The Beginning Of Time | Space Documentary HD | Science Documentary

[Music] astronomers have begun one of the most far-reaching efforts ever undertaken to study the universe [Music] they are forging giant new lenses and mirrors while marshaling vast computational power these new technologies are at the center of a historic quest to peer into the deepest recesses of time to find out how the universe set the stage for galaxies and worlds like ours [Music] in an era known as the cosmic dawn [Music] bleep men in tow and colleagues from the University of Illinois are part of a global push to advance the science of cosmology the study of the universe as a whole they are mapping the positions of galaxies across the sky and extending deep into the universe their goal to link the evolution of planets stars and galaxies the universe we see around us with conditions that existed at the dawn of time what forces came together to form the very first generation of stars and galaxies and over time the vast architecture of matter and light we see in our telescopes only a century ago astronomers debated whether the universe is confined to a giant rotating disk of stars dust and gas the Milky Way or whether our galaxy is one of many so-called Island universes [Music] we now know that our galaxy is part of a formation of three major galaxies along with some 51 dwarf galaxies called the local group [Music] the local group is bound by gravity to a much larger formation the Virgo cluster with up to 2,000 galaxies beyond Virgo galaxy clusters are linked to super clusters in a pattern laid out by the first great cosmic mapping project the Sloan Digital Sky Survey beginning in the year 2000 as the Sloane data shows super clusters are connected to each other by streams or filaments of galaxies bounded by immense empty regions to understand how the universe got this way astronomers must identify its basic components of matter and energy [Music] back in the 1930s the astronomer Fritz Zwicky measured the rotation rate of spiral galaxies like the Milky Way he found that the gravity that binds their stars is over 100 times greater than what he expected based on the amount of matter that's visible Wiki called the unseen substance exerting this extra gravitational pull dark matter [Music] you can see its influence on even larger scales without dark matter the gravity of clusters like this is not enough to hold all the galaxies rotating around it in this case dark matter acts as a lens magnifying and distorting the light of galaxies in the deep background and causing them to appear as blue arcs astronomers use the pattern of gravitational lensing to map the distribution of dark matter in the super cluster Abell 1689 shown here as a blue haze on a large scale galaxy structures like these are a measure of how much dark matter there is one of the tools that we have in cosmology to pin down the kind of universe that we live in instead is the growth of the structures these are giant systems with hundreds of thousands of galaxies and these systems this ones are particularly big are very very rare and the number of those you can find as a function of cosmic time you know from here to the past depends it's a it's a very strong prediction or of the universe that we live on this computer model shows the role dark matter has played in shaping the contours of the universe not long after the Big Bang gravity began to amplify slight initial variations in the distribution of dark matter regions of the highest density attracted enough visible matter to form galaxies clusters and the largest super clusters even as astronomers struggle to define what dark matter is they discovered another mysterious and powerful influence on cosmic evolution in the late 1990s two groups of astronomers asked whether there's enough dark matter out there to one-day slow or even halt the expansion of the universe using the Hubble Space Telescope along with ground-based telescopes the team set out to track the rate of cosmic expansion through the entire history of the universe they did this by searching deep space for a particular type of exploding star called a type 1a supernova it often begins with two stars in a closed orbit one of which draws gas from its companion when it gains enough mass it undergoes a runaway nuclear reaction and explodes because type 1a supernovae are all thought to blow up in the same way they have the same intrinsic brightness that makes them ideal for measuring cosmic distances it's like looking at car headlights approaching on a highway the dimmer they appear the farther away they are the astronomers combined distance measurements with another marker how far their light had shifted toward the red part of the light spectrum a greater this redshift the more the universe had expanded since the star exploded some explosions appeared dimmer than the team's expected based on their redshift that meant their light had traveled farther than it should have given a constant rate of expansion [Music] this finding led the two teams to conclude that in the deep past the universe was slowing down but to reach its current size it must have been sped up scientists now believe the universe is dominated not by matter we can see nor by the mysterious gravitational presence dark matter it's something else pervasive and powerful enough to cause space to accelerate outward they call it dark energy one leading idea is that it stems from particles that well up from the vacuum of space [Music] as the universe