WEBVTT 00:00:18.281 --> 00:00:20.361 Brian Cox: Our universe is an enigma, 00:00:23.321 --> 00:00:26.321 an endless, inexhaustible paradox. 00:00:29.401 --> 00:00:30.601 It's largely... 00:00:33.041 --> 00:00:35.761 A dark, cold, and lifeless ocean. 00:00:44.121 --> 00:00:45.281 But within this ocean, 00:00:47.761 --> 00:00:53.761 there are islands... Blazing with light. 00:00:59.521 --> 00:01:03.601 Galaxies, trillions of them, 00:01:11.961 --> 00:01:16.121 Each one, home to hundreds of billions of stars, 00:01:20.201 --> 00:01:22.001 and around many of these stars, 00:01:22.841 --> 00:01:24.401 there are planets, 00:01:26.161 --> 00:01:27.881 alien worlds, 00:01:29.601 --> 00:01:33.001 each incomprehensibl y strange. 00:01:37.441 --> 00:01:40.321 There are trillions of planets in our universe 00:01:43.441 --> 00:01:44.441 and one of them 00:01:47.841 --> 00:01:52.721 nurtured beings capable of contemplating this cosmic drama, 00:01:54.321 --> 00:01:56.441 miraculously improbable, 00:01:59.641 --> 00:02:04.641 brief candles flickering against the eternal night. 00:02:10.961 --> 00:02:12.961 As darkness begins to fall, 00:02:13.041 --> 00:02:16.001 if you know that all those points of light 00:02:16.081 --> 00:02:20.241 that appear one by one in the darkening sky are distant suns, 00:02:20.321 --> 00:02:22.841 then it's impossible not to be overwhelmed 00:02:22.921 --> 00:02:25.961 at the sheer scale and majesty of it all. 00:02:28.361 --> 00:02:31.361 The universe is infinite in all directions, 00:02:31.441 --> 00:02:34.001 and terrifying in all directions. 00:02:36.401 --> 00:02:40.201 But if you can overcome your fear, then questions arise. 00:02:40.281 --> 00:02:42.761 And surely the most profound question of all is, 00:02:42.841 --> 00:02:45.281 ”how did all this come to be here?” 00:02:45.361 --> 00:02:48.961 That's a question that's defined much of human history. 00:02:49.041 --> 00:02:51.761 But it's only in the last century or so 00:02:51.841 --> 00:02:55.401 that we've had the intellectual and technical tools 00:02:55.481 --> 00:02:58.881 to interrogate nature directly in search of an answer. 00:03:01.321 --> 00:03:04.601 And we've found that it looks, for all the world, 00:03:04.681 --> 00:03:07.361 like there was a first moment in time, 00:03:08.081 --> 00:03:12.521 a beginning to the universe 13.8 billion years ago, the big bang. 00:03:25.841 --> 00:03:28.601 For all the world, but not quite, 00:03:30.121 --> 00:03:33.641 because we've begun to suspect that there's more to it, 00:03:33.721 --> 00:03:37.721 and we've embarked on a heroic quest to search for 00:03:37.801 --> 00:03:41.681 and to explore the time before the dawn. 00:03:56.321 --> 00:03:59.681 Neil Armstrong: [Can see everything quite clearly. The light... 00:03:59.841 --> 00:04:02.601 It has a stark beauty all its own. 00:04:11.801 --> 00:04:13.401 B uzz a ld ri n: Magnificent desolation. 00:04:14.841 --> 00:04:17.081 - Beautiful view. - Armstro n g: Isn't that something? 00:04:31.561 --> 00:04:34.281 William an ders: For all the people back on earth, 00:04:34.361 --> 00:04:36.001 the crew oprollo 8 00:04:36.641 --> 00:04:39.161 has a message that we would like to send to you. 00:04:43.561 --> 00:04:47.601 In the beginning, god created the heaven and the earth. 00:04:48.801 --> 00:04:52.241 And the earth was without form and void, 00:04:53.521 --> 00:04:56.041 and darkness was upon the face of the deep. 00:04:57.641 --> 00:05:01.401 And god said, ”let there be light'j 00:05:04.561 --> 00:05:06.161 and there was light. 00:05:11.161 --> 00:05:14.241 And god saw the light that it was good. 00:05:20.201 --> 00:05:22.841 Cox: Since we first became conscious of ourselves, 00:05:28.241 --> 00:05:33.281 We've looked to the heavens, to those mysterious lights... 00:05:39.521 --> 00:05:41.041 Searching for answers. 00:05:44.441 --> 00:05:45.761 What is the universe? 00:05:47.561 --> 00:05:49.641 How did it come to be? 00:05:50.681 --> 00:05:53.241 And what is our place in the cosmos? 00:05:56.961 --> 00:05:58.321 Cox: We sometimes doubt 00:05:58.401 --> 00:06:01.121 the creation stories that our ancestors told. 00:06:06.401 --> 00:06:09.961 But those ancient myths conceal a profound truth. 00:06:14.121 --> 00:06:19.041 The clues to the origins of everything can be found out there... 00:06:28.921 --> 00:06:35.401 In light which ripples to us from beyond the stars. 00:06:51.001 --> 00:06:54.801 If we 're going to dare to know about the origin of the universe, 00:06:54.881 --> 00:06:56.801 then we have to have some evidence. 00:06:56.881 --> 00:07:00.921 And the connection we have with the deep past is light. 00:07:07.321 --> 00:07:10.481 See, light travels very slowly on the universal scale, 00:07:10.601 --> 00:07:13.041 only 786, 000 miles a second. 00:07:14.561 --> 00:07:17.601 It takes light eight minutes to journey from the sun to the earth. 