Black Hole Apocalypse: What's Inside a Black Hole? | Full Documentary | NOVA | PBS

foreign of all the objects in the cosmos planets Stars galaxies none are as strange mysterious or powerful as black holes black holes are the most mind-blowing things in the universe they could swallow a star completely intact powerful jets that just spew matter out first discovered on paper on the back of an envelope some squiggles of the pen the bizarre solution to a seemingly unsolvable equation mathematical Enigma Einstein himself could not accept black holes as real people didn't even believe for many years that they existed nature doesn't work that way yet slowly as scientists investigate black holes by Irving the effect they have on their surroundings evidence begins to mount that is the proof of a black hole millions of times the mass of the Sun Cutting Edge discoveries show we did it black holes are very real I thought it was crazy I said holy [Music] but what exactly are they if we could visit one what might we see with their immense power do black holes somehow shape the very structure of the universe is it possible we might not exist without them it's it's quite a journey black hole apocalypse right now on Nova [Music] there are apocalyptic objects in the universe engines of Destruction menacing and mysterious black holes scientists who study them find them astonishing black holes can sort of blow your mind I'm amazed that these objects actually exist black holes defy our understanding of nature black holes are the greatest mystery in the universe they're completely invisible yet powerful Beyond imagining they can tear a star to shreds black holes actually will eat anything that comes in their path really want to avoid them at all cost s black holes even Slow Time once thought too strange to be real black holes shatter are very understanding of physics what we're learning they may somehow be necessary for the universe we know to exist they might well be the key players in the universe what are these strange powerful objects outrageous and surprising where are they and how do they control the universe the search for black holes is on and it will be a wild ride across the cosmos to places where everything you think you know is challenged where space and time even reality are Stranger Than Fiction [Music] and we're starting that Journey at a very unlikely place here at a remote location in Washington state where for the first time a radical new experiment has detected black holes yeah it originated over 50 years ago when a few Visionary scientists imagine a technology that hasn't yet been invented searching for something no one is certain can be found the experiment is daring and risky failure could mark their lives forever but they don't fail right here in these facilities they make a remarkable discovery in the early hours of September 14 2015 they record a message it looks and sounds like this just a little chirp but that chirp is epic Monumental the signal traveled over a billion light years to reach us it started far far away and what it tells us is this somewhere in the cosmos over a billion years ago massive black holes Circle each other in a fatal encounter closer and closer they come swirling faster and faster until finally they slam together the black holes create waves that spread outward just like vibrations on a drum a ringing and the fabric of space itself the Collision creates a massive blast putting out 50 times as much power as the entire visible universe sounds out a wave not of heat or light or sound but of gravity this gravity wave is moving its way through the universe at the speed of light the wave Races by stars supercontinents are forming microscopic organisms have just appeared washing over one Galaxy after another after another dinosaurs roam the Earth the wave is still moving it zooms through clouds of dust and then it nears the Milky Way galaxy the ice age is just beginning we're troglodytes drawing in caves the wave reaches nearby Stars Albert Einstein is in the sixth grade the wave approaches as close as Alpha Centauri at midnight on September 13 2015 it is as close as Saturn finally over a billion years after the black holes Collide the wave reaches us it strikes a pair of revolutionary new observatories sites of the daring experiment this is ligo the laser interferometer gravitational wave Observatory the experiment 50 years in the making has finally hit the jackpot and opened an entirely new way of exploring the universe for 400 years almost everything we've observed in space has come to us in some form of electromagnetic energy that little chirp is different what hits the Earth in September 2015 is a gravitational wave a squeezing and stretching of the very fabric of space It produced No Light No telescope could ever see the Collision we needed an entirely new kind of Observatory to detect it that wave is a new and direct evidence of one of the strangest mysteries in our universe black holes most of us have heard of black holes they're invisible powerful we're talking about things that are a billion times the mass of the sun physical entity with infinite density No Beginning No End they pull things in and warp light approach one and time itself