expands it generates more and more dark energy that has the effect over large distances of counteracting gravity and causing space to expand even faster spread over the vastness of the universe it is the energy equivalent of only five hydrogen atoms per cubic meter and yet scientists find that dark energy accounts for 68% of the entire cosmic matter energy budget with dark matter at 27% an ordinary visible matter less than 5% the twin discoveries of dark matter and dark energy have thrown cosmology into turmoil and potentially into a new age of discovery [Music] astronomers have now launched a full-scale effort to pin down the forces and events that drove cosmic evolution going back to the earliest times already a fleet of space telescopes led by Hubble is scanning the distant universe for light sources across the electromagnetic spectrum the long-awaited James Webb Space Telescope slated for launch in 2018 represents the next generation of great space observatories with a segmented primary mirror that is almost three times larger than that of Hubble the James Webb will capture the trickle of photons from a time nearly 13 billion years ago when the universe lit up with stars and galaxies the next generation of ground telescopes will radically extend our light gathering power the European extremely large telescope now under construction in Chile's Atacama Desert will have a 39 meter mirror that quadruples the light gathering power of the largest telescopes today [Music] while these telescopes extend our vision into the deep universe the American W 1st and European Euclid Space Telescope's will take in large regions of the sky at high resolution these new instruments each slated for launch in the 2020s will be used to survey the deep universe for type 1a supernovae and other markers of cosmic evolution these space observatories will work in conjunction with an ambitious new effort to track the evolution of the cosmos in near real-time a large synoptic survey telescope or LSST is being built in the mountains of Chile it combines data gathering on an unprecedented scale with plans for dedicated fiber optic connections capable of delivering a flood of data to supercomputers a continent away from there it will be processed and made available through advanced internet links to scientists around the world [Music] at its heart the LSST will be outfitted with the largest digital camera ever built that includes the largest lens ever built now undergoing final polish before assembly with a field of view the size of 50 full moons the telescope will observe just over half the sky visible from the earth to a depth of about halfway back to the beginning of time plus st is going to take a new image of the sky in roughly every 47 seconds and so for us to bring the picture of the sky to the world as quickly as possible we are going to release a catalog of how the universe appears to have changed with time within one minute of that shutter closing and so every 47 seconds every night for 10 years we're going to distribute effectively a mini worldwide data release of how the sky looks like it changed with time and on average LSST will image the entire southern sky roughly once every several days astronomers expect the telescope to record a blizzard of transient events from asteroids buzzing through the solar system to black holes flaring up in distant galaxies and stars exploding out on the horizons of space and time the telescope will revolutionize what scientists call time domain astronomy right now there are lots of time domain series going on and worldwide you might get thousands of new alerts per night of things that have changed in the sky but LSST will change that it is so much bigger and sample such a larger volume of space that it will have 10 million new things every night that it looks at the sky that's 10 million every night for 10 years and so suddenly it's a whole different ballgame right the scale is well beyond anything that has ever happened in time to astronomy it opens up space that we've never explored before [Music] to make sense of the deluge of data this project will make extensive use of supercomputer models designed to simulate periods in cosmic history these powerful programs are based on theories of star and galaxy formation the influence of dark matter and dark energy and a host of other parameters scientists will use them to test theories about what drives cosmic evolution by comparing simulation results with data captured by the telescope these datasets are so complex that we really need simulations of cosmic evolution to even understand and analyze the data let alone interpret them the computations really translate our theories of dark energy dark matter cosmic evolution into observables that we can then go out and test with our observations the LSST project will build upon previous large-scale cosmic surveys the Sloan Digital Sky Survey has mapped galaxies up to one-third the distance to our visible horizon [Music] astronomers are now leaving beyond that with a project based on a summit across the canyon from LSST it's called the dark energy survey here at a dedicated four meter telescope Philippe men in tow and colleagues are pioneering new systems and procedures for mining the light of deep space because of the time it takes for the light of distant objects to reach us when these astronomers look deep into the cosmos they are looking back in time we are looking back in time kind of like an archeology is like digging deeper into the