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00:00:00Every story has a beginning.
00:00:07Even the story of the universe.
00:00:10Some 13.7 billion years ago,
00:00:14a mysterious event thrust the universe into motion
00:00:18in a big bang.
00:00:23The ultimate creation of every atom,
00:00:26every star, and every galaxy.
00:00:29But this is our story,
00:00:32how for thousands of years
00:00:34we've pieced together a vision of the universe,
00:00:38made sense of it through science,
00:00:41and discovered our place within it.
00:00:44This is our story of everything,
00:00:48from shaman to scientist,
00:00:51beyond the Big Bang.
00:00:59For thousands of years, we've gathered our observations of the heavens
00:01:09into books that would more than fill a library.
00:01:14We've built a vast body of knowledge about our universe.
00:01:17How it all began, how it will end.
00:01:21It's a work in progress.
00:01:23The script is still being written.
00:01:24The ink is still wet on the page.
00:01:26Where do we begin?
00:01:28Let's begin.
00:01:29Let's begin.
00:01:30At the beginning.
00:01:31Let's begin.
00:01:32With the Big Bang.
00:01:33Let's begin.
00:01:34With the Big Bang.
00:01:36The Big Bang.
00:01:37The Big Bang is a theory of cosmic evolution.
00:01:40it's a work in progress the script is still being written the ink is still wet on the page
00:01:48where do we begin let's begin at the beginning let's begin with the big bang
00:02:02the big bang is a theory of cosmic evolution it tells us how the universe evolved how it changed
00:02:09from a split second after whatever brought it into existence and we still don't know what that is
00:02:15until today when you look out at the universe and look at the other distant galaxies you see
00:02:23that they're all fleeing away from us that they're all moving outward at huge velocities
00:02:30you extrapolate that all the way back you see that one time maybe 13 or 14 billion years ago
00:02:36everything that there was must have been compressed into one inconceivably dense point
00:02:44we know we don't have the whole story but we've never had the whole story in the history of physics
00:02:50we've had a series of better and better approximations revealing startlingly more and more beautiful and
00:02:56interesting truths the big bang is our theory for the beginning of the universe but for a long time
00:03:06people either didn't think about the origin of the universe or they assumed the universe had always
00:03:12existed and was everlasting even scientists were reluctant at first to embrace the big bang
00:03:21it was meant to be a derisive term however the big bang is really a contradiction because it was not
00:03:29big and there was no bang it wasn't big because we think that the universe started from a singularity
00:03:35of some sort and there was no bang because there was no air to carry the vibrations so a big bang is in
00:03:42some sense is a misnomer but the name stuck and so has the theory right now i would say that the big bang
00:03:50theory is a solid part of science as we understand it anybody who doesn't accept it is regarded by
00:03:57most of the people in community is essentially a crackpot but acceptance and understanding are two
00:04:03different things the big bang theory doesn't yet provide all the answers science seeks to explain how
00:04:10our universe was born what cosmologists are referring to when they talk about the big bang theory
00:04:16is really only a description of the aftermath of the bang the conventional big bang theory says nothing
00:04:23about what banged why it banged or what happened before it banged right now at this very second
00:04:30we're in the aftermath of the big bang everything we see and hear and taste and smell and touch is the
00:04:41aftermath the big bang is really our evolving expanding universe for us mostly stuck on our rocky little
00:04:54planet the view of the universe begins with earth this is earth silicon and oxygen based with a metallic core
00:05:04the surface is mostly water it teams with life and rotates once every 24 hours while orbiting a star called
00:05:14the sun every 365 days this is the sun mostly hydrogen and helium its surface temperature is nearly 10 000 degrees fahrenheit
00:05:30for energy our sun converts 700 million tons of hydrogen into 695 million tons of helium every second
00:05:44the sun is part of a solar system formed around 4.5 billion years ago that includes earth and seven other
00:05:51orbiting planets from mercury to neptune and it isn't a stationary system
00:05:57our solar system is spinning flying through space at 134 miles per second
00:06:09turning in circles as part of a vast collection of stars and star systems there may be 200 billion stars
00:06:18in this collection called the milky way galaxy an estimated 6 billion of those stars with planetary systems
00:06:26like ours our solar system orbits the center of the milky way on one of its outer arms
00:06:37the milky way is one of more than 125 billion galaxies that make up the visible universe
00:06:44this is the universe
00:06:56it's really really big and it's getting bigger it's expanding
00:07:04if the universe is expanding then it used to be smaller
00:07:08much smaller in fact if we went back in time we could watch it shrink
00:07:21back far enough and the universe would be smaller than a galaxy
00:07:27back and the universe is smaller than our solar system
00:07:30the universe would be smaller than the smallest part of an atom
00:07:36the universe would be smaller than the smallest part of an atom
00:07:4013.7 billion years ago the universe was smaller than the smallest part of an atom
00:07:49unbelievably small
00:07:50then something happened
00:08:00in a flash everything suddenly expanded
00:08:05this was how it all began the first moment of existence what we now call the big bang
00:08:14and that's what we know to be true not because theorists have invented it but because we've
00:08:19all the observations tell us we can predict the abundance of light elements and they agree over
00:08:2510 orders of magnitude with what we see
00:08:29so that fundamental picture that the universe is expanding and emerged out of a hot dense universe
00:08:34the finite time in the past is the big bang picture
00:08:37the theory of the big bang isn't the sort of thing you figure out overnight it takes years
00:08:46centuries of collected wisdom
00:08:50mankind has been thinking about this for a long time
00:08:55even before we realized it we were thinking about it
00:08:59every time we looked up at the stars we were thinking about it
00:09:03how do we know what we now know how did we figure it all out that's the heart of our story
00:09:13the story of how our concept of the universe evolved we stockpile the discoveries of the most
00:09:21brilliant members of our species allowing us however strained and with whatever struggle it involves
00:09:29to slowly ascend the ladder of knowledge maybe compensating for the fact that any one of us
00:09:37is just too stupid to figure it all out
00:09:45so where do we begin
00:09:47today professional astronomers and physicists on campuses like the massachusetts institute of technology
00:10:05and cambridge university in england wage debate about the big bang theory
00:10:10but the conversation began a long time ago before anyone ever heard of the big bang
00:10:19before anyone knew what the heavens really were way before science existed or was even a
00:10:27contemplation in the minds of anybody people were asking questions about origin
00:10:31when early man looked at the sky he saw it dominated by the warming life-giving sun
00:10:48at night he saw the moon and stars
00:10:54this was the universe harsh hostile and chaotic
00:10:59with a drifting sun that shifted across the sky as the seasons went from warm to cold
00:11:07primitive people needed to understand their world in order to survive it
00:11:13people had absolutely no control over nature the balance of the expected and the unexpected
00:11:19made people make nature into gods in order to establish some kind of relationship with them
00:11:29without telescopes or modern observatories
00:11:32primitive people relied on simple structures to help them understand the skies
00:11:40at places like stonehenge in england
00:11:44or chichen itza in mexico
00:11:47they attempted to connect with the heavens
00:11:50the perceived home of the gods
00:11:52these were simple instruments of observation and tools of analysis
00:12:00that helped make sense of the dancing universe
00:12:03the earth we are here in the eastern part of germany some hundred kilometers south of berlin
