 WITH A PAIR OF BINOCULARS, 616 00:37:10,433 --> 00:37:14,167 AND YOU CAN SEE THE ANDROMEDA GALAXY. 617 00:37:14,167 --> 00:37:17,467 THAT IS OUR FUTURE. 618 00:37:17,467 --> 00:37:20,700 PERHAPS 4 OR 5 BILLION YEARS FROM NOW, 619 00:37:20,700 --> 00:37:24,467 WE WILL BE ON A COLLISION COURSE WITH OUR NEXT-DOOR NEIGHBOR. 620 00:37:24,467 --> 00:37:27,600 AND IT COULD BE LIKE A HOSTILE TAKEOVER. 621 00:37:29,700 --> 00:37:33,067 Narrator: ANDROMEDA IS HEADING STRAIGHT FOR US. 622 00:37:33,067 --> 00:37:36,467 COLLISIONS ARE, OF COURSE, NOTHING NEW. 623 00:37:36,467 --> 00:37:38,633 IN ITS INFANCY, 624 00:37:38,633 --> 00:37:43,400 OUR GALAXY GREW BY COLLIDING AND EATING OTHER GALAXIES. 625 00:37:43,400 --> 00:37:46,833 BUT THIS TIME, IT'S DIFFERENT. 626 00:37:46,833 --> 00:37:51,667 THE ORIGINAL SCHOOLYARD BULLY IS GOING TO MEET ITS MATCH. 627 00:37:54,133 --> 00:37:56,300 THE MILKY WAY HAS ALWAYS BEEN THE BIGGEST THING AROUND. 628 00:37:56,300 --> 00:37:58,467 SO ANY LITTLE DWARF GALAXY THAT'S GOTTEN NEAR 629 00:37:58,467 --> 00:37:59,600 HAS GOTTEN TORN APART, 630 00:37:59,600 --> 00:38:01,767 BUT THE MILKY WAY JUST KEEPS RIGHT ON GOING. 631 00:38:01,767 --> 00:38:04,100 NOW, THERE'S ANOTHER REALLY BIG GALAXY 632 00:38:04,100 --> 00:38:06,133 THAT'S ACTUALLY HEADED RIGHT FOR US RIGHT NOW. 633 00:38:06,133 --> 00:38:08,433 THAT'S ANDROMEDA. IT'S ANOTHER DISK. 634 00:38:08,433 --> 00:38:10,633 AND WHEN THESE TWO BIG DISKS COME TOGETHER, 635 00:38:10,633 --> 00:38:11,967 THERE'S NOT GONNA BE A DISK LEFT. 636 00:38:11,967 --> 00:38:14,500 NEITHER OF THOSE DISKS IS GONNA WIN. 637 00:38:14,500 --> 00:38:16,967 Narrator: AS THE COLLISION NEARS, 638 00:38:16,967 --> 00:38:20,100 OUR NIGHT SKY WILL CHANGE COMPLETELY. 639 00:38:20,100 --> 00:38:23,233 Bullock: TODAY, IF YOU LOOK OUT WHEN IT'S REALLY DARK, 640 00:38:23,233 --> 00:38:25,933 YOU SEE THE BIG BAND OF THE MILKY WAY. 641 00:38:25,933 --> 00:38:27,533 IT'S A BEAUTIFUL THING. 642 00:38:27,533 --> 00:38:28,800 A FEW BILLION YEARS FROM NOW, 643 00:38:28,800 --> 00:38:31,067 WHAT YOU WOULD SEE IS NOT JUST ONE BAND OF STARS, 644 00:38:31,067 --> 00:38:34,500 BUT ANOTHER BAND OF STARS THAT CRISSCROSSES LIKE THIS. 645 00:38:34,500 --> 00:38:37,300 Narrator: AS IT NEARS, 646 00:38:37,300 --> 00:38:41,700 ANDROMEDA GROWS LARGER AND LARGER IN OUR SKY. 647 00:38:41,700 --> 00:38:46,100 FINALLY, THE GALAXIES SMASH INTO ONE ANOTHER. 648 00:38:46,100 --> 00:38:51,133 STARS ARE TORN FROM THEIR ORBITS. 649 00:38:51,133 --> 00:38:53,067 Plait: THE STARS DON'T ACTUALLY COLLIDE. 650 00:38:53,067 --> 00:38:54,367 STARS ARE EXTREMELY SMALL 651 00:38:54,367 --> 00:38:56,467 COMPARED TO THE SPACE IN-BETWEEN THEM. 652 00:38:56,467 --> 00:38:58,467 BUT THAT'S NOT TRUE FOR GAS CLOUDS. 653 00:38:58,467 --> 00:38:59,900 GAS CLOUDS ARE VERY LARGE. 