00:07:19.801 --> 00:07:23.561 It takes four years for light to journey from the next nearest star. 00:07:23.641 --> 00:07:28.161 And that means we see that star as it was four years in the past. 00:07:28.681 --> 00:07:31.161 So, the further out into the universe we look, 00:07:31.241 --> 00:07:33.241 the further back in time we look. 00:07:33.321 --> 00:07:37.681 And because we can look way out into the distant universe, 00:07:37.761 --> 00:07:41.481 we can look back towards the beginning of time. 00:07:43.521 --> 00:07:45.481 Man 1: Go ahead, Charlie. 00:07:45.881 --> 00:07:47.541 Man 2: Okay, we have a go for release, 00:07:47.561 --> 00:07:48.921 and we 're gonna be a minute late. 00:07:49.281 --> 00:07:51.121 0ka y, Charlie. 00:07:51.201 --> 00:07:53.841 Cox: In the quest to find the origin of the universe, 00:07:55.521 --> 00:07:57.441 we need a time machine. 00:07:58.201 --> 00:07:59.801 Man 2: This is discovery. 00:08:04.401 --> 00:08:06.401 Man 1: We concur, Charlie. 00:08:07.881 --> 00:08:10.281 Cox: A telescope so powerful, 00:08:10.361 --> 00:08:13.721 that can peer out so far into the universe, 00:08:13.801 --> 00:08:17.521 that it can capture the most ancient light... 00:08:19.921 --> 00:08:22.801 The telescope's released. 00:08:24.561 --> 00:08:26.281 Cox: And carry us back... 00:08:29.121 --> 00:08:31.201 Towards the dawn of time. 00:08:32.401 --> 00:08:34.241 Man 1: Okay, Charlie. 00:08:46.001 --> 00:08:47.881 Cox: The hubble space telescope 00:08:47.961 --> 00:08:50.441 has taken us on an odyssey through the universe, 00:08:59.921 --> 00:09:09.961 Revealing its gods... And monsters. 00:09:16.281 --> 00:09:18.961 Our universe is a place of beauty... 00:09:24.881 --> 00:09:26.161 And terror. 00:09:29.801 --> 00:09:33.601 Hubble has shown us visions of sublime creation... 00:09:35.641 --> 00:09:38.961 And images of awesome destruction, 00:09:41.641 --> 00:09:44.921 illuminating our journey backwards in time... 00:09:48.481 --> 00:09:50.001 Towards the dawn. 00:09:55.961 --> 00:09:59.401 The Orion nebula, a stellar nursery, 00:10:01.361 --> 00:10:05.841 clouds of gas nurturing newborn stars in the milky way. 00:10:06.961 --> 00:10:12.881 An image brought to us by light that left the nebula 7,300 years ago. 00:10:17.561 --> 00:10:18.841 The pillars of creation, 00:10:19.641 --> 00:10:23.361 towering, delicate structures, light years tall, 00:10:24.761 --> 00:10:27.401 7, 000 years ago. 00:10:33.561 --> 00:10:34.881 The Andromeda galaxy, 00:10:36.561 --> 00:10:39.721 a glittering island of a trillion suns, 00:10:41.241 --> 00:10:43.721 2.5 million years ago. 00:10:50.521 --> 00:10:53.489 A cosmic Rose, 00:10:53.513 --> 00:10:56.481 galaxies colliding in a celestial dance, 00:11:00.921 --> 00:11:03.481 300 million years ago. 00:11:26.121 --> 00:11:29.561 But hubble's voyage has taken us even further out 00:11:29.641 --> 00:11:31.881 into the uncharted ocean of space, 00:11:41.961 --> 00:11:44.801 Ever deeper into the darkness, 00:11:51.201 --> 00:11:54.841 Glimpsing countless ancient and faraway galaxies. 00:12:02.481 --> 00:12:05.441 Wild, and primitive shoals of stars, 00:12:08.201 --> 00:12:10.961 lighting the way to their primordial past, 00:12:34.321 --> 00:12:38.961 Until, finally, hubble approached the farthest shore, 00:12:49.881 --> 00:12:52.281 A galaxy near the dawn of time. 00:13:02.161 --> 00:13:05.001 This is a galaxy called gn—z7 7, 00:13:05.601 --> 00:13:09.321 and it is one of the most distant galaxies we've ever seen. 00:13:09.641 --> 00:13:12.681 This is light from some of the first stars in the universe. 00:13:12.761 --> 00:13:17.561 It began itsjourney only 400 million years after the big bang, 00:13:18.081 --> 00:13:22.601 and it's taken 13.4 billion years to reach us. 00:13:23.161 --> 00:13:27.041 When you think about that, this light journeyed through the universe, 00:13:27.521 --> 00:13:32.281 and after nine billion years of itsjourney, the earth formed. 00:13:33.241 --> 00:13:36.281 And then, during the whole history of our planet, 00:13:36.361 --> 00:13:40.281 it completed the last third of itsjourney and entered our telescopes. 00:13:40.721 --> 00:13:44.281 So, this is an image from the edge of time. 00:14:02.681 --> 00:14:06.401 Gn—z7 7 was one of the very first galaxies, 00:14:07.721 --> 00:14:11.721 formed at a time when the universe itself was taking shape, 00:14:13.921 --> 00:14:15.841 shortly after the big bang. 00:14:22.921 --> 00:14:26.921 Gn—z7 7 was a strange galaxy by today's standards. 00:14:34.281 --> 00:14:37.801 T wenty-five times smaller than the milky way, 00:14:46.281 --> 00:14:49.401 But filled with enormous, violent stars. 00:15:20.001 --> 00:15:22.961 Lurking alongside these volatile giants, 00:15:24.521 --> 00:15:26.521 there were other things, 00:15:27.481 --> 00:15:31.321 delicate objects struggling in the maelstrom, 00:15:39.721 --> 00:15:42.761 Some of the first planets in the universe. 00:15:46.161 --> 00:15:48.721 These were strange, primordial worlds, 00:15:52.801 --> 00:15:56.761 and over the horizon of one of them, a sun Rose, 00:16:15.161 --> 00:16:18.481 Marking a new chapter in the history of the universe, 00:16:24.921 --> 00:16:28.921 The beginnings of a relationship between stars and planets... 00:16:34.121 --> 00:16:37.241 That would, billions of years later, 00:16:38.481 --> 00:16:40.361 on a faraway world, 00:16:41.721 --> 00:16:44.441 lead to the origin of life. 00:17:04.041 --> 00:17:08.481 Now, we don't know when or where the first dawn broke in the universe. 