00:12:09in a little village called gozeck one of the oldest monuments concerning sun moon and stars was found here
00:12:19this is the solar observatory at gozeck it was built seven thousand years ago and was used by the early farmers to tell the time in the year
00:12:28this is europe's oldest known calendar
00:12:45during the winter and summer solstices
00:12:47the shortest and longest days of the year
00:12:50the setting sun lines up with gates in the palisades
00:12:56knowing these dates help these people understand the life-giving sun
00:13:01the night sky is a clock
00:13:07it is a gigantic clock staring you in the face and it allowed the ancients to calculate when to plant
00:13:13when to harvest
00:13:14harvest in other words their very livelihood depended upon their understanding the motion of the sun and the heavens
00:13:24this idea of astronomy predicting the behavior of the natural world based on the motion of the heavens
00:13:31gets mixed up with the dogma of astrology
00:13:34the belief that the motion of the heavens predetermines our fate
00:13:39that a meteor signals military victory
00:13:44a new star the birth of the king
00:13:48back then astronomy was predicting the motion of the stars astrology was predicting how those stars affected
00:13:54us and it's really hard in the ancient mind to separate those two that if you understand
00:14:01the clockwork of the heavens you understand how our fate is going to be
00:14:07astrologers divided the sky into regions as early as the sixth century bc
00:14:14they saw shapes in the stars and named the regions after these shapes aries
00:14:23taurus
00:14:25and gemini
00:14:26among others
00:14:27but as astrologers gazed at starry skies to divine their fate they also watched and learned how the heavens moved
00:14:39from superstitious motives came the baby steps of scientific observation
00:14:44i see science as a journey that our species has been on for roughly 2500 years to try to
00:14:55come to grips in as deep a way as possible with the universe the laws of the universe the structure of
00:15:01the universe what makes things up how do they evolve and what are the forces that govern change
00:15:08but sometimes simple observations can lead to fundamentally wrong conclusions
00:15:17when we look out at the universe the first sense you get is that we're the center of the universe
00:15:20that the universe is revolving around us
00:15:22the stars go across the night sky the sun goes across during the day and the sense was that the
00:15:29earth was fixed and that the heavens rotated about us
00:15:33but that perception is completely wrong earth isn't fixed it's not the center of anything
00:15:41the whole history of cosmology is the relentless retreat of earth from center stage
00:15:47of the earth's knowledge nevertheless the gathering of knowledge moved forward
00:15:55using mathematics the ancient greeks provided more detailed information about our dominant
00:16:01celestial neighbors the sun and moon even back then 2000 years ago they knew that the earth curves
00:16:10and by looking at the shadows they calculated the size of the earth to within about 10 percent accuracy
00:16:17they actually calculated the distance from the earth to the moon and the rough dimensions of the distance
00:16:23from the earth to the sun so in other words the ancients were no fools
00:16:30the ancient greeks also recognized two types of stars most were fixed and small and moved together
00:16:38a few were larger and moved haphazardly or so it seemed these were planets and predicting their motion became a
00:16:51centuries-long goal
00:16:55with just their naked eyes to scan the skies the greeks saw only five planets naming each after their gods
00:17:03the planets
00:17:07today we're more familiar with their roman designations
00:17:11mercury
00:17:12venus
00:17:14mars
00:17:16saturn
00:17:18jupiter
00:17:20ancient astronomy assumed a concept of the universe
00:17:24proposed by fourth century bc greek philosopher
00:17:27Aristotle, who imagined the Earth at the center of the universe, with the sun, moon, stars
00:17:38and planets all revolving elegantly around it in perfect crystalline spheres.
00:17:46Aristotle's universe was finite. It was a big sphere. Actually, it was like onion.
00:17:51It was an onion with many concentric spheres.
00:17:54First-century astronomer Ptolemy improved on Aristotle by accurately tracing the paths of the planets,
00:18:04which didn't move haphazardly after all.
00:18:08Using complex circular motions called epicycles, Ptolemy could predict their prescribed paths and changing velocities.
00:18:18In other words, Ptolemy's system reliably predicted the future behavior of the planets.
00:18:25Another step in man's journey to understand and control the universe.
00:18:31The Ptolemaic system was extremely complex. It had all these planets going in loops, and it worked beautifully, but it was just wrong.
00:18:40The idea that you can predict something doesn't mean you understand the fundamental principles behind it.
00:18:47Ptolemy's system did not accurately reveal the universe, but it didn't try.
00:18:55He essentially showed that the positions of the planets could be calculated for any time past or future.
00:19:06It was a tour de force of mathematical understanding.
00:19:11Interestingly, the astronomy seemed to stand still for centuries after that.
00:19:19In fact, after the collapse of Rome in 476 AD, astronomy actually lost ground.
00:19:28Europe fragmented into smaller powers, and a lot of the wisdom of the Greeks was lost.
00:19:35A thousand years later, a new theory would confront accepted beliefs about how the heavens worked,
00:19:44and would move mankind one step closer to a theory of the Big Bang.
00:19:52During the 15th century AD, an idea called heliocentrism claimed the sun, not the earth, was at the center of the universe.
00:20:04This horrified Christian clergy, who felt it contradicted the word of God.
00:20:10If God created earth, and man in his own image, then earth, and its devout inhabitants, must be the center of everything.
00:20:22Ironically, the champion of a sun-centered universe was a devout church deacon from Fromburg, Poland, named Nicholas Copernicus.
00:20:33He was a cathedral administrator, working to help collect the rents, helping people who were sick.
00:20:42But, in between, he was working on astronomy.
00:20:45Copernicus was troubled by Ptolemy's complex heavenly mechanics.
00:20:51But, he found an elegant solution, when he moved the earth from the center of the solar system,
00:21:00and replaced it with the sun at the heart of it all.
00:21:10When Copernicus put the planets going around the sun, he discovered that the planet Mercury, which goes around in about three months, automatically fell closest to the sun.
00:21:31And, Saturn, the slowest planet, which goes around in about thirty years, automatically fell at the outside edge.
00:21:40Copernicus wrote, in no other way do we find such a sure harmonious connection between the size of the orbit and its period.
00:21:50That seemed almost magical.
00:21:58Copernicus also insisted that the earth was rotating, that it spun completely around on an axis every twenty-four hours.
00:22:09The heavens didn't move. We did.
00:22:14Stars chasing across the sky each night were merely an illusion created by the rotating earth.
00:22:25Likely afraid of church reprisals, Copernicus withheld publishing his theory until he was on his deathbed in 1543.
00:22:36But his book, Concerning the Revolutions of the Celestial Orbs, paved the way for Johannes Kepler, born in 1571, the champion of observational science.
00:22:51Kepler was the real hero here, because he was the one that really came out and trumpeted to the world that the sun has to be the center.
00:23:03Kepler had at his disposal a trove of astronomical data collected through years of staring at the sky.
00:23:14When he chugged through his observations and did the calculations, realized that not only was the sun center of the solar system, but the perfect circles were a figment also.
00:23:28It was uglier philosophically, but it really matched the data.
00:23:33Kepler improved on the Copernican system by hypothesizing that the planets traveled not in perfect circles, but in ellipses around the sun.
00:23:49Kepler's data also pointed to a strange phenomenon he struggled but failed to understand.
00:23:58As planets approach the sun, they speed up.
00:24:02Further away, they slow down.
00:24:07Together, the sun centered universe and the variable speed of the planets best explain what we see here on Earth.
00:24:22Suddenly, and for the first time, the sun centered picture gives better predictions than the Earth centered picture.