654 00:38:59,900 --> 00:39:01,700 THEY CAN ACTUALLY SLAM INTO EACH OTHER. 655 00:39:01,700 --> 00:39:04,433 WHEN THEY COLLIDE, THAT CREATES NEW STAR FORMATION. 656 00:39:04,433 --> 00:39:09,700 THIS GAS AND DUST IS GONNA GET SET ON FIRE. 657 00:39:09,700 --> 00:39:11,467 THERE WILL BE A CRAZY THING GOING ON, 658 00:39:11,467 --> 00:39:13,767 AND MAYBE EVEN BEGIN TO LOOK LIKE FIREWORKS IN THE SKY 659 00:39:13,767 --> 00:39:14,733 AS STARS ARE BORN. 660 00:39:14,733 --> 00:39:17,800 HUGE GAS CLOUDS BLAZING OUT LIGHT 661 00:39:17,800 --> 00:39:19,700 FROM THE MASS OF STARS FORMING IN THEM. 662 00:39:19,700 --> 00:39:20,900 IT WOULD BE MAGNIFICENT. 663 00:39:25,500 --> 00:39:28,400 Narrator: THIS IS OUR SWAN SONG. 664 00:39:30,867 --> 00:39:35,833 THIS BURST OF STAR FORMATION MARKS THE END FOR OUR GALAXY. 665 00:39:40,133 --> 00:39:45,267 THE MILKY WAY AND ANDROMEDA RIP EACH OTHER TO SHREDS. 666 00:39:45,267 --> 00:39:48,933 Mainzer: WHEN THESE TWO BEAUTIFUL STRUCTURED SPIRALS 667 00:39:48,933 --> 00:39:50,267 SMACK INTO EACH OTHER, 668 00:39:50,267 --> 00:39:55,100 THAT REALLY ORDERLY SHAPE IS GOING TO BE DESTROYED. 669 00:39:55,100 --> 00:39:57,633 AND WHAT'S PROBABLY GONNA BE LEFT IS SORT 670 00:39:57,633 --> 00:40:00,833 OF A BIG BLOB OF STARS THAT'S CALLED AN ELLIPTICAL GALAXY. 671 00:40:00,833 --> 00:40:03,100 THOSE TWO GALAXIES ARE GONNA TURN INTO A BALL OF STARS. 672 00:40:03,100 --> 00:40:05,767 YOU WON'T SEE ANY BANDS AT ALL. 673 00:40:05,767 --> 00:40:09,200 IT'LL JUST BE STARS SPREAD ACROSS THE SKY. 674 00:40:11,333 --> 00:40:14,733 Narrator: THE MILKY WAY AND ANDROMEDA ARE GONE. 675 00:40:14,733 --> 00:40:20,733 IN THEIR PLACE, A NEW GALAXY, MILKOMEDA. 676 00:40:23,733 --> 00:40:26,300 BUT IT'S NOT OVER. 677 00:40:26,300 --> 00:40:31,733 THEIR TWO SUPERMASSIVE BLACK HOLES HURTLE TOWARDS EACH OTHER. 678 00:40:31,733 --> 00:40:35,633 Bullock: THOSE BLACK HOLES ARE GONNA BE HUNTING FOR EACH OTHER. 679 00:40:35,633 --> 00:40:37,467 SO YOU'VE GOT TWO GIANT BLACK HOLES, 680 00:40:37,467 --> 00:40:39,867 BOTH MORE THAN A MILLION TIMES THE MASS OF THE SUN, 681 00:40:39,867 --> 00:40:41,367 SPIRALING IN TOWARDS EACH OTHER. 682 00:40:41,367 --> 00:40:42,567 AS THIS IS HAPPENING, 683 00:40:42,567 --> 00:40:44,733 BOTH OF THEM WILL PROBABLY START GOBBLING UP GAS 684 00:40:44,733 --> 00:40:46,167 THAT HAPPENS TO BE AROUND THEM. 685 00:40:46,167 --> 00:40:48,300 THEY'RE BOTH TRYING TO EAT ALL THE GAS THAT'S AROUND THEM, 686 00:40:48,300 --> 00:40:50,533 AND THEY'RE GONNA GET BRIGHT, SO IT'S GONNA BE A CRAZY EVENT. 687 00:40:50,533 --> 00:40:52,600 IT WILL BE FANTASTIC. 688 00:40:52,600 --> 00:40:56,933 TWO FIREBALLS ROTATING AROUND EACH OTHER 689 00:40:56,933 --> 00:40:59,767 UNTIL THE BLACK HOLES AT THE CENTER OF THEM 690 00:40:59,767 --> 00:41:02,933 FINALLY COALESCE. 