00:17:11.161 --> 00:17:15.441 But what we do know is that the first dawn was not the first moment. 00:17:15.521 --> 00:17:18.201 The stars and planets had to come from somewhere. 00:17:18.681 --> 00:17:23.441 So, the first dawn was preceded by long, dark night. 00:17:31.561 --> 00:17:35.481 Astronomers call this era the cosmic dark ages. 00:17:40.081 --> 00:17:43.801 If we continue to journey back in time, 00:17:43.881 --> 00:17:46.841 we 'd see shadows fall across the universe. 00:17:52.721 --> 00:17:55.161 The galaxies would disappear. 00:17:57.761 --> 00:18:04.681 The first primitive stars would be extinguished... One by one... 00:18:14.481 --> 00:18:19.521 And darkness truly would be upon the face of the deep. 00:18:21.921 --> 00:18:27.361 Here in the impenetrable gloom of the cosmic dark ages, 00:18:29.281 --> 00:18:32.841 our quest to understand the origins of the universe... 00:18:34.641 --> 00:18:36.001 Would seem to end. 00:18:48.561 --> 00:18:53.401 So, how can we peer into the cosmic dark ages to explore the origin of the universe? 00:18:55.921 --> 00:18:57.721 Well, perhaps counter-intuitively, 00:18:57.801 --> 00:19:00.561 the light from the stars can still guide us 00:19:00.641 --> 00:19:04.481 because that starlight has been travelling across the universe 00:19:04.561 --> 00:19:06.841 for millions or even billions of yea rs to reach us, 00:19:07.361 --> 00:19:11.761 and information about the way the universe has changed and evolved 00:19:11.841 --> 00:19:14.481 becomes imprinted in that starlight. 00:19:31.681 --> 00:19:34.921 The stars have illuminated our voyage through time. 00:19:41.241 --> 00:19:44.841 But their light can't guide us directly across the dark ages. 00:19:46.841 --> 00:19:51.201 Instead, their light can be used to build maps of the universe 00:19:52.281 --> 00:19:53.721 in space and time... 00:19:56.161 --> 00:19:58.561 That allow us to navigate... 00:20:01.641 --> 00:20:03.921 Towards the moment of creation. 00:20:32.561 --> 00:20:34.681 Cox: And the most valuable light of all 00:20:37.361 --> 00:20:43.641 comes from very particular stars in the spectacular swansong of their lives. 00:21:00.561 --> 00:21:03.361 Stars exist in a permanent state of conflict 00:21:03.441 --> 00:21:06.561 because the force of gravity is relentless. 00:21:06.641 --> 00:21:11.361 Left to its own devices, it will crush anything and everything without limit. 00:21:11.921 --> 00:21:15.521 But fortunately, other forces come into play. 00:21:15.601 --> 00:21:18.001 As a star collapses, its core heats up 00:21:18.081 --> 00:21:20.961 and turns into a giant nuclear fusion reactor. 00:21:21.041 --> 00:21:24.721 Hydrogen is converted into helium that releases energy 00:21:24.801 --> 00:21:28.081 which creates a pressure which holds the star up. 00:21:29.041 --> 00:21:32.201 But stars like our sun burn hundreds of millions 00:21:32.281 --> 00:21:35.721 of tons of hydrogen into helium every second. 00:21:35.801 --> 00:21:40.321 And although they are big, they're not infinite in size. 00:21:40.401 --> 00:21:43.881 Stars, just like human beings, have a lifetime. 00:21:43.961 --> 00:21:47.281 They are subject to the relentless march of time. 00:21:47.361 --> 00:21:51.201 And for stars like our sun, the collapse continues 00:21:51.281 --> 00:21:55.881 until it produces a new and exotic type of star 00:21:55.961 --> 00:21:57.401 known as a white dwarf. 00:22:08.961 --> 00:22:11.441 White dwarfs are strange beasts, 00:22:15.561 --> 00:22:17.801 the fading remains of stars, 00:22:21.881 --> 00:22:24.921 super dense, planetary-sized cores, 00:22:25.761 --> 00:22:29.441 usually composed entirely of carbon and oxygen. 00:22:32.841 --> 00:22:36.441 Stars that were once a million times the size of our planet, 00:22:37.961 --> 00:22:41.081 crushed to the size of the earth, 00:22:42.961 --> 00:22:46.441 subjecting the carbon to extreme pressures, 00:22:47.761 --> 00:22:52.441 and making white dwarfs, in effect, stellar diamonds. 00:22:56.041 --> 00:22:58.961 These diamond stars are critically balanced, 00:22:59.801 --> 00:23:03.281 able to resist the relentless inwards pull of gra vity. 00:23:04.401 --> 00:23:05.801 But only just. 00:23:09.881 --> 00:23:13.321 And that can make them ticking time bombs. 00:23:26.121 --> 00:23:28.481 In 2078, hubble was in orbit. 00:23:32.281 --> 00:23:36.961 The telescope focused on a galaxy far, far away, 00:23:51.961 --> 00:23:54.281 Hunting for a distant white dwarf 00:23:54.361 --> 00:23:58.841 that we knew was coming to the end of its extraordinary life. 00:24:07.481 --> 00:24:11.281 For millions of years, the white dwarf had remained hidden, 00:24:28.281 --> 00:24:31.281 Locked in orbit around a much biggest star, 00:24:35.361 --> 00:24:36.601 a red giant. 00:24:49.921 --> 00:24:52.001 As they circled each other, 00:24:52.081 --> 00:24:56.921 the white dwarf's gravity drew in gas and plasma from the red giant. 00:25:05.281 --> 00:25:07.321 The mass of the white dwarf increased... 