00:24:33And then you have not only something that's driven by data, but does what science is supposed to do, which is to make predictions which are good.
00:24:40But as one cosmic riddle appeared solved, another remained.
00:24:47Kepler saw that the sun influenced the speed of the planets as they traveled through space.
00:24:53But how?
00:24:55Before anyone addressed this mystery, dogma and science collided in a conflict that reverberates to this very day.
00:25:05At the turn of the 17th century, Italian astronomer Galileo Galilei would take the theories of Copernicus and Kepler,
00:25:20that the sun was at the center of the solar system, and prove them right beyond any shadow of a doubt.
00:25:28He did this with a new technology that would change the course of history.
00:25:35The telescope, in some sense, is the most blasphemous, the most seditious, the most revolutionary, and the most splendorous instrument of science.
00:25:47All of science received the greatest of gifts in this tool that brought distant objects close.
00:25:57Once the idea got out that you could take two lenses, line them up in such a way, put them in a tube, and make a spyglass out of it,
00:26:09that would spread like wildfire around the world, as it did.
00:26:14And so the issue now is not who's got the telescope, but do you now know what to do with it?
00:26:21Are you looking in people's windows, or are you looking up and out into the universe?
00:26:28Galileo improved on the design in 1609 by grinding his own lenses and creating one that could magnify an unprecedented 30 times.
00:26:46And with that telescope, for some reason, he decided to look at the sky as opposed to the incoming ships to the Republic of Venice,
00:26:58and what he saw completely changed the scope of astronomy.
00:27:02Galileo was treated to the clearest, most detailed view of the heavens any person had ever known.
00:27:10Through his telescope, Galileo saw thousands more stars.
00:27:16A moon pocked with craters, satellites circling Jupiter, Saturn with giant ears.
00:27:26Greatest of all, Galileo plainly saw that Venus went through phases like our moon.
00:27:34Clear evidence that Venus orbits the sun.
00:27:40Proof of a sun-centered solar system.
00:27:45It showed for the first time that Copernicus was really right.
00:27:49The Earth wasn't the center of the solar system, the sun was.
00:27:53So Galileo, with his telescope, pushed the Earth away from the center of the universe and said,
00:27:59we're not the center of everything.
00:28:02We're one planet among others.
00:28:06And there could be a much larger universe than we know.
00:28:11What Copernicus had assumed for aesthetic reasons,
00:28:14what Kepler deduced through measurements and mathematics,
00:28:18Galileo proved.
00:28:21Galileo saw.
00:28:24Galileo revealed.
00:28:27The ancients had seen everything that could be possibly seen to the naked eye.
00:28:33It really took a new instrument to get beyond that.
00:28:38The telescope, that was where the breaking point was between the ancients and the moderns.
00:28:44Centuries of church dogma claiming Earth was the center of the universe was now plainly wrong.
00:28:51With the Catholic Church still reeling from the schism of the Protestant Reformation,
00:28:57Galileo's discovery appeared to undermine scripture.
00:29:02Dangerous for a church that felt under siege.
00:29:06Dangerous for a scientist proposing it.
00:29:10Nevertheless, Galileo, a devout Catholic, published his observations in a book called The Starry Messenger in 1610.
00:29:21Surprisingly, the church welcomed Galileo's findings at first.
00:29:27Had Galileo been a little more careful in his approach, he might have gotten away with it.
00:29:34One famous quotation from Cardinal Baronius, a predecessor, was,
00:29:40The Bible tells us how to go to heaven, not how the heavens go.
00:29:44Ultimately, Galileo's downfall was not his inability to sway the church to his way of thinking,
00:29:52but rather his attempt at interpreting scripture all by himself, independent of the church.
00:30:00Galileo quotes the famous Saint Augustine, who said that if you found an interpretation of scripture
00:30:07which seemed to be contradicted by well-established knowledge,
00:30:10then you should reconsider that interpretation of scripture.
00:30:13But the church, concerned with perceived threats to its own power,
00:30:18could not concede biblical interpretation to Galileo.
00:30:26In 1633, after Galileo published a new book championing the sun-centered system,
00:30:33the pope summoned him to stand trial for heresy.
00:30:37He's forced to give up all his Copernican ideas, which apparently he did kneeling in front of the tribunal.
00:30:47Despite his concession, Galileo quietly held fast to his beliefs throughout his final years under house arrest at his villa outside Florence.
00:31:02Galileo is the first modern scientist, in the sense that he actively engaged in observations with the telescope,
00:31:14he actively proposed theories consistent with the telescope, and he dared, he dared to challenge the orthodoxy of the moment.
00:31:21Shortly before his death in 1642, Galileo inadvertently stumbled over a clue to Kepler's puzzle about the sun's strange influence on planetary motion.
00:31:36It was a clue that would help point future generations toward a theory of the Big Bang.
00:31:43Galileo's last published work dealt with the properties of falling bodies,
00:31:49which he noted, always accelerated at the same rate, no matter what their mass.
00:31:56But it would take another genius to connect these two puzzle pieces together in a theory of gravity.
00:32:05Isaac Newton, born in 1643, explained the mechanism by which the planets moved.
00:32:16And not just how planets moved, but how everything moved, from planets to apples.
00:32:26Newton was a towering intellect. It is astonishing what he did.
00:32:43His moment in the history of science is a sharp break in which the power of mathematics is really brought to bear on aspects of the physical universe.
00:32:54He is what set us down this path of using mathematics to describe the universe,
00:32:59showing that math, for some reason, is the language of the cosmos.
00:33:06Kepler observed through his data the attractive effects of the sun.
00:33:11It acted like a giant magnet.
00:33:16Might the planets also be like magnets?
00:33:20Galileo had theorized about the rate of acceleration of falling bodies.
00:33:25And he realized that regardless of their mass, falling objects always fall at the same rate.
00:33:32But years later, Newton had something to add to Kepler and Galileo.
00:33:38The great insight Newton had was to bring Galileo and Kepler together,
00:33:43and to realize that the things that make projectiles move and fall on Earth
00:33:47is the same thing that makes the planets go around the sun in the skies.
00:33:53In a sense, the planets are falling toward the sun,
00:33:57just as Galileo's falling bodies fell toward the Earth.
00:34:06The crux of it all is gravity,
00:34:09the strange action at a distance that holds everything together.
00:34:16Newton didn't just observe gravity.
00:34:18He drew it up as a provable equation,
00:34:22showing that gravity was the energy,
00:34:25the tether,
00:34:27that kept matter,
00:34:28objects like the Earth and the planets,
00:34:31from flying headlong into interstellar space.
00:34:36Gravity,
00:34:37the attractive force that affects all matter in the universe,
00:34:41gives the universe order,
00:34:43and gravity is described by the science of physics.
00:34:52Newton created physics.
00:34:55He was the person who first saw the fundamental laws
00:34:58underneath all of these observations.
00:35:01Newton's laws explained almost everything.
00:35:07Newton postulated the laws of motion,
00:35:09the universal rules of gravity.
00:35:14He begins a new era in science,
00:35:17using observations and mathematics
00:35:19to describe the laws of nature.
00:35:24He could, in fact, show that the rate at which an apple
00:35:26was falling to the Earth
00:35:27was directly related to the way the moon was falling around the Earth.
00:35:31Because he understood that the same laws
00:35:33that led to the motion of the planets around the sun
00:35:36led to the motion of the moon around the Earth.