begins to change gravity is so intense that a moving clock will tick slower time will become so slow for you that you will watch the entire future of the universe unfold before your very eyes fall in and you'd be squeezed as thin as a noodle fabric of space and time like tooth pick today we know more about black holes than ever before but the more we learn the more mysterious they become the most exotic objects in the universe we don't have the physics to describe them no matter how well you understand them they remain unreachable in some sense okay [Music] so black holes have a pretty Fierce reputation and if you want a villain for a sci-fi movie cast a black hole but in reality what exactly is a black hole and where do they come from you might think a black hole is like this an object but it's not it's a hole in the fabric of space [Music] a place where there is nothing nothing except gravity gravity at its most intense and overwhelming so if black holes are all about gravity gravity at its most extreme what exactly is gravity [Music] [Music] we're all familiar with gravity it's Friday it rules our lives even so for a very long time how gravity actually works was one of the greatest Mysteries over 300 years ago Isaac Newton was fascinated with the behavior of moving objects eventually he figured out his laws of motion they worked so well we still use them today but Newton's Laws can only describe gravity's effects not explain what it is and here's where Albert Einstein comes in Lake Newton he thinks about objects in motion and he wonders what gravity actually is is it a force or could it be something else here's what concerns Einstein take this apple I can't move it without touching it but if I drop the Apple [Music] it moves toward the Earth but what if I take my hand away and the floor in the basement and the floor below that then what happens the Apple just keeps falling Einstein realized that gravity had something to do with falling now if I throw the Apple it falls along a curved path [Music] but imagine I could get the Apple moving much faster eventually if I get the Apple moving really really fast say 17 000 miles an hour its curved path matches the curve of the Earth the apple is in Orbit falling freely just like the International Space Station and the astronauts inside it according to Einstein the apple and the space station and the astronauts are all falling freely along a curved path in space and what makes that path curved the mass of the Earth Einstein came up with a supremely simple concept and that is that space and time is Bent by the Earth and by the Sun and by all the objects in the world so according to Einstein mass of every object causes the space around it to curve and that was Einstein's conception there are no forces anymore there's just objects bending space-time and other objects following the straightest line through it all objects in motion follow the Curves in space so how does the earth move the Apple without touching it the Earth curved space and the Apple Falls freely along those curves that according to Einstein's general theory of relativity is gravity curved space and that understanding of gravity that an object causes the space around it to curve leads directly to black holes but it's not Albert Einstein who first makes the connection between gravity and black holes it's another scientist Carl schwartzshield was a German astronomer head of the Potsdam observatory in Germany ever since he was a teenager he had been calculating complicated features of planetary orbits Einstein unveils his theory of gravity in 1915. Carl schwartzshield is in the German army calculating artillery trajectories in World War One and just weeks after Einstein presented his papers short Shield then on the Russian front quickly got a copy and was mapping the gravitational field around a star Einstein had gotten at it through a series of approximations but schwartzel sitting on the front with bullets and bombs flying calculated an exact solution to Einstein's theory and sent it to Einstein Einstein was astonished he hadn't even imagined that you could solve these equations exactly but short Shield isn't done in his solution to Einstein's equations he discovers something Einstein himself had not anticipated [Music] schwartzell said I can calculate this strange distance from a gravitating object that represents a kind of a boundary schwartzshield mathematically concentrates a Mass for example a star into a single point then he calculates how that mass would bend space and curve rays of light passing nearby as he through his mathematics aimed particles of light or matter towards this point there was this boundary surrounding the point at which the particles would just stop the particles disappeared time stopped schwartzeld has discovered that a concentration of mass will warp space to such an extreme that it creates a region of no return anything that enters that region will be trapped unable to escape even light it's like those roach motels you can check in but you can't check out once you go across that boundary even if you can sail through there's nothing you can do to get out there's nothing you can do to Signal out it becomes this strange cut off portion