00:25:11.321 --> 00:25:13.601 Until it approached a critical limit... 00:25:19.481 --> 00:25:21.761 Known as the chandrasekhar mass... 00:25:26.641 --> 00:25:28.241 And surpassed it... 00:25:29.961 --> 00:25:34.001 Triggering a colossal thermonuclear reaction. 00:25:49.561 --> 00:25:51.361 The white dwarf detonated... 00:25:52.721 --> 00:25:57.561 In a gigantic explosion called a supernova 00:26:07.081 --> 00:26:09.481 That millions of light years away, 00:26:12.961 --> 00:26:15.121 was detected by hubble. 00:26:18.681 --> 00:26:20.121 That white dwarf star, 00:26:20.201 --> 00:26:23.281 or to be more precise, the supernova that it became, has a name. 00:26:24.921 --> 00:26:27.801 It's called sn 2078gv. 00:26:28.521 --> 00:26:33.041 And even though it is 70 million light years away, 00:26:33.121 --> 00:26:36.681 it is so bright that we could make a movie on it. 00:26:40.201 --> 00:26:43.401 I mean, imagine now, this is a star the size of a planet 00:26:43.481 --> 00:26:46.361 ending its life with a flash of light 00:26:47.441 --> 00:26:50.681 that's as bright as five billion suns. 00:26:53.281 --> 00:26:56.961 Now, although supernova like these only shine for a few days, 00:26:57.041 --> 00:27:01.441 they cast a profound light out across the universe. 00:27:06.481 --> 00:27:09.481 We've given a name to the sorts of superno va hubble saw. 00:27:11.561 --> 00:27:14.201 They're called type 7a supernovae 00:27:17.361 --> 00:27:21.961 and they're common enough to allow us to map the evolution of the universe. 00:27:28.681 --> 00:27:32.201 Type 1A supernovae really are nature's gift to us 00:27:32.561 --> 00:27:35.241 because they all explode in the same way. 00:27:35.321 --> 00:27:37.801 That means that they all shine with the same brightness. 00:27:38.201 --> 00:27:42.201 And that means that if we see one that's dimmer, it must be farther away. 00:27:42.281 --> 00:27:43.681 And that allows us to measure 00:27:43.761 --> 00:27:46.401 the distance to the galaxy that contains the supernova. 00:27:47.001 --> 00:27:48.641 And because they shine so bright, 00:27:48.721 --> 00:27:52.521 we can see them tens of billions of light years away. 00:27:52.601 --> 00:27:54.881 That means that we can measure the distance to galaxies 00:27:54.961 --> 00:27:59.681 all the way out towards the edge of the observable universe. 00:28:04.681 --> 00:28:08.201 But there's other information encoded in the light. 00:28:33.841 --> 00:28:36.681 When we look at the light from distant supernova explosions, 00:28:37.761 --> 00:28:41.881 we see something very interesting, and very surprising, 00:28:41.961 --> 00:28:44.321 because the light from every single supernova 00:28:44.401 --> 00:28:48.081 that's not in our neighbourhood is redder that it should be. 00:28:48.161 --> 00:28:51.081 The further away the supernova, the redder the light. 00:28:51.161 --> 00:28:52.481 It's called a redshift. 00:28:52.841 --> 00:28:55.241 Now, light has a wavelength, 00:28:55.321 --> 00:28:59.041 and the longer the wavelength, the redder the light. 00:28:59.121 --> 00:29:00.681 So, the explanation is that, 00:29:00.761 --> 00:29:05.001 during the time the light has been travelling from the supernova to us, 00:29:05.081 --> 00:29:09.961 space itself has been stretching, and that stretched the light. 00:29:10.521 --> 00:29:14.361 And that means that the universe is expanding. 00:29:18.481 --> 00:29:22.761 In our quest to find the origin of the universe, this is a vital clue. 00:29:25.281 --> 00:29:27.761 Because if the universe is expanding today, 00:29:28.841 --> 00:29:32.201 then, tomorrow, everything will be farther apart. 00:29:37.201 --> 00:29:42.081 And it follows that, yesterday, everything was closer together. 00:29:44.241 --> 00:29:46.601 So, if we want to understand how it all began, 00:29:50.281 --> 00:29:52.161 we have to wind back time 00:29:55.081 --> 00:29:57.321 through billions of yesterdays. 00:30:01.961 --> 00:30:05.441 We have to go back to a time before the earth and the sun, 00:30:17.321 --> 00:30:20.681 To a time before the galaxies, 00:30:26.441 --> 00:30:30.441 And all the while, the universe is shrinking, 00:30:33.281 --> 00:30:39.281 getting ever smaller, denser, and hotter, 00:30:40.521 --> 00:30:45.161 until we arrive at the most famous moment in the history of the universe. 00:31:10.001 --> 00:31:12.601 Our universe is a place of infinite variety. 00:31:20.721 --> 00:31:23.601 There are galaxies of exquisite beauty, 00:31:27.761 --> 00:31:30.521 stars of stupendous power, 00:31:34.961 --> 00:31:40.001 and planets... Countless brave new worlds. 00:31:57.001 --> 00:31:59.521 Galaxies, stars, and planets 00:31:59.601 --> 00:32:02.841 are the things that make our universe remarkable. 00:32:09.441 --> 00:32:13.561 They are the things that make it more than a barren expanse. 00:32:22.521 --> 00:32:26.441 How did a universe of light and life 00:32:26.521 --> 00:32:30.441 emerge from the cataclysm of the big bang? 00:32:35.401 --> 00:32:37.601 Unfortunately, we don't know. 00:32:37.681 --> 00:32:40.721 We don't even know if the universe had a beginning. 