00:35:38Newton's great book,
00:35:43The Principia,
00:35:45revealed that the tides,
00:35:48the velocity of orbiting planets,
00:35:51even the shape of the Earth
00:35:54could be explained through the pull of gravity.
00:35:57Because everything with mass
00:35:59exerts a pulling force on everything else with mass.
00:36:03The moon pulls the oceans.
00:36:08The Earth pulls the moon.
00:36:12The sun pulls the Earth.
00:36:15And the closer these objects are to each other,
00:36:18the stronger gravity pulls.
00:36:20Newton's Principia is such an engulfing work of genius
00:36:24that it almost makes up for one disconcerting fact.
00:36:29Although Newton formulated the laws that govern gravity,
00:36:33he never explained or even understood why it works.
00:36:37And gravity, when you think about it, is bizarre.
00:36:40Understanding how the Earth knew where the sun was,
00:36:44to go around it.
00:36:45What happened if the sun suddenly moved?
00:36:46What would the Earth do?
00:36:48This action at a distance is something which he gave up on.
00:36:50He said, I'm just not going to worry about that question.
00:36:53Because the laws work.
00:36:54Although physicists still struggle to define gravity,
00:37:00Newton had gone far in revealing it.
00:37:04Two hundred years later,
00:37:06Albert Einstein would rival Newton's genius.
00:37:10Not only creating new laws of physics,
00:37:13but reinventing the universe.
00:37:15Albert Einstein, born in Germany in 1879.
00:37:24Maybe the most famous scientist who ever lived
00:37:28because of what he did here in Bern, Switzerland in 1905.
00:37:34Failing to secure a teaching position after his years as a student,
00:37:39Einstein took a job at this patent office.
00:37:42And then he began to think.
00:37:46In fact, he thought up a revolution in space and time.
00:37:54Without Einstein,
00:37:56we might still be struggling to understand
00:37:59how the universe really works.
00:38:03I think if we were asked
00:38:05who was the greatest scientist of the 20th century,
00:38:07most of us would say Einstein.
00:38:09And I think it's partly because of the fact
00:38:11that there's a natural fascination with space and time,
00:38:15the mysteries thereof.
00:38:17But also I think it is partly because
00:38:19he fitted the archetype public perception of a scientist.
00:38:25Einstein didn't mean to lead us to the origin of the universe.
00:38:29He didn't even like thinking about it.
00:38:32The idea of a beginning suggested a dynamic, finite universe.
00:38:36finite universe.
00:38:38And Einstein preferred a static, infinite one.
00:38:42Philosophically, he believed that the universe was eternal
00:38:46and that a universe that had to have a beginning or an ending
00:38:50was unesthetic, it was not pretty.
00:38:52The idea that the universe was infinite and eternal was an old one,
00:38:59embraced by scientists like Einstein because it was easier to think of the universe as always existing,
00:39:07rather than as having been created.
00:39:10Created how? By what?
00:39:11Unfortunately for Einstein, his new understanding of forces like gravity would ultimately suggest the universe was not eternal.
00:39:25Einstein's ideas were so bizarre,
00:39:28it's almost easier to think of them as applying to some other crazy carnival world.
00:39:44But strange as it may seem, our world is Einstein's world.
00:39:50Gather round, gather round, don't push, don't shove, make sure you get a good view.
00:39:54The show is about to start, you don't want to miss a thing.
00:39:58Hurry, hurry, hurry, ladies and gentlemen, step right up to Einstein world,
00:40:03where things are always what they appear to be, but not always what you'd expect.
00:40:08First up, the wondrous Einstein himself.
00:40:12Born missing a region of the brain that influences speech, he did not speak until the age of three.
00:40:17However, his parietal lobe, responsible for mathematical thought and spatial relationships, grew larger,
00:40:24making his entire brain 15% wider.
00:40:29Notice the enlarged brain.
00:40:32Einstein was the master of what we call the thought experiment.
00:40:36Thinking through an experiment that you can't literally carry out,
00:40:39but based upon your insights from thinking about it,
00:40:43sometimes resulting in a revolution in how we think about the universe.
00:40:48In 1905, Einstein published his theory of special relativity,
00:40:54which explored the link between space and time.
00:40:58In Einstein's view, there isn't really a separate thing.
00:41:02There's space and then there's time.
00:41:03But there's just one thing, space-time, that we all live in.
00:41:09He thought of this new space-time as a fabric weaving together space and time.
00:41:16In 1915, Einstein developed his theory of general relativity,
00:41:22which modified special relativity to include gravity and its effects on this fabric of space-time.
00:41:29Welcome to the bouncy trampoline of gravity.
00:41:36We've taken our fabric of space-time,
00:41:40stretched it taut,
00:41:43and placed a heavy weight on it.
00:41:46See how it warps the fabric of space-time.
00:41:51When we roll the ball across the fabric,
00:42:12it magically seems to be drawn, or attracted,
00:42:16to the massive weight at the center.
00:42:18The general theory of relativity was a new theory of gravity,
00:42:23one that told us that gravity worked because space and time were curved in the presence of matter,
00:42:32and could respond dynamically.
00:42:34Space itself could expand and contract in the presence of matter.
00:42:37A crazy but true idea.
00:42:40Mass is a term used to describe the energy and matter that objects contain.
00:42:45The larger the mass of an object,
00:42:49the greater its distortion of the space-time fabric,
00:42:53the stronger the effects of gravity.
00:42:56Gravity is not really a force.
00:43:01It's a fabric.
00:43:03It's a shape of space and time.
00:43:08And we just move along the curves of these shapes.
00:43:14And the act of doing so takes what would otherwise be a straight line to you,
00:43:20and bends it into what you now describe as orbits, as trajectories, as pathways through the cosmos.
00:43:26Einstein said not even light can escape the effects of gravity.
00:43:34As crazy as this sounds, proof conveniently arrived in 1919,
00:43:41in the form of an astronomically large experiment based on a solar eclipse.
00:43:48General relativity said that if you look at a star on a path of light that goes right past the sun,
00:43:57you would see it shift just a little bit because of the gravity of the sun.
00:44:02So Arthur Eddington actually went out to test that theory during the solar eclipse of 1919,
00:44:09and actually photographed stars when the sun was blocked by the moon,
00:44:14and you could see the stars behind it.
00:44:18The ability to see objects that were actually behind the sun proved that objects could warp space-time.
00:44:28Einstein became a superstar overnight.
00:44:32He received the Nobel Prize in Physics in 1921.
00:44:37But general relativity opened a Pandora's box for Einstein.
00:44:41One of the consequences of Einstein's theory was that the universe must either be expanding,
00:44:50or it must be contracting.
00:44:52But sitting still, being eternal, is not a valid solution.
00:44:58And that was a problem.
00:45:02A problem, because if you introduce mass into Einstein's static universe,
00:45:07all that mass will, through gravity, draw together.
00:45:14What was preventing this from happening?
00:45:18When you put matter in a spherical universe, you know, matter attracts each other,
00:45:25and the thing is unstable.
00:45:27To keep gravity from collapsing the universe,
00:45:30Einstein postulated a force equal to and opposite gravity.
00:45:37This constant force perfectly countered gravity to achieve a static universe.
00:45:45Einstein searched for this cosmological constant,
00:45:49convinced it was hiding in his equations.
00:45:52But he was wrong.
00:45:54If Einstein had had the courage of his convictions, in some sense,
00:45:59he would have recognized that the static universe he believed in
00:46:03was not compatible with the theory that he'd come up with.