ground and at each one of these epochs we are kind of like seeing the the relic the fossils that were left so we cannot follow a galaxy back in time but we can actually take a snapshots of populations at different cosmic times and see how they had been changing since early on until today Telescope captures the light of stars and galaxies across the electromagnetic spectrum from high-energy ultraviolet to low-energy infrared these colors reveal important galaxy characteristics such as the rate of star birth the amount of dust or gas within them their distance from Earth the cameras sensor divides the field of view into 62 high-resolution detectors each one captures countless thousands of celestial objects some bright and well-known others too subtle to see with your eye night after night month after month the exposures pile up across a survey area that covers one-fourth of the southern sky or one eighth of the entire sky as seen from Earth with data from the dark energy survey combined with a much larger LSST survey scientists will create a three-dimensional map of galaxies going back to in the universe was half its current age we only understood that we live in a universe full of galaxies in 1919 30s before that we didn't understand our place in the universe and since then there's been this constant quest to understand why galaxies look the way they look how did they form and how this process had been shaping also you know the planets to stars everything that it's in them because you know galaxies are the building blocks in the universe in recent years advanced telescopes have shown that the universe is filled with galaxies in a wide variety of shapes and sizes [Music] from giant spheres of ancient dying stars to complex twisted shapes often run through with rings of dust [Music] the historic Hubble Deep Field took us back for the first time to the early stages of galaxy formation it found that blurry scraps of stars and gas visible at the dark margins of space are primitive galaxies theory says they will one day merge into larger mature galaxies something that you know astronomy has been trying to answer for decades particularly after the Hubble Space Telescope was in space and we were able to see with amazing precision their morphology in the shapes of the earliest galaxies in the universe we've been trying to answer and try to connect morphology and colors with the evolutionary stage of the galaxies okay you have this kind of galaxy and that kind of galaxy how do they fit together or do they fit together does that galaxy turn into this galaxy or the other way around does this kind of galaxy never become that kind of galaxy because it didn't have the right nurturing or the right environment no if you were an alien coming down with no knowledge of how humans work and you landed in a city and you were just walking around looking at some city blocks you would see all kinds of different people you'd see babies and you see old people and you see you know teenagers and people in their mid-twenties but you wouldn't necessarily have an idea of how all those people fit together do people just arrive at these different stages or do they are they working through some evolutionary process so it's the science that but you understand that you know things are evolving so you have a baby that then grows to a toddler grows a teenager that you know eventually becomes an old person using the Alma telescope array in Chile astronomers caught a glimpse of galaxy evolution in its earliest stages they focused the telescope on the southern constellation of Cetus setting their sights on a seemingly empty region deep within it about 3.5 billion light-years from Earth lies the galaxy cluster Abell to 744 it's known as Pandora's cluster for the tangle of shapes created when at least four smaller galaxy clusters merged together to one side astronomers found a faint ghostly shape that had been magnified by dark matter within the cluster it is a pocket of stars far beyond and much older than the galaxy cluster the stars were being born when the universe was just 600 million years old this animation recreates the ancient star cluster surrounded by gas and punctuated with supernovae over time most star clusters like this would have merged with a galaxy as it turns out a small number have managed to stay intact over the billions of years since they were born finding them within their original Dark Matter cocoons has become a passion for these members of the dark energy survey Alex de Luca Wagner there are expectations from this model of galaxy formation for the existence of many of these small dark matter clumps in the halo away from Milky Way and so while this was an expectation that was put forth you know basically from simulations there were very firm predictions about if this paradigm were correct how many dwarf galaxies de su 5 [Music] astronomers have long known that the Milky Way galaxy is enveloped in a diffuse halo of stars including some 160 large star clusters [Music] m15 is one of the densest known gravitational interactions among its stars have caused them to pack in tightly so-called globular clusters like this are like pottery shards found by archaeologists at the sites of ancient villages one called ters and five has even managed to survive a fall into our Milky Way it contains a population of relatively metal-poor stars that would have been born 12 billion years ago there should be many more clusters like these in a wide variety of sizes that have simply