00:32:40.801 --> 00:32:44.481 But we do know a great deal about how the universe evolved 00:32:44.561 --> 00:32:48.001 from a very different state a long time in the past. 00:32:48.081 --> 00:32:50.881 We know that 13.8 billion years ago, 00:32:50.961 --> 00:32:55.081 this space that I'm standing in now and the space you're standing in now 00:32:55.161 --> 00:32:58.521 and all the space out to the edge of the observable universe 00:32:58.601 --> 00:33:03.441 containing two trillion galaxies was very hot and very dense, 00:33:03.521 --> 00:33:05.681 and has been expanding ever since. 00:33:06.161 --> 00:33:10.921 Now, that implies that way back, everything was closer together, 00:33:11.001 --> 00:33:14.041 everything was contained in a very small speck. 00:33:14.121 --> 00:33:16.601 But how small was that speck? 00:33:17.201 --> 00:33:18.761 How did it come to be? 00:33:19.121 --> 00:33:23.321 Well, we used to think that the universe emerged in that state, 00:33:23.401 --> 00:33:26.041 very hot and very dense at the beginning of time, 00:33:26.121 --> 00:33:28.841 and we used to call that the big bang. 00:33:28.921 --> 00:33:34.321 But now, we strongly suspect that the universe existed before that. 00:33:34.401 --> 00:33:39.881 And in that sense, it is possible to speak of a time before the big bang. 00:33:50.081 --> 00:33:53.841 So, what was the universe like before the big bang? 00:33:58.361 --> 00:34:02.561 The first thing to say is that it was very strange. 00:34:07.641 --> 00:34:11.441 There was no matter. 00:34:11.521 --> 00:34:14.961 All that existed was spacetime 00:34:15.041 --> 00:34:17.961 and energy, an ocean of energy, 00:34:19.201 --> 00:34:23.321 almost still, but gently rippling. 00:34:33.881 --> 00:34:35.281 Before the big bang, 00:34:35.361 --> 00:34:39.841 the universe was a cold, alien, featureless place. 00:34:43.761 --> 00:34:48.201 Picture it as a near still ocean of energy filling the void. 00:34:49.081 --> 00:34:51.321 Although it contained no structures, 00:34:51.401 --> 00:34:56.561 that energy did have an effect on space. It caused it to stretch. 00:34:59.361 --> 00:35:02.001 Not the gentle expansion we see today, 00:35:02.081 --> 00:35:05.281 but unimaginably violent expansion. 00:35:05.361 --> 00:35:08.201 That expansion is known as inflation. 00:35:12.201 --> 00:35:17.481 Think of a speck, a tiny, insignificant patch of space, 00:35:23.321 --> 00:35:27.881 Insignificant, except that many billions of years later, 00:35:28.561 --> 00:35:33.441 this speck would have grown to become our entire observable universe. 00:35:36.881 --> 00:35:41.241 The speck expanded at a phenomenal rate, 00:35:41.321 --> 00:35:43.801 an exponential expansion... 00:35:47.001 --> 00:35:48.841 That lasted... 00:35:49.881 --> 00:35:55.481 Just a few billion, billion, billion, billionths of a second. 00:35:59.281 --> 00:36:01.801 Now, the speck continued to expand 00:36:01.881 --> 00:36:04.161 until it was about the size of this cave. 00:36:04.241 --> 00:36:07.761 And then, inflation drew rapidly to a close, 00:36:07.841 --> 00:36:11.081 and all the energy in that ocean that was driving the expansion 00:36:11.161 --> 00:36:14.921 was dumped into space and formed the ingredients 00:36:15.001 --> 00:36:18.041 of everything in our observable universe. 00:36:18.121 --> 00:36:21.961 I mean, imagine that. A space about this size 00:36:22.041 --> 00:36:26.281 filled with enough energy to form two trillion galaxies. 00:36:27.321 --> 00:36:28.961 That's what we call the big bang. 00:36:39.041 --> 00:36:41.281 So the big bang was not, 00:36:41.361 --> 00:36:44.881 as we commonly imagine, some kind of explosion. 00:36:47.881 --> 00:36:52.521 It was actually a transformation of energy into matter. 00:36:59.801 --> 00:37:03.881 And the fossilised remains of these momentous events, 00:37:03.961 --> 00:37:08.481 the memory of the rippling ocean of energy that drove inflation 00:37:08.561 --> 00:37:11.681 became imprinted into our universe. 00:37:13.121 --> 00:37:17.561 In fact, these fossilised ripples shaped our universe, 00:37:18.521 --> 00:37:23.681 influencing where each galaxy and star emerged, 00:37:23.761 --> 00:37:26.881 each planet and moon. 00:37:31.161 --> 00:37:33.481 But how do we know all this? 00:37:36.921 --> 00:37:39.841 How do we know that there was a big bang? 00:37:41.321 --> 00:37:43.321 How do we know there were 00:37:43.401 --> 00:37:47.041 ripples in an ocean of energy before the big bang? 00:37:54.241 --> 00:37:55.761 The answer is... 00:37:58.481 --> 00:38:00.121 Cox: That we've seen them. 00:38:52.681 --> 00:38:55.721 Cox: Planck scanned the entire cosmos 00:38:58.041 --> 00:38:59.601 looking for light. 00:39:10.841 --> 00:39:14.121 Not light from galaxies or stars, 00:39:16.961 --> 00:39:19.681 but light from the beginning of time. 00:39:48.121 --> 00:39:50.961 This is a photograph of the distant past. 00:39:51.321 --> 00:39:53.361 It's the most ancient light in the universe. 