00:46:09In fact, relativity pointed to the idea that the universe wasn't static,
00:46:14but expanding.
00:46:20Sit right down, folks, and enjoy the magic space-time projector.
00:46:27Watch the universe, linked by four dimensions, move forward in space-time.
00:46:37Einstein himself didn't want to make that prediction
00:46:40that his own theory was sort of screaming to make.
00:46:43It was, I suppose, the one time in Einstein's career where his courage failed him,
00:46:48and he didn't make the bold prediction that was actually staring him in the face.
00:46:55Einstein's theory inevitably leads to the idea of a moment of creation.
00:47:05Now brace yourself for the part that Einstein couldn't watch.
00:47:08Stand back, everyone, as we run the projector backwards.
00:47:17Despite what Einstein believed,
00:47:20his theory pointed to a dynamic universe
00:47:24that was once much smaller.
00:47:29The universe shrinks down to the size of an atom.
00:47:33Einstein couldn't make that leap, but others would.
00:47:39A dynamic and expanding universe fit nicely into a theory called the Big Bang.
00:47:48At the dawn of the 20th century,
00:47:53Albert Einstein may have inadvertently led us to consider the scientific possibility
00:47:57the scientific possibility that our universe began.
00:48:03But the idea of a beginning for everything has strong religious overtones.
00:48:08The culture will ask itself, where did I come from?
00:48:12It's a very important question for humans.
00:48:16Because if we don't know where we came from, we don't know who we are.
00:48:21For thousands of years, the origin of our world was a matter for religious scholars, not scientists.
00:48:28There is a difference between science and religion.
00:48:32They are looking at the world in different ways.
00:48:35They are asking different questions.
00:48:37Science essentially asks how things happen, what's the process of the world.
00:48:40Religion is asking what I think is a deeper and more interesting question.
00:48:43Why are things happening? Is there something going on?
00:48:46Some meaning and purpose in the world?
00:48:47Religion and science have been uneasy companions.
00:48:53If only because they seem motivated by the same quest for truth.
00:48:59So it was ironic that an early champion of an objective scientific theory for the origin of the universe was an ordained Catholic priest.
00:49:11And what a strange twist that his science-based solution would appear so religious.
00:49:22That the universe didn't always exist.
00:49:28But that there was once and in the beginning.
00:49:32Father George Lemaitre argued that the universe was born.
00:49:37Father George Lemaitre is one of my ideals.
00:49:43For a few years, from the late 20s to the early 30s,
00:49:47he was the one who best understood the concept of an expanding universe
00:49:53and introduced many of the ideas we're still exploring.
00:49:56Lemaitre studied Einstein's theories during the 1920s and proposed a radical idea,
00:50:03one that even the great Einstein would reject.
00:50:08He said the universe wasn't static, but was actually expanding.
00:50:17Lemaitre studied Einstein's equations kind of without prejudice.
00:50:22And when he found that these equations suggested a universe that would be expanding today
00:50:27and therefore ever smaller in the past, he decided to take that solution seriously.
00:50:35If the universe was expanding, Lemaitre reasoned,
00:50:40it was smaller yesterday than it is today.
00:50:43Therefore, it must have been ultimately unimaginably small.
00:50:48Lemaitre believed the universe began with what he dubbed a primeval atom,
00:51:03an infinitely dense, hot, cosmic egg that at some time in the past exploded,
00:51:11setting the universe into motion and leading to the formation of everything we know.
00:51:20When Lemaitre told Einstein about this solution,
00:51:26Einstein reportedly said your mathematics is correct, but your physics is abominable.
00:51:31But this abomination soon received compelling corroboration in 1925.
00:51:44In the mountains above Los Angeles,
00:51:47astronomer Edwin Hubble saw something in his telescope
00:51:51that destroyed Einstein's cosmological constant
00:51:54and altered our image of the universe.
00:51:56In the 1920s, we had this very comfortable picture of the universe.
00:52:02The universe is the Milky Way galaxy.
00:52:05You see this huge swath of milk that cuts across the night sky called the Milky Way,
00:52:11consisting of about a hundred billion stars.
00:52:14It was about a hundred thousand light years across.
00:52:17That was the universe in the 1920s, very comfortable.
00:52:20Hubble peered deeper into the universe than Galileo could have imagined,
00:52:27using the most sophisticated telescope of his day.
00:52:31He revealed our sun as one star among billions within the Milky Way galaxy.
00:52:38But was the Milky Way all there is?
00:52:44If so, exactly how big was it?
00:52:48Since the advent of powerful telescopes,
00:52:52astronomers had been looking in the skies,
00:52:55but they had no good measure of how far away things were,
00:52:58except for very close stars.
00:53:01Edwin Hubble solved that problem by coming up with what's called a standard candle,
00:53:05a star of known brightness.
00:53:09And if you know how bright it is,
00:53:12you can measure how far away it is,
00:53:15because the dimmer something appears, the further away it is.
00:53:18Just like a train in the distance, the light seems dim,
00:53:22and it gets brighter and brighter and brighter as it approaches you.
00:53:25Hubble found one of these standard candles
00:53:28within a spiral swirl of stars called the Andromeda Nebula.
00:53:32People thought Andromeda was just a wisp of stardust inside the Milky Way.
00:53:39Then Hubble calculated the distance,
00:53:43and then he realized that galaxy is a million light years away.
00:53:48That was the Eureka moment.
00:53:51And he had this epiphany.
00:53:54He realized that the Andromeda galaxy was an island universe,
00:53:58just like the Milky Way galaxy.
00:54:02So in one instant,
00:54:04the universe went from being a comfortable Milky Way galaxy
00:54:08a hundred thousand light years across,
00:54:10to becoming this fantastic universe,
00:54:13perhaps billions of light years across.
00:54:16And it all happened in just one night.
00:54:18This alone would have ensured Hubble's immortality.
00:54:24He single-handedly grew the universe from a quaint one-galaxy town,
00:54:30to a potentially billion-galaxy metropolis.
00:54:34But Hubble went one further.
00:54:37He also measured the behavior of those galaxies.
00:54:40And in 1929, he came to the conclusion that most galaxies are moving away from us.
00:54:47Not just that there are lots of them,
00:54:49but they are actually moving away from the Milky Way,
00:54:52and in fact they are moving away from each other.
00:54:55In other words, the universe is expanding,
00:54:59getting bigger every second.
00:55:01And if you went back in time, the universe must have been smaller.
00:55:10Based on the speed of expansion that Hubble measured,
00:55:14he could calculate the age of the universe.
00:55:20Hubble actually came up with an estimate for that, using his data,
00:55:23and he said the universe is about two billion years old.
00:55:27That was bad, because they already knew that the Earth was older than that.
00:55:32Hubble was on the right track.
00:55:34His formula for determining the age of the universe was correct,
00:55:39but his measurements were inaccurate.
00:55:42And this discrepancy gave some scientists room to quibble with Lemaitre's theory.
00:55:50But other, less scientific reasons,
00:55:54also may have contributed to Lemaitre's superatom,
00:55:57being estranged from the physics community throughout the first half of the 20th century.
00:56:03I think there was some resistance to having somebody in the scientific camp and in the religious camp,
00:56:11but did that make it difficult for some scientists to perhaps embrace him as much as they would someone who was not in that position?
00:56:19Probably.