not had time to enter the disk where are they today when the first round of data from the dark energy survey was released Alex and Keith began combing it for light that could be resolved as stars they saw what they were looking for tiny remnants of the milky way's birth star clusters almost entirely devoid of metal content these dwarf galaxies turned out to be dark matter rich with about ten times the ratio of dark to visible matter as seen in the galaxy as a whole we got this idea that galaxies form from the bottom up you know many many small galaxies and then over billions of years they merge together to form larger galaxies what this means is that the smallest galaxies were also the first galaxies and therefore they're the oldest and when you actually look at these two are galaxies and you study the properties of their stars if I think the stars are very very old that most of them form over 10 billion years ago this realization is central to cosmologies quest to link the early stages and growth of galaxies to cosmic evolution on the largest scales that quest points to the ingredients of matter and energy that produced the very first stars at the cosmic dawn [Music] immediately after the Big Bang the universe was in a hot and very very very homogeneous but it wasn't perfectly homogeneous in fact astronomers have found a telltale pattern in light emitted when the universe was just three hundred thousand years old the so-called Cosmic Microwave Background in this image from the European Planck satellite the colors indicate hot and cold patches produced by tiny variations in the energy of the Big Bang these small fluctuations is small variations of modern then got amplified by gravity and this tiny variations this tiny clumping of matter where the seeds of the galaxies that we see today and this is crucial the amount of variation that we saw early in the universe predicts together with all of the other ingredients that we need for universe predict the rate in which the structures are growing meaning decide the number of clusters of galaxies number of super clusters the shapes of the cosmic wave is determined by that would initial imprinted to trace the evolution of this imprint scientists are using a super computer model to recreate the eruption of stars and galaxies in a cosmic dawn it begins in the darkness of the early universe barely six million years after the Big Bang [Music] gravity draws dark matter in to diffuse halos within them hydrogen gas forms clouds that become more and more dense over time as gravity compresses the clouds they begin to heat up then finally ignite to form the first generation of stars these stars are giants much larger than any today one blows up in a powerful supernova the model shows an environment transformed by the explosion the supernova litters its surroundings with heavier elements created in nuclear fusion carbon silicon iron and more these so-called medals cause surrounding clouds of hydrogen to cool that allows them to collapse [Music] turbulence breaks them into smaller pockets a cluster of smaller second-generation stars now begins to form here's a wider view of the scene almost 400 million years later from data generated by the simulation scientists are working to isolate the dynamics of galaxy evolution stars are being born where filaments of gas shown in blue come together ultraviolet light from these stars begins to strip electrons from hydrogen atoms in a process called ionization that causes surrounding regions to glow with visible light the ionized gas appears as bubbles they are associated with pockets of elevated temperatures shown in red as well as high concentrations of metals spread by supernovae shown in green the simulation reveals a dynamic that shaped the course of cosmic history heating from ionization tends to push the gas out that suppresses the rate of star birth [Music] metals on the other hand allow pockets of gas to cool and fall inward that increases the rate of star birth so instead of stars forming and collapsing immediately in two galaxies the universe becomes a wide mix of hot and cold regions large and small star clusters and pockets of gas amid clouds of dust rich in metals the small dwarf galaxies that astronomers have spotted hovering above the Milky Way are relics of this early period and of the galaxies early years the formation of the first generation of stars also referred to as population 3 stars where these very massive stars to form early in the universe polluting the intergalactic medium and the interstellar medium with unique chemical fingerprints of their own formation different than the sorts of supernovae that we see today and ultra faint dwarf galaxies we have evidence that many of them are actually fossils of this era of reionization where some of them are thought to have formed before we ionization took place and we also have evidence from the chemical abundances of stars in the ultra faint or of galaxies that the chemicals that they were enriched with may have been coming from that first generation of stars itself the supercomputer model gives us a view of cosmic evolution advancing to an age of about a billion years the scene is dominated by star birth and by star clusters merging together into larger formations the universe continues to put the brakes on galaxy growth while star birth spreads heat stifling the flow of gas into galaxies metals from stars and supernovae have a cooling effect that enables this flow many of these early generation galaxies