00:39:53.441 --> 00:39:58.401 This is light that's travelled for almost 13.8 billion years to reach us. 00:39:58.921 --> 00:40:01.121 It's a photograph of the entire sky, 00:40:01.201 --> 00:40:03.329 a celestial sphere, if you like, 00:40:03.353 --> 00:40:05.481 every direction that we can look, 00:40:05.561 --> 00:40:08.321 and it's been laid flat so we can see it all. 00:40:09.121 --> 00:40:12.321 It's called the cosmic microwave background radiation, 00:40:12.401 --> 00:40:14.681 and it's an almost featureless glow. 00:40:14.761 --> 00:40:18.161 There were no stars and no galaxies in this universe. 00:40:18.961 --> 00:40:20.561 Now, you might ask the question, 00:40:20.641 --> 00:40:23.401 "well, if there were no stars and there were no galaxies, 00:40:23.481 --> 00:40:25.441 "then, where's the light coming from?" 00:40:25.521 --> 00:40:29.361 The answer is, the light is coming from the universe itself. 00:40:29.441 --> 00:40:32.681 Because this is only a few hundred thousand years after the big bang, 00:40:32.761 --> 00:40:35.041 so, the universe was hot. 00:40:35.121 --> 00:40:39.681 So, what you're seeing here is the afterglow of the big bang. 00:40:55.641 --> 00:41:00.481 The most revealing thing about this picture is the detail, 00:41:08.561 --> 00:41:09.881 The variation. 00:41:21.921 --> 00:41:23.361 This pattern is one of 00:41:23.441 --> 00:41:26.921 the most important discoveries in all of human history 00:41:27.001 --> 00:41:30.121 because it represents one of the necessary steps 00:41:30.201 --> 00:41:32.521 in the story of how we came to be here. 00:41:42.641 --> 00:41:46.881 See, that still ocean of energy that drove the rapid expansion 00:41:46.961 --> 00:41:51.841 of space during inflation could not be entirely still. 00:41:52.161 --> 00:41:54.241 There had to be ripples in the ocean. 00:41:54.321 --> 00:41:58.441 It's a consequence of the laws of nature, as we understand them. 00:42:04.801 --> 00:42:08.601 And those ripples in the ocean were imprinted into our universe 00:42:08.681 --> 00:42:12.761 through the big bang that emerged as those areas 00:42:12.841 --> 00:42:16.081 of slightly different density in the young universe. 00:42:17.961 --> 00:42:21.721 And then, as the universe continued to expand and cool, 00:42:21.801 --> 00:42:24.481 the regions that were slightly denser collapsed 00:42:24.561 --> 00:42:27.761 to form the first stars and galaxies. 00:42:28.641 --> 00:42:31.921 50, without those ripples, we would not exist. 00:42:36.841 --> 00:42:40.641 But there's one more extraordinary thing about these ripples. 00:42:41.841 --> 00:42:44.641 And that's the fact that we predicted them 00:42:44.721 --> 00:42:47.441 before we knew they existed. 00:42:49.561 --> 00:42:53.881 And then, we ventured into space to test our theory. 00:42:54.881 --> 00:42:59.601 Planck's observation of the afterglow of the big bang is strong evidence 00:42:59.681 --> 00:43:02.641 for our outlandish creation saga, 00:43:04.441 --> 00:43:10.281 the story of the speck, the ripples, and inflation. 00:43:16.081 --> 00:43:19.001 These ripples, then, are the seeds of our creation, 00:43:19.081 --> 00:43:21.921 and we dared to guess that they exist 00:43:22.001 --> 00:43:24.881 from our vantage point here, on a small planet 00:43:24.961 --> 00:43:29.241 13.8 billion years after the moment of creation. 00:43:30.081 --> 00:43:35.281 And then, because we're scientists, we decided to launch a spacecraft 00:43:35.361 --> 00:43:39.961 out into space, and capture the oldest light in the universe. 00:43:40.041 --> 00:43:43.241 And we saw that our guess was correct. 00:43:44.001 --> 00:43:46.921 We dared to imagine a time before the dawn, 00:43:47.001 --> 00:43:51.961 and we proved that our creation story is not a myth. 00:43:59.321 --> 00:44:05.161 So, here is the creation story as told by science. 00:44:08.721 --> 00:44:11.761 In the beginning, there was an ocean of energy 00:44:12.361 --> 00:44:16.561 that drove a rapid expansion of space known as inflation. 00:44:18.561 --> 00:44:20.041 There were ripples in the ocean. 00:44:25.041 --> 00:44:29.961 As inflation ended, the ocean of energy was converted into matter, 00:44:31.801 --> 00:44:33.321 then the big bang. 00:44:40.081 --> 00:44:43.881 And the pattern of the ripples was imprinted into our universe... 00:44:45.401 --> 00:44:48.241 As regions of slightly different density 00:44:48.321 --> 00:44:53.441 in the hydrogen and helium gas that formed shortly after the big bang. 00:45:14.601 --> 00:45:16.921 The denser regions of gas collapsed... 00:45:20.881 --> 00:45:22.841 To form the first stars... 00:45:36.441 --> 00:45:37.921 And the first galaxies. 00:45:42.161 --> 00:45:44.201 And nine billion years later, 00:45:47.641 --> 00:45:50.841 a new star formed in the milky way... 00:45:53.081 --> 00:45:54.721 The sun. 00:46:02.881 --> 00:46:05.601 The star was joined by eight planets... 00:46:07.721 --> 00:46:10.521 Including earth. 00:46:16.601 --> 00:46:21.961 And nearly 73.8 billion years after it all began, 00:46:22.721 --> 00:46:24.721 we emerged... 00:46:26.641 --> 00:46:29.161 Blinking into the light. 00:46:59.241 --> 00:47:01.681 Man: "To see the earth as it truly is, 00:47:01.761 --> 00:47:06.401 ”small and blue and beautiful in that eternal silence where it floats, 00:47:06.481 --> 00:47:09.801 ”is to see ourselves as riders on the earth together, 00:47:10.761 --> 00:47:14.441 ”brothers on that bright loveliness in the eternal cold, 00:47:15.361 --> 00:47:19.241 ”brothers who know now they are truly brothers. ” 00:47:24.601 --> 00:47:26.521 Cox: We all have moments of wonder. 