00:56:21Lemaitre's proposal may have left him estranged from his fellow scientists,
00:56:24but it appealed to Pope Pius XII, who interpreted the theory as a defacto proof of the biblical story of Genesis.
00:56:35Lemaitre wrote to the Pope and said,
00:56:36stop saying that.
00:56:37This is a scientific theory that makes a prediction that you can measure, makes many predictions you can test.
00:56:43But your beliefs are independent of those predictions.
00:56:46Lemaitre's theory could be measured, but proved?
00:56:49It seemed unlikely, billions of years after the fact, that the Big Bang's smoking gun would turn up.
00:57:01And unless this smoking gun was found, other theories of the universe could be proposed,
00:57:07and Lemaitre's cosmic egg would remain unhatched.
00:57:11By the middle of the 20th century, it seemed as if the primeval atom theory,
00:57:20with the universe expanding violently outward from an infinitely small speck,
00:57:24would never gain wide acceptance.
00:57:27Hubble's incorrect estimate for the age of the universe allowed a competing theory
00:57:33to emerge from the halls of Trinity College, Cambridge.
00:57:37There was a tenable alternative to the Big Bang theory, namely the steady-state theory,
00:57:45which allowed the universe to exist from everlasting to everlasting.
00:57:51The steady-state theory championed the static universe that the primeval atom concept rejected.
00:57:59Proposed by astronomer Fred Hoyle, it was built upon a theory of the origin of elements,
00:58:05nitrogen, carbon, and more than 100 others in the periodic table.
00:58:11Under extreme temperatures, hydrogen fuses to form helium,
00:58:16and helium fuses into entirely different, heavier elements.
00:58:22Fred Hoyle believed this nucleosynthesis, the creation of new elements,
00:58:27took place in the cores of very hot stars.
00:58:31That was an absolutely staggering achievement at the time.
00:58:37Hoyle's achievement was to teach us that everything after helium,
00:58:43in the periodic table, is actually star dust.
00:58:47It is in the stars that these things were made.
00:58:50But the theory couldn't account for the formation of hydrogen,
00:58:53and most of the helium in the universe,
00:58:57because the first stars must have been made of hydrogen already in existence.
00:59:03This existing hydrogen makes up more than 74% of the detectable universe.
00:59:10Hoyle sidestepped this problem by adopting a widely held belief that hydrogen and helium had always existed.
00:59:20In fact, according to Hoyle, the entire universe had always existed.
00:59:26No beginning, and no end.
00:59:29Just a steady state.
00:59:30In a nutshell, a steady state universe is a universe that's always been here,
00:59:40always looks like it does now, always has the same average density, has the same temperature.
00:59:46There was just a little problem, though, which was people knew the universe was already expanding.
00:59:52When a distribution of matter expands, it becomes more dilute.
00:59:56Now, if the universe is very old, it would be infinitely dilute.
01:00:01Hoyle fixed this flaw by assuming that somewhere,
01:00:06matter was always being created in the universe.
01:00:10But the wholesale creation of matter was a hard pill for physicists to swallow.
01:00:17And Hoyle had a nemesis of sorts in the Russian physicist George Gamov,
01:00:24an admirer of Lemaître's primeval atom.
01:00:29Gamov was usually present in these discussions.
01:00:33And he always brought up nasty questions for Hoyle to consider.
01:00:39Questions that the study said had difficulty dealing with.
01:00:44Gamov turned to atoms, as Hoyle did, to support his competing theory.
01:00:51Gamov suggested that hydrogen and helium and the other elements were created in the first fiery minutes of the universe,
01:01:01in a big bang, when temperatures were thousands of degrees hotter than they are in the core of any star.
01:01:08But Gamov was a better idea man than he was a mathematician.
01:01:15And he had to turn to this phenomenally talented graduate student of his, Ralph Alpher,
01:01:21and it was really Alpher who was able to push this idea through and come to a conclusion,
01:01:28that if indeed the universe synthesized the early elements,
01:01:32there should be roughly ten times as much hydrogen as helium.
01:01:35And that matched the observations.
01:01:37Fantastic moment.
01:01:38Alpher, with colleague Robert Herman, refined Lemaître's prediction of detectable remnant heat from creation.
01:01:48A strong clue supporting the big bang.
01:01:52George Gamow and his students asked a very simple question.
01:01:56If the big bang was so hot then, then the aftershock, the afterglow, the echo of the big bang, can't be so cool now.
01:02:05So the residue should be measurable today.
01:02:12Unfortunately, no one had the right telescopes in 1949 to measure the radiation, or heat, left over from the moment of creation.
01:02:22And at the time, there were other problems with the big bang theory.
01:02:27It offered no explanation as to the origin of the elements beyond hydrogen and helium.
01:02:32At the same time, steady state garnered widespread media coverage.
01:02:40The steady state theory was popular with the general public,
01:02:44because Fred Hoyle was a master of popularization and just going out and marketing his wacky idea.
01:02:50Ironically, the term Big Bang was coined by Hoyle in 1949 during one of his popular radio broadcasts.
01:03:01He later used it as a term of derision.
01:03:06I think there was a dislike in their relationship.
01:03:11They didn't see eye to eye on most of the things they were thinking about.
01:03:18So I think Hoyle came off the worst in battles.
01:03:22I think he did more fighting for his views than was merited, but that's a personal opinion.
01:03:32Fred was a very, very brilliant and innovative sort of person.
01:03:35Ideas just poured out of him.
01:03:37Some of them were good and some of them were bad, and he didn't always know which was which.
01:03:40By the 1960s, Hubble's inaccurate estimate for the age of the universe had been corrected to reflect more accurate data,
01:03:51resolving one challenge to the Big Bang theory.
01:03:57Still, it seemed the battle between the steady state and the Big Bang would end in a draw.
01:04:03But then, all of a sudden, scientists found a smoking gun.
01:04:12One nearly as old as the universe itself.
01:04:19Its discovery doomed one of these theories to the dustbin of history.
01:04:26For 500 years, science has been on a quest to discover where we belong.
01:04:34Now, astronomers struggled to solve the riddle of how it all began.
01:04:42Little did they know, the cosmos was whispering an answer back.
01:04:49We just couldn't hear it.
01:04:54That whisper took the form of leftover heat generated when the universe exploded into being.
01:05:00The radiation that George Lemaître predicted was out there, but that he had no tools to hear.
01:05:08By 1965, scientists had those tools.
01:05:13The residue, the echo, the aftershocks of the Big Bang should be measurable today.
01:05:22But it took about two decades before our instruments became powerful enough to clinch George Gamow and his students' theory of this background radiation.
01:05:33The story of this radiation is like the Keystone Cops.
01:05:39First, we had George Gamow and his students.
01:05:42They had the theory, they had the numbers, but they didn't have the experimental apparatus.
01:05:46Then we had the group at Princeton.
01:05:49Well, they knew the work of George Gamow, but they had a very primitive instrument, not sensitive enough.
01:05:56The group at Princeton included physicist Robert Dickey and some colleagues who supported Lemaître's theory and wanted to look for some solid proof.
01:06:06My teacher, Bob Dickey, he had the idea of looking for this radiation that would be left over from a hot Big Bang.
01:06:17He had two bright young people working with him, Dave Wilkinson and Peter Roll.
01:06:23He persuaded them to build a Dickey radiometer to look for this radiation.
01:06:28It was a shot in the dark.