of space-time what Carl schwartzshold has discovered is that any Mass compressed into a small enough space creates what we today call a black hole Albert Einstein whose own theory of gravity predicts such a thing cannot believe it can happen in the real world Einstein didn't think that nature would act like this he didn't like this idea Carl schwartzshield becomes ill and dies before he has a chance to further investigate his own Discovery Twitter in November 9 19 World War One ends the strange theoretical sphere discovered by Carl schwartzell seems destined to be forgotten nothing but a curious historical footnote [Applause] [Music] and about how fusing Adam's Powers Stars a process called nuclear fusion some begin to wonder if something like a black hole could actually come from a star but not just any Star it would have to be big stars are born in litters and you get a distribution of sizes and masses thousands of little stars and a few big stars very big stars incredibly massive stars are in many ways similar to living creatures humans they have life cycles investigating Stars life cycles in the 1930s two Visionaries subramanian chandrasekar and Robert Oppenheimer this discover that the most massive stars end their lives very differently from smaller ones the life cycle of a star really depends on its mass the mass of a star determines what's going to happen after it finishes burning its hydrogen fuel All Stars start out burning hydrogen the lightest atom using hydrogen atoms into helium working their way up to heavier elements gravity wants to crush the entire mass of the star but the enormous energy released by Fusion pushes outward preventing the star from collapsing stars are stable because you have an outward moving pressure due to nuclear fusion and that's balancing with the inward force of gravity smaller stars can't fuse elements heavier than helium but in the most massive stars crushes heavy all the way up to iron iron is such a massive element it has so many protons in it that by the time you fuse iron you don't get any energy back out iron is a dead end for stars fusing atoms larger than iron doesn't release enough energy to support the star and without enough energy from Fusion keeping the star inflated there's nothing to fight gravity and gravity wins and so the entire star collapses very rapidly trillions of tons of material come crashing down hit the dense core and bounce back out blowing off the outer layers of the star in a massive explosion supernova The more mass the more gravity so if the remaining core is massive enough gravity becomes Unstoppable known Force to prevent the collapse to an infinitesimally small Dot until all its mass is compressed in an infinitely small point [Music] a black hole the theory makes sense but most physicists remain skeptical about black holes Einstein and Eddington all the sort of you know preeminent astrophysicists in the 1930s or 1950s did not believe that they were actually real it remained a solution a mathematical Enigma for a very long time so it took a long time for people to even start looking for them it's not until the 1960s that the idea of a supernova creating a black hole is taken seriously Princeton physicist John Wheeler who had originally been a skeptic begins to use a name from history for these invisible objects black hole the term black hole actually originates in India the black hole was the name of an Infamous prison in Calcutta [Music] still no one has ever detected any sign of a black hole then in 1967 graduate student Jocelyn Bell discovers a strange extremely tiny dead star that gives off very little light a neutron star cold remains of a stellar collapse the neutron star gives astronomers more confidence that black holes much heavier dead stars might also exist [Music] a half century after Carl schwarzshield mathematically showed that black holes are theoretically possible scientists have identified a natural process that might create them death of large Stars so these giant Supernova explosions of extremely massive stars make black holes any star that is born with a mask that's about 10 times the mass of the Sun or higher will end in a black hole so our galaxies replete with little black holes which are the Stellar corpses of generations of stars that have come and gone so what are these invisible Stellar corpses like imagine I'm exploring space with some advanced technology for Interstellar travel so that we could visit a black hole maybe one in our own Galactic neighborhood [Music] this particular black hole isn't very big only about 10 solar masses meaning 10 times the mass of the sun and like all black holes it has an event horizon distinct Edge to the darkness that's the boundary Carl schwartzshield first discovered where gravity is so strong that nothing can escape not even light and that's where we're going thank you as we get closer some very strange things begin to happen look at the edge of the black hole see how the image of distant stars is distorted and smeared into a circle that's gravitational lensing the black hole's extreme gravity bends the path of light passing by so that a single point of light like a star briefly appears as a ring around the Event Horizon I'm now deep