00:47:28.001 --> 00:47:29.681 We all dream. 00:47:31.281 --> 00:47:35.281 Our thoughts float free, soaring across the earth 00:47:36.161 --> 00:47:38.961 and out into a canopy of stars. 00:47:42.881 --> 00:47:47.561 In our most reflective moments, I think we all understand that 00:47:47.641 --> 00:47:51.801 small, though we are, we are connected to the universe. 00:47:53.401 --> 00:47:56.241 We are collections of simple atoms, 00:47:57.881 --> 00:48:00.441 but atoms arranged remarkably, 00:48:03.601 --> 00:48:08.801 with the urge to explore the universe, and to comprehend it, 00:48:14.361 --> 00:48:19.801 And celebrate our own place in this great cosmic saga. 00:48:25.881 --> 00:48:30.201 And if we follow that saga back, it takes us on a pilgrimage... 00:48:34.201 --> 00:48:36.641 To a time before the dawn, 00:48:41.801 --> 00:48:47.441 And to strange ripples that existed in a universe before our own. 00:48:59.761 --> 00:49:02.401 I think we all must wonder about the meaning of it all. 00:49:03.321 --> 00:49:06.041 What does it mean to be human? Why do we exist? 00:49:06.121 --> 00:49:08.001 Why does anything exist at all? 00:49:08.881 --> 00:49:11.921 These do not sound like scientific questions. 00:49:12.001 --> 00:49:15.961 They sound like questions for philosophy or theology, even. 00:49:16.601 --> 00:49:18.721 But I think they are scientific questions 00:49:18.801 --> 00:49:23.681 because they're questions about nature, they're questions about the universe 00:49:24.081 --> 00:49:27.561 and the way to understand the universe is to observe it. 00:49:27.641 --> 00:49:31.561 And we've seen ripples in the most ancient light in the universe, 00:49:31.641 --> 00:49:35.161 laid down by events that happened before the big bang. 00:49:35.241 --> 00:49:37.969 We've seen billions of galaxies written 00:49:37.993 --> 00:49:40.721 across the sky in a giant cosmic web. 00:49:40.801 --> 00:49:44.321 And we've seen thousands of planets orbiting around distant stars, 00:49:44.401 --> 00:49:46.841 worlds beyond imagination. 00:49:47.441 --> 00:49:49.561 Now, the lesson to me is clear. 00:49:49.681 --> 00:49:54.641 We won't answer the deepest questions by being introverted, by looking inwards. 00:49:54.721 --> 00:49:58.561 We will answer them by lifting our gaze above the horizon 00:49:58.641 --> 00:50:02.481 and looking outwards into the universe beyond the stars. 00:50:03.081 --> 00:50:07.601 We used to look to the sky and see only questions. 00:50:07.681 --> 00:50:10.041 Now, we're beginning to see answers. 00:50:43.001 --> 00:50:45.241 Kimberly arcan d: Hubble is a very special telescope. 00:50:45.321 --> 00:50:47.521 It's kind of like the celebrity telescope 00:50:47.601 --> 00:50:49.681 and for a really good reason. 00:50:50.361 --> 00:50:54.681 It was the first time that we were able to launch such a powerful, 00:50:54.761 --> 00:50:56.961 large optical telescope into space. 00:50:59.681 --> 00:51:03.481 Mason: The earth's atmosphere kind of blurs out lots of our images. 00:51:03.561 --> 00:51:05.321 And so, by putting the telescope in space, 00:51:05.401 --> 00:51:09.641 we get these precise, crystal clear images of our universe. 00:51:09.721 --> 00:51:13.601 Man: Three, two, one, and lift-off 00:51:13.681 --> 00:51:17.041 of space shuttle discovery with the hubble space telescope, 00:51:17.121 --> 00:51:19.601 our window on the universe. 00:51:19.721 --> 00:51:23.721 Carole haswell: The feeling that you get when the space shuttle takes off, 00:51:23.801 --> 00:51:28.041 there's just a sort of... The sound and the vibrations, 00:51:28.121 --> 00:51:30.681 it's just incredibly awe-inspiring. 00:51:34.641 --> 00:51:36.441 Man: All rocket boosters have done their job. 00:51:36.721 --> 00:51:38.961 Man 1: Go ahead Charlie. 00:51:39.721 --> 00:51:41.261 Man 2: Okay, we have a go for release, 00:51:41.281 --> 00:51:42.921 and we 're gonna be a minute late. 00:51:59.201 --> 00:52:01.801 Haswell: We were all sort of sitting on the edge of our seats, 00:52:01.881 --> 00:52:03.841 waiting for the very first images 00:52:03.921 --> 00:52:06.961 where hubble is showing us what it can see in the universe, 00:52:07.881 --> 00:52:12.361 and that turned into an unexpectedly long wait. 00:52:15.161 --> 00:52:16.681 Newsreader: Engineers have discovered 00:52:16.761 --> 00:52:19.401 that the giant telescope has a warped mirror, 00:52:19.481 --> 00:52:22.601 which means the images sent back to NASA are distorted. 00:52:24.881 --> 00:52:29.321 Haswell: We had this very, very precisely engineered mirror, 00:52:29.401 --> 00:52:33.921 but it had been very precisely engineered to the wrong shape. 00:52:37.041 --> 00:52:40.601 For the first three years in the life of the hubble, it wasn't producing 00:52:40.681 --> 00:52:43.641 the wonderful images that everyone had expected. 00:52:45.881 --> 00:52:48.921 Haswe ll: The solution was the same solution 00:52:49.001 --> 00:52:52.081 to the fact that, as a kid, I couldn't read the blackboard. 