691 00:41:02,933 --> 00:41:04,833 Narrator: THE BLACK HOLES MERGE, 692 00:41:04,833 --> 00:41:08,300 FORMING AN EVEN LARGER SUPERMASSIVE BLACK HOLE, 693 00:41:08,300 --> 00:41:13,533 A NEW KING TO RULE OVER A NEW GALAXY. 694 00:41:16,600 --> 00:41:19,567 BUT THIS NEW GALAXY IS ALREADY DYING. 695 00:41:19,567 --> 00:41:23,400 OVER BILLIONS OF YEARS, THE STARS SLOWLY DIE OUT. 696 00:41:23,400 --> 00:41:27,667 THERE'S NO FUEL LEFT TO CREATE NEW STARS AND REPLACE THEM. 697 00:41:27,667 --> 00:41:30,967 Plait: WHAT YOU'RE LEFT WITH IS BASICALLY A DARK GALAXY. 698 00:41:30,967 --> 00:41:33,967 IT'S NOT GENERATING ANY ENERGY, ANY HEAT, ANY LIGHT. 699 00:41:33,967 --> 00:41:36,067 IT'S JUST BLACK. 700 00:41:36,067 --> 00:41:39,367 Narrator: ONE HUNDRED TRILLION YEARS 701 00:41:39,367 --> 00:41:43,600 AFTER IT WAS FORMED IN THE DARKNESS OF THE EARLY UNIVERSE, 702 00:41:43,600 --> 00:41:47,500 THE VORACIOUS BLACK HOLE RETURNS TO DARKNESS. 703 00:41:47,500 --> 00:41:51,800 HERE, IT'S LEFT TO FEAST ON THE GALAXY IT BUILT, 704 00:41:51,800 --> 00:41:56,067 EATING THE DEAD REMAINS OF STARS AND PLANETS. 705 00:41:56,067 --> 00:41:58,433 Oluseyi: THE ORBITS OF THE STARS DECAY, 706 00:41:58,433 --> 00:42:01,267 AND THEY FALL IN TOWARD THE SUPERMASSIVE BLACK HOLE. 707 00:42:01,267 --> 00:42:04,167 AND IT ULTIMATELY IT'S THOUGHT GALAXIES LIKE THE MILKY WAY 708 00:42:04,167 --> 00:42:06,967 WILL JUST FORM ONE SUPERMASSIVE BLACK HOLE. 709 00:42:09,167 --> 00:42:10,567 Krauss: IN LITERATURE, 710 00:42:10,567 --> 00:42:12,500 BEGINNINGS AND ENDINGS ARE ALWAYS TIED TOGETHER, 711 00:42:12,500 --> 00:42:15,100 BUT THE SAME IS TRUE FOR OUR GALAXY'S BLACK HOLE. 712 00:42:15,100 --> 00:42:16,433 IT IS QUITE POSSIBLE THAT, 713 00:42:16,433 --> 00:42:19,100 WITHOUT THE FORMATION OF THE BLACK HOLE AT ITS CENTER, 714 00:42:19,100 --> 00:42:21,500 OUR GALAXY WOULD NOT HAVE COALESCED AROUND IT 715 00:42:21,500 --> 00:42:23,100 AND HAVE THE PROPERTIES IT HAS. 716 00:42:23,100 --> 00:42:24,900 BUT THE ULTIMATE FUTURE OF OUR GALAXY 717 00:42:24,900 --> 00:42:27,400 IS TO COLLAPSE INTO A MASSIVE BLACK HOLE. 718 00:42:27,400 --> 00:42:30,200 SO, IN THAT SENSE, THE BLACK HOLE MAY BE RESPONSIBLE 719 00:42:30,200 --> 00:42:31,900 FOR THE BEGINNING OF OUR GALAXY, 720 00:42:31,900 --> 00:42:35,133 AND IT'LL DEFINITELY ULTIMATELY BE RESPONSIBLE FOR ITS DEATH. 721 00:42:37,500 --> 00:42:41,100 Narrator: OUR GALAXY IS MAGNIFICENT. 722 00:42:41,100 --> 00:42:45,333 ALL THIS, EVERYTHING WE SEE IN OUR NIGHT SKY, 723 00:42:45,333 --> 00:42:46,700 COULD BE THE RESULT 724 00:42:46,700 --> 00:42:50,433 OF ONE OF THE MOST FEARSOME OBJECTS IN THE UNIVERSE -- 725 00:42:50,433 --> 00:42:54,967 A SUPERMASSIVE BLACK HOLE THAT COULD'VE BEEN OUR CREATOR 726 00:42:54,967 --> 00:42:58,400 AND WILL BE THE DESTROYER OF OUR GALAXY 727 00:42:58,400 --> 00:43:02,167 AND ALL THE GALAXIES IN THE UNIVERSE.