01:06:29So his two young colleagues built one, pointed it into the air, and started looking when news of their experiment reached Bob Wilson and Arno Penzias.
01:06:44Penzias and Wilson were two scientists working not on the Big Bang theory, but on satellite communications for Bell Labs in Holmdel, New Jersey.
01:06:54They were using Bell's huge radio telescope, only they couldn't get a clean reading.
01:07:01Instead, they got static noise.
01:07:07The nature of this stuff is that it's random noise.
01:07:11And that noise is very much like what you would hear if you tune a TV set or an FM receiver to an unused channel.
01:07:20We didn't see what we expected.
01:07:22The antenna was actually getting more radiation than it should have.
01:07:28Our clear response to that was, there must be something wrong here, that we're getting all this extra noise.
01:07:35What was this strange noise?
01:07:38And where was it coming from?
01:07:41Errant interference from nearby New York City?
01:07:45Airplane signals?
01:07:46Pigeon droppings inside the horn of the telescope?
01:07:51We didn't doubt physics.
01:07:55Whatever it was had to be coming from somewhere.
01:07:58But we were really running out of ideas of where it might be.
01:08:02In fact, this mysterious radiation was coming from everywhere, every direction and every corner of space.
01:08:14To Penzias and Wilson, that was just crazy.
01:08:18But Penzias and Wilson had unknowingly found what Dickey and his colleagues were seeking.
01:08:26What Gamow, Alpher and Lemaître had predicted.
01:08:30They'd found the smoking gun that proved the universe wasn't eternal.
01:08:39The source was the creation of the universe, the Big Bang.
01:08:52Penzias and Wilson and the Princeton team published their findings in separate papers in Astrophysical Journal in 1965.
01:09:01Their research crushed Hoyle's steady-state theory overnight.
01:09:08Finally, the Big Bang fit into the puzzle of the universe.
01:09:13Our modern theory of the Big Bang is a remarkable achievement in it allows us to make a model of what the universe was like,
01:09:22right back to when everything was only a tiny fraction of a second old and was squeezed to immense densities and temperatures.
01:09:29And from that very early dense state, we can understand in broad outline how the universe expanded and cooled,
01:09:38how at some stage the first atoms formed, how at some later stage the first structures formed that made early stars, galaxies and eventually planets and people.
01:09:49In a hospital in Belgium in 1966, the dying George Lemaître rejoiced at the news.
01:09:56He was not alone.
01:10:00Gamow and his team also felt justified.
01:10:05We had been arguing for a different view of the universe.
01:10:09And lo and behold, that different view seemed to be the correct one.
01:10:13So that's always a vindication.
01:10:19For their part in the discovery, Penzias and Wilson won the Nobel Prize in 1978.
01:10:26Though Hoyle's steady-state theory has fallen out of favor, his theory of nucleosynthesis was not rejected.
01:10:35While most scientists agree that hydrogen and most of the helium were created in the first few moments of the Big Bang, as Gamow believed,
01:10:48all other heavier elements like nitrogen and carbon were created later, in the hot centers of stars and in supernova explosions, as Hoyle suggested.
01:11:02So, in essence, both Gamow and Hoyle were correct.
01:11:09Despite this partial vindication of nucleosynthesis, Hoyle, who died in 2001, never accepted the Big Bang.
01:11:20He could not understand why people were so enthusiastic about a universe which had a finite beginning in what I suppose he thought was the recent past, a few billion years.
01:11:32He just never accepted it.
01:11:34But the rest of the physics community, with almost total unanimity, did accept it.
01:11:40The fact that we've discovered it has a beginning allows you to now ask a whole set of questions about how it began.
01:11:49And that's kind of interesting. That's kind of cool.
01:11:52Because you can say, when did it begin? How was it different then than today?
01:11:56What changes unfolded between then and now to create the universe we now know?
01:12:01But accepting the Big Bang theory and thinking it flawless are two different things.
01:12:10There were problems with the details of the theory.
01:12:14Expanding problems.
01:12:21During the latter days of the 20th century, scientists examined problems with the Big Bang,
01:12:27even though the theory was generally accepted.
01:12:31One of the biggest problems was that the temperature in outer space was strangely uniform.
01:12:40Physicists didn't expect that the universe would have the same temperature roughly everywhere they looked.
01:12:50The universe is simply too large for one end of it to be the same temperature as another.
01:12:55Yet it is.
01:12:58It's the same thing that happens if you have a bathtub full of cold water,
01:13:03and you pour in some hot water in one extreme.
01:13:06It's going to be a while before the whole bathtub has tepid water,
01:13:10because it takes time for that hot molecules to propagate across and normalize the whole distribution.
01:13:18The universe doesn't appear to be old enough for its temperature to have equalized yet.
01:13:22The Big Bang could not explain why such far away points have the same temperature.
01:13:33In the early 80s, Alan Guth came up with this idea that perhaps the universe came from a very tiny volume.
01:13:42So tiny that within that volume, early on, there was time enough for these different points to communicate and normalize that temperature.
01:13:52Right after this moment, Guth theorized that the universe expanded even faster than light.
01:13:59Faster than the cosmic speed limit, the ultimate speed, according to Einstein.
01:14:08What inflation refers to is a theory of what propelled the expansion of the Big Bang.
01:14:13Guth called his theory inflation.
01:14:17In the earliest moments of creation, for instance, scientists believe the four forces of nature, including gravity and electromagnetism,
01:14:28were actually combined into a single superforce.
01:14:31During the big bang, this superforce split into the four known forces.
01:14:39But before it split, when the universe was incredibly small,
01:14:45Einstein's laws of physics, including the one that says nothing moves faster than light, didn't apply yet.
01:14:52Maybe at that moment, something happened that caused the universe to expand even faster than light.
01:15:03So fast that it locked in the uniformity it had when the universe was still small.
01:15:10We don't know exactly when inflation happened.
01:15:13Most likely it happened when gravity had split off from the other three forces,
01:15:18but at a time when the other three forces were still very likely unified.
01:15:23This hyperexpansion, if it happened, would lock in a certain uniformity of temperature.
01:15:42On June 3, 2001, NASA launched a satellite that could potentially determine one way or the other
01:15:49the truth about Guth's inflation theory.
01:15:56The Wilkinson Microwave Anisotropy Probe, or WMAP mission, planned to photograph the fossil, remnant heat of the Big Bang that Penzias and Wilson had found.
01:16:08In other words, NASA wanted to take a baby picture of the universe that they could then compare with how the universe looks today.
01:16:20In February 2003, scientists got their first glimpse of WMAP's picture of the baby universe when it was a mere 380,000 years old.
01:16:34The clarity of the data stunned scientists.
01:16:42The reaction people had when they saw this was,
01:16:44Wow!
01:16:46It really was the way people had been speculating earlier on.
01:16:51Inflation probably happened.
01:16:52To the untrained eye, the WMAP image looks like a speckled robin's egg.
01:17:00But to scientists, this was a stellar Rosetta Stone.
01:17:04These patterns represent the seeds that later grew into the vast expanses of stars and galaxies of today.
01:17:17Besides strongly supporting Guth's inflation theory,
01:17:22the data also gave us concrete clues to the age, composition, shape, and evolution of the universe.
01:17:32Up until a few years ago, cosmology was quite distinct from other sciences.
01:17:39Simply because there were more theories running around than data.
01:17:45And it was not until these satellites measured what was going on shortly after the Big Bang with such high precision
01:17:56that you could discriminate one cosmological model from another.