in the black holes gravity well and we're going to start experiencing the effects the extreme gravity actually slows down time relative to the Earth from their point of view I appear to be slower but from my point of view time on Earth is speeding up now let's say I want to get even Closer by taking a spacewalk [Music] the way the black hole slows down time is about to get even more pronounced here I can see the shadow of the Event Horizon approaching and my light blinking normally but watching from the ship the closer I move toward the black hole the more slowly I appear to move the pulses are nearly infinitely spaced so it looks as though I'm frozen in time for me everything is completely normal even when I reach the Event Horizon if you waited long enough maybe millions or billions of years the ship would finally see me disappear and that's the last you'd see of me [Music] what's inside a black hole that's still a mystery and even if I find out I can never go back and tell you but I can say this black holes may be dark from the outside but inside they can be bright I can watch the light from the Galaxy that's fallen in behind me and that's the last thing I'll ever see unfortunately the fun is about to end now that I've crossed the Event Horizon I'm falling toward the center where all of the mass of the black hole is concentrated and I'm beginning to get stretched as I fall in the gravitational pull at my feet is stronger than at my head and my body is starting to get pulled apart I'll be stretched as long and thin as a noodle spaghettified and ultimately I'll end up completely disintegrating into my fundamental particles which are then crushed to an infinitely small point Singularity where everything we understand about space and time breaks down or maybe the black hole less than 40 miles across on the outside is as big as a Universe on the inside and as I pass through my particles will join the primordial soup of a new beginning so that's what theory tells us we might experience if we could travel to a black hole [Music] but how can we know for sure how do you investigate something you can't even see there are ways to investigate if something is happening somewhere even if I can't see that thing directly take Yankee Stadium what's happening inside there is there a game going on I can't see the field I can't see any players or baseballs or bats but I can definitely tell if there's activity around the park it's pretty clear something is going on [Music] I can learn just by observing The Happening happenings around the stadium and these do look a lot like Baseball fans [Music] [Applause] and that's the way we investigate black holes by observing the effect they have on their surroundings but what sort of effects how might a black hole reveal itself starting just before World War II two Monumental discoveries are about to radically change astronomy in 1931 Bell Labs engineer Carl jansky picks up mysterious radio waves emanating from deep space then the sky gets even stranger when scientists melt Geiger counters uncaptured German rockets and discover the cosmos is also full of x-rays these discoveries give astronomers important new tools that will revolutionize the hunt for black holes and dramatically expand our vision what our eyes can perceive is a very narrow part of the electromagnetic spectrum if the electromagnetic spectrum were laid out along the Brooklyn Bridge the portion we can see with our eyes would be just a few feet wide electromagnetic radiation includes waves of many different frequencies radio waves microwaves infrared and ultraviolet light X-rays and gamma rays radio and x-ray astronomy open up the sky revealing dim or even invisible objects blasting out powerful energy no one knew was there they began to realize that this very Placid thing that we see out there all this very quiet thing that looks like nothing is happening and the only thing that's moving is the planets found out that there was Madness going out there was chaos out there x-rays come from the high energy end of the spectrum what is creating all this energy this much is certain whatever the source it is invisible to ordinary telescopes and it is hot x-rays come from things which are at temperatures of millions of degrees even tens of Millions one of the first of these x-ray sources to catch the attention of astronomers is named cygnus X1 sickness it was in the constellation cygnus X it was an x-ray Source One it was the first one you found in 1970 Paul murden is a young English astronomer trying to secure his next job I was a research fellow I was coming to the end of my three-year contract and I thought what can I contribute to finding out what these things are Merlin Works in a 15th century Castle surrounded by telescopes a Royal Observatory using the largest telescope in England he begins searching the area of the constellation cygnus swan he decides to hunt for pairs of stars pairs of stars are called binaries they may sound exotic but they're not at all uncommon many of the Stars we see perhaps half are actually binaries pairs of orbiting Stars locked together by gravity murdered wonders is it possible there are binaries where only one of the stars is visible I thought that maybe