join in larger aggregations take the spiderweb galaxy ten point six billion light-years away a close examination shows that it sits in the middle of a cluster of galaxies fragments this animated reconstruction shows the chaotic scene hundreds of small galaxies and patches of stars are interacting while drying in matter from the surrounding region starting in the early years of the cosmic dawn this simulation shows a slice of the universe in a region 350 million light years across the gravity of dark matter gradually concentrated visible matter into galaxy clusters at the Centers of large galaxies black holes grew to super massive proportions as matter flowed in they generated immense expanding bubbles of gas [Music] these bubbles pushed beyond their galaxies spreading waves of hot gas [Music] the heating from these bubbles would slow the flow of gas into the clusters [Music] that allowed smaller galaxies like ours to form on the margins at the same time black hole winds seeded the wider universe with dust and metals generated by supernovae flash-forward to the present era our galaxy has by no means completed its evolution this simulation recreates the last 60 million years of its history within the dist each flash of light is a supernova as time goes by thousands upon thousands of these explosions seed the galaxy with metals the cosmic dust from which new generations of stars and solar systems are born [Music] though most of the Milky Way stars reside within the disk some orbit far above or below it in the galaxy's halo and occasionally pass through the disk our galaxy today is the product of countless small and large mergers going all the way back to the early universe [Music] its landscapes are the ever-evolving product of star birth and star death the Milky Way is filled with some 200 billion stars born at each stage in the life of the cosmos they are intermixed with clouds of dust and gas all swirling around a bright central region called the Bulge we glimpse its origins within a halo of stars and small clusters some nearly as old as the universe [Music] [Music] from our vantage on earth the universe continues to reinvent itself okay supernovas light has just reached Earth from a nearby galaxy called Centaurus a it's a particular interest to the astronomers its interaction with surrounding dust clouds can reveal the environment in which its parent star lived and died if you're a physicist you you know you have a lab and in your lab you can change the parameters of your experiment and keep testing it when you are on a summer you cannot create stars you cannot create galaxies the universe is your lab and you are a humble collector of light five one five four seven three yeah okay day by day month by month the light of the universe rolls into the data pipeline [Music] here is one slice of the southern sky from the dark energy survey extending roughly half the distance to the edge of our visible horizon it's just the beginning of a grand cosmic census that includes galaxy clusters galaxy types rates of star birth chemical abundances distances from Earth and more when the data from this and the large synoptic survey are combined and laid out in time they promise a record of how the universe evolved since its early moments it is just draw dropping to me that humans can even undertake these big questions and figure out where we are in the universe and as we see the universe changing with time over the last 13.7 billion years it gives us a sense of the cosmic structure formation events that have ultimately led to systems like the Sun being formed discovering the shapes and contours of the universe is only the first step in understanding how it came to be astronomers will sift the data for clues to the initial conditions that came together in the cosmic dawn they'll test theories about the identity of dark matter and dark energy but there is also even this more fundamental question which is you know do these things even exist I think the evidence for dark matters is quite strong we see it it really explains a number of different phenomena dark energy I think is our best current hypothesis for what it's causing universe to speed up but it's it's still on I would say shaky ground is dark energy just the energy of empty space or is it the energy associated with some new fundamental particle in the universe assuming current observations hold up astronomers in the distant future may produce a very different cosmic map one that reflects a universe pushed further apart by dark energy many of the galaxies we see today will have receded beyond our horizons becoming invisible from Earth [Music] our own Milky Way will remain intact still enveloped in the dark matter that spawned it its halo will become increasingly entwined with that of the Andromeda galaxy our larger neighbor it is now moving toward us at about 400,000 kilometers per hour when the two meet several billion years from now their interaction will dominate our night skies from a point of view unique to their time those future astronomers will look out at the horizon and ask how did it all come to be where does it end we asked the same questions today based on our point of view at this moment in cosmic history our technologies are allowing us to see merely to the beginning of time and to track the behavior of the universe on the largest of scales and yet the more we see the deeper the mysteries become [Music] you [Music] you

2021-08-01 10:48

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