01:18:01And you could produce numerical results about the size of the universe, the age of the universe,
01:18:05the expansion rate of the universe, the contents of the universe.
01:18:09You couldn't do that before these data became available.
01:18:12Before then, it was this mixture of mythology and clever thinking.
01:18:16Thanks to modern tools such as the WMAP satellite, physicists now have a model for the events just after the Big Bang.
01:18:28Less than a billionth of a second after the Big Bang.
01:18:33A bubble much smaller than a fraction of an atom forms.
01:18:40This is the universe.
01:18:44It is unimaginably small and unimaginably hot.
01:18:48Within this bubble, the four known forces of nature, gravity, electromagnetism, plus the strong and the weak nuclear forces,
01:19:03are a combined superforce.
01:19:06Gravity suddenly splits off from the superforce as the universe expands.
01:19:13As the universe expands, it cools,
01:19:17which somehow sets off a burst of energy fueling the hyperinflation of the universe, suggested by Alan Guth.
01:19:26This inflation locks in the uniformity of the universe pictured by the WMAP satellite.
01:19:33The universe is still less than a second old when the superforce decays into the separate forces of nature.
01:19:44Roughly three minutes after the Big Bang,
01:19:48the temperature of the universe has dropped to a mere one billion degrees Fahrenheit.
01:19:54Cool enough for atomic nuclei to form.
01:19:58The element hydrogen forms.
01:20:00Some hydrogen atoms fuse to create helium, as proposed by Gamow and Alpher.
01:20:09Three hundred and eighty thousand years later, and light travels through the darkness.
01:20:19The burst of radiation that Penzias and Wilson found happens now.
01:20:24A billion years after the Big Bang, stars take shape, producing the heavier elements like nitrogen, oxygen and carbon, as Hoyle predicted.
01:20:41Roughly nine billion years out, matter and gravity combine to form a perfectly typical star.
01:20:53Pressure creates heat at its core.
01:20:57This heat triggers thermonuclear fusion.
01:21:01A star is born.
01:21:03Stellar outflow clears away residual gases.
01:21:08A circumstellar disk of dust remains.
01:21:12That eventually accrete into an entourage of planets and moons.
01:21:17One of these lumps of stardust, after being pummeled for eons by residual solar debris,
01:21:25has temperatures warm enough to allow water to build up in the atmosphere.
01:21:31Liquid water gathers on the planet's surface.
01:21:39Underwater, mysterious chemical reactions ultimately form life.
01:21:45Thirteen point seven billion years after the Big Bang, our universe is now 156 billion light years across.
01:21:55The sky is full of stars.
01:21:59Our solar system has eight planets, more or less.
01:22:03The third planet is nearly covered in carbon-based life forms.
01:22:08Some are just realizing what infinitely small specks they are in the grand scheme of things.
01:22:14If you don't understand this process, that's okay.
01:22:21It's the culmination of millions of human brains struggling for thousands of years to figure out how the universe began,
01:22:29and where man fits within it.
01:22:32It's enough to overwhelm any one human brain.
01:22:36If I take seriously the idea that my brain was evolved to be able to throw rocks and pick bananas and stuff,
01:22:41it's pretty remarkable that we humans would be able to figure out much about physics,
01:22:47figure out much about things that didn't have survival value to our ancestors.
01:22:51Yeah, I think it's quite stunning how well we humans have been able to make progress in the industry garden,
01:22:57and not go completely bananas in the process.
01:23:00This is our story of everything. Our world, our solar system, our universe, and how it all began.
01:23:12This is what we think we know.
01:23:16It's a work in progress. The script is still being written.
01:23:21But let's see how it ends.
01:23:24New York City.
01:23:32A beautiful but unremarkable autumn day.
01:23:37Like thousands before it.
01:23:39And thousands to come.
01:23:41Until there aren't any more autumn days.
01:23:44Imagine for a moment traveling into the future for billions of years.
01:23:59Past the end of human civilization and the lives of all living creatures on Earth.
01:24:22Imagine we are five billion years into the future.
01:24:29The sun is running out of the nuclear fuel that gives it fire.
01:24:46As it cools, it expands and reddens.
01:24:53Coming closer and closer to Earth.
01:24:56It swallows up Mercury and Venus.
01:25:01Water on Earth evaporates and Earth becomes molten again.
01:25:07When the fuel is gone, the sun's core ultimately contracts as it transforms from a red giant to a white dwarf.
01:25:24The expanding outer layers of the sun, called a planetary nebula, drift into space as ghostly shrouds of glowing gas.
01:25:35The planets that survive this process, the outer ones like Saturn and Neptune, are utterly changed by it.
01:25:48The planetary nebula blows away their gassy atmospheres, leaving small, rocky and metallic cores behind.
01:25:57The distant planets, no longer held by the less massive sun's gravity, drift into the vastness of space.
01:26:10Travel billions of years after that, and all remaining heat from the sun has radiated out.
01:26:17And its small, dark surface is the same frigid temperature as the rest of space.
01:26:25The sun is now a black dwarf.
01:26:28Now, billions of years later, propelled by a mysterious and only recently discovered dark energy, the universe expands ever faster, flying apart everywhere.
01:26:43On a grand scale, and at a molecular one, expansion overwhelms gravity.
01:26:52Everything rips apart.
01:26:55Not just galaxies, solar systems and stars, but even atoms.
01:27:01Finally, matter itself is torn asunder.
01:27:06This is the big rip, the big rest in peace for our universe.
01:27:12The legacy of dark energy, that stuff we still haven't figured out.
01:27:18Right now, dark energy is mostly a code word for our ignorance, what the substance is.
01:27:23Some people think it's some sort of stuff.
01:27:26Some people think it's a constant that should be in Einstein's equation.
01:27:30Some people think it's just a reflection of the fact that we might have gotten our gravity wrong again.
01:27:38Right now, the big rip theory of the end of the universe leads the pack.
01:27:43But who can say if this will remain our theory, or if some new discovery will challenge it?
01:27:48The stuff we haven't figured out yet.
01:27:54It goes on forever.
01:27:56One more blow to our centrality in the grand scheme of things.
01:28:01But that doesn't mean we don't know anything.
01:28:05Copernicus, Newton, Einstein, even Alpher, Wilson, and Guth.
01:28:13They've given us pieces of an endless puzzle.
01:28:16They've helped tell us how we fit in the picture.
01:28:21Recognize that the very molecules that make up your body, the atoms that construct the molecules,
01:28:28are traceable to the crucibles that were once the centers of high mass stars.
01:28:33That exploded their chemically enriched guts into the galaxy.
01:28:37Enriching pristine gas clouds with the chemistry of life.
01:28:42So that we're all connected to each other biologically, to the Earth chemically, and to the rest of the universe atomically.
01:28:55That's kind of cool.
01:28:59That makes me smile.
01:29:02And I actually feel quite large at the end of that.
01:29:05It's not that we are better than the universe, we're part of the universe.
01:29:09We're in the universe, and the universe is in us.
01:29:13We're not the center of the universe, but we are in it and of it, trying to figure it all out.
01:29:25There's so much we know, and yet so much we still don't know.
01:29:29We hold on tight as our little planet goes hurtling through space, around the sun, around the galaxy, around the universe.
01:29:40Don't forget to look up.
01:29:43There's so much to see, so much to know.
01:29:47Where do we begin?