there was a kind of a star system in which there was a star a northern one ordinary star that made light and then there was another star nearby that made x-rays The Telltale sign of a binary is that the stars are moving around each other so murden begins searching for a visible star that shows signs of motion sometimes it's coming towards you sometimes it's coming away sometimes it's coming towards you sometimes coming away when the star is moving toward us it appears more blue wavelength of its light gets shorter moving away it appears more red as the wavelength of its light gets longer this is known as Doppler shift [Music] after looking for color changes in hundreds of stars in the area of cygnus murdon spots a possible suspect a visible star whose light is Shifting as though moving around it very clearly was a binary star a double star the star was moving around and around with a period going around once every 5.6 days but whatever it's good there was no Trace in the spectrum of the second star there was one start there that wasn't the second star there Merton has a binary pair in which only one star is visible the second object emits x-rays has enough mass and gravity to dramatically move a star but gives off no light could it be the corpse of a star massive enough to become a black hole The crucial issue in deciding whether cygnus X1 was a black hole was to measure the mass of the X-ray emitting object it would have to be very massive at least three times the mass of our sun if not it's probably just a neutron star collapse star that's dense but not heavy enough to be a black hole so The Observers needed to come up with a conclusion that the dark object the X-ray animating object in cygnus X1 was heavier hopefully substantially heavier than three solar masses from his observations Merton is able to make an estimate of the mass of the invisible partner and the answer came out to be six times the mass of the Sun so there was a story then that cygnus X1 was a black hole and the key to the argument was that the mass of the star you couldn't see was more than three solar masses where I'd finished writing it all out I sat back and thought it's a black hole [Music] this would be the first actual detection of a black hole it's a huge claim and Merton will have to convince Skeptics starting with his boss on the Royal Sir Richard Wooley he didn't really go for black holes it's all fanciful a lot of people in California were talking about this there are a lot of funny people in California you know a lot of hippie type people people like theorist Kip Thorne so I was nervous about I was nervous about the scale of the um of the discovery and actually so were other people all around me I was working with a fellow scientist Louise Webster and we were modest about the claim that we were making because we knew what people would think of it and if you look at the paper we published it just mentions the word black hole once right at the end we think this might be a black hole the Palmer and Louise Webster paper appears in September 1971. other astronomers agree it could be a black hole but no one knows for sure three years later Kip Thorne and the noted British physicist Stephen Hawking make a now famous wager about cygnus X1 we made a bet as to whether cygnus X1 really was a black hole or not the bet is partly ingest both men hope it is a black hole but Hawking not wanting to jinx it vents against his own wishes [Music] and I claim it is a black hole and so we signed that bet in December 1974 and gradually the case that it really was a black hole became stronger and stronger and stronger so in June of 1990 Stephen broke into my office and he thumb printed off on this bed Conceited the bet in my absence I came back from Russia and discovered that he had conceded Now by 1990 the evidence of cygnus x1's mass may be strong enough to settle a bet between two friends but the original estimate wasn't precise enough to be definitive in order to calculate mass Paul Merton had to rely on rough estimates of the distance to sigus X1 which varied by a factor of 10. and the question wouldn't be answered for another 20 years until astronomer Mark Reed became intrigued by the puzzle [Music] an astronomer at the Harvard Smithsonian Center for astrophysics when he sets out to conclusively prove that cygnus X1 is a black hole by measuring its precise Mass thank you but how can you measure the mass of an invisible object using laws developed by German astronomer Johannes Kepler in the 1600s it's possible to calculate the mass of a celestial object but only if you know its distance in astronomy is absolutely fundamental if you don't know distance you don't know what the object is could be a very nearby Firefly like thing it could be a very distant huge star much much bigger than the Sun so to get the true precise Mass this XY and confirm that it is a black hole Reed needs to know how far away it is but how can he measure the distance to a star the secret lies in a familiar phenomenon parallax it's what our eyes and brains use to see in three dimensions you can put your finger up at arm's length look at it and close one eye I'm closing my left eye and I'm looking at my finger relative to the wall in the