00:52:52.161 --> 00:52:55.801 The solution was basically to fit the telescope 00:52:55.881 --> 00:52:59.801 with corrective optics, or something analogous to spectacles. 00:52:59.881 --> 00:53:02.321 Man: And we have a go for main engine start. 00:53:02.881 --> 00:53:07.401 Five, four, three, two, one, 00:53:08.561 --> 00:53:11.841 and we have lift off lift off of the space shuttle endeavou r 00:53:11.921 --> 00:53:15.361 on an ambitious mission to service the hubble space telescope. 00:53:15.721 --> 00:53:17.961 Jeff Hoffman: It's kind ofamazing that we have to be able 00:53:18.041 --> 00:53:22.801 to position this optical equipment to an accuracy of better than a millimetre, 00:53:22.881 --> 00:53:26.761 something that we 'd have trouble doing even on the ground, in your bare hands. 00:53:27.481 --> 00:53:30.441 Man: Firm handshake with mr hubble's telescope. 00:53:31.161 --> 00:53:33.221 Woman: We copy that... 00:53:33.241 --> 00:53:37.121 The vice president and I wanted to call you and congratulate you 00:53:37.201 --> 00:53:39.681 on one of the most spectacular space missions in our history. 00:53:43.481 --> 00:53:48.201 Arcand: And when hubble opened its eyes after they were corrected, 00:53:48.281 --> 00:53:52.521 the views that we were able to get from that telescope changed forever 00:53:52.601 --> 00:53:57.441 the way we understood and visualised the universe that we live in. 00:54:02.801 --> 00:54:07.121 The pictures are remarkable. The trouble with hubble is over. 00:54:12.521 --> 00:54:15.441 David kaiser: It's really hard to remember what it was like 00:54:15.521 --> 00:54:17.481 before we had the hubble space telescope. 00:54:17.961 --> 00:54:20.761 We've gotten so used to these extraordinary photographs 00:54:20.841 --> 00:54:23.841 of the near, of the far, of the very, very far. 00:54:29.001 --> 00:54:30.961 Mason: I think, any time I look at a hubble image, 00:54:31.041 --> 00:54:32.841 my mind gets blown a little bit. 00:54:34.561 --> 00:54:38.641 I was the kid that had, like, printouts of hubble images in their locker. 00:54:43.801 --> 00:54:48.481 Anybody, whether they have the heart of an astronomer or soul of a poet, 00:54:48.561 --> 00:54:51.241 they're going to find things in the images from hubble 00:54:51.321 --> 00:54:55.201 that just appeal to them from the point of pure wonder. 00:55:06.201 --> 00:55:08.641 Haswell: Hubble has not only done the things 00:55:08.721 --> 00:55:12.041 that people expected and hoped it would, 00:55:12.121 --> 00:55:13.921 but it's actually done a lot of things 00:55:14.001 --> 00:55:16.281 that nobody would have dared to dream of. 00:55:19.561 --> 00:55:20.861 Kaiser: One of the biggest discoveries 00:55:20.881 --> 00:55:23.361 that came from using the hubble space telescope 00:55:23.441 --> 00:55:25.641 is that, not only is our universe getting bigger, 00:55:25.721 --> 00:55:29.641 it's not just expanding and stretching, it's actually getting bigger faster. 00:55:33.121 --> 00:55:37.561 We can well imagine that the universe is going to continue to expand 00:55:37.641 --> 00:55:41.481 and get so big that, eventually, the galaxies will just disappear. 00:55:41.561 --> 00:55:46.281 They'll be so far away from us and moving so rapidly that we have no hope 00:55:46.361 --> 00:55:49.841 of seeing any light from them, and that's a real possibility 00:55:49.921 --> 00:55:51.921 for what could happen in the future. 00:55:55.241 --> 00:55:56.781 Kaiser: We still have these mysteries of 00:55:56.801 --> 00:56:01.401 what's really driving this new phase of accelerated expansion, 00:56:01.481 --> 00:56:04.321 and we're building new tools to try to refine those questions. 00:56:19.641 --> 00:56:23.001 Larry gladney: The hubble telescope which was a marvel for its time 00:56:23.081 --> 00:56:26.201 is really far behind what we would design today. 00:56:30.361 --> 00:56:34.401 It will be completely outclassed by the next generation telescope, 00:56:34.481 --> 00:56:38.761 the James webb space telescope, which will see even deeper than hubble. 00:56:43.001 --> 00:56:47.241 Haswell: And that will give us unprecedented detailed views. 00:56:47.321 --> 00:56:51.241 We can use it to see through some of the very dense, 00:56:51.321 --> 00:56:55.601 murky dust clouds and actually see stars in the process of forming. 00:56:56.881 --> 00:57:01.281 We also can use it to look further and further back in time. 00:57:03.641 --> 00:57:07.161 That's going to be a very, very exciting story which is going to unfold, 00:57:07.241 --> 00:57:09.561 I think, within the next three or four years. 00:57:21.161 --> 00:57:24.481 Hubble is still king because it's still a big observatory 00:57:24.561 --> 00:57:27.561 in comparison to what we've had in space before. 00:57:28.841 --> 00:57:31.801 Hubble is a unique instrument for making discoveries that 00:57:31.881 --> 00:57:34.201 no other telescope could possibly ha ve made. 00:57:39.441 --> 00:57:42.041 I think, when you think about an image of space, 00:57:42.121 --> 00:57:44.361 when you think about space, you think of a hubble image.