background there and now if I open my eye close my right eye I see my finger has appeared to move with respect to the original position and that's because our eyes are separated and we view from different Vantage points to use parallax to measure distance to an object in the sky astronomers let the motion of the earth provide the two different Vantage points imagine cygnus X1 is right here and the Earth and the Sun are over there now the earth goes around the Sun once a year and in the springtime the Earth ends up on one side of the Sun and we observe cygnus X1 along a ray path like this and six months later the earth goes around the Sun to the other side we get a different vantage point from cygnus X1 now he has a triangle that goes between the Earth at its two positions and cygnus X1 we know the base of the triangle the diameter of Earth's orbit and the principles of geometry tell us that all we need to calculate the distance is the size of the angle at the top and we measure this very small angle here at the point at cygnus X1 and then from direct geometry we can calculate the distance to cygnus X1 and from that and for a very accurate Mass the concept is simple but cygnus X1 is so far away that the angle to be measured is minuscule a tiny fraction of one degree it's smaller than the angle span by Abraham Lincoln's nose on a penny in San Francisco viewed from New York because the angle is so very tiny it can't be measured by any one telescope [Music] but Reed's team has a solution we take 10 radio telescopes that are spread across the continental U.S and to Hawaii and to Saint Croix in the Virgin Islands we use these telescopes simultaneously and we synthesize in a computer telescope that has the diameter of the size of the Earth that gives you incredible angular resolution using this technique Reed's team determines that cygnus X1 is 6 thousand light years away with the new distance we got the 6 000 light year distance we were able to determine that the mass is about 15 solar masses easily a black hole 40 years after it was identified as a possibility cygnus X1 is now widely accepted as the first confirmed black hole it's an understated paper and the fact that my name was on it and Louise Webster's was on it did us a lot of good in our careers I think as a result of this discovery I got offered a permanent job and it was a great celebration for the family so it worked out very well for me as well as getting the intellectual satisfaction of solving a problem [Applause] so finally after years of speculation we have a real black hole not only that but a black hole that's blasting out X-rays and has a companion star if we could visit in my imaginary spaceship what would we see [Music] since to cygnus X1 has been established at 6 000 light years from earth and its mass is 15 solar masses or 15 times the mass of the sun and cygnus X1 is surrounded by an accretion disk a disc shaped cloud of gas and dust outside its Event Horizon the point of no return as gravity pulls matter toward the black hole the cloud starts rotating just like water being pulled down a drain within that accretion disk particles closest to the black hole whip around at half the speed of light it's like a giant particle accelerator in space but why does it emit x-rays as those particles race around they Collide which Heats them up to millions of degrees when they get that hot particles blast out X-rays and it's those x-rays that first let astronomer Paul Merton to investigate this black hole nearly five decades ago and there's something else about cygnus that's different it has a companion star this blue supergiant star orbits the black hole once every 5.6 days it orbits so close to cygnus X1 that the black hole strips material off the star and pulls it into the accretion disk some of that material will cross the Event Horizon and get swallowed up but not all of it some of the stuff actually comes back out before ever entering the black hole kind of like a toddler eating half the pasta ends up on the floor half of it maybe on the ceiling and some of it in the mouth one of the most striking and enigmatic features of cygnus X1 is its enormous jets these beams of particles and radiation stream outward from cygnus's North and South Poles perpendicular to the accretion disk still a lot we don't know about these Jets but they are tightly focused and extremely powerful blasting out at nearly the speed of light and extending well beyond cygnus when gas gets to these high temperatures and produces the light there's also a little bit of a magnetic field that forms around them and we don't understand exactly how but these magnetic fields help collimate these massive outflows from black holes powerful hoses if you will that just spill matter out so that's cygnus X1 if we could see it up close a growing feeding black hole with huge Jets blasting particles way out into the universe they're almost these breathing fire eating demons if flicker they have bursts it's a very violent Fireball very active what was once a bizarre mathematical Curiosity has now become quite real after Decades of skepticism scientists now accept that burned out corpses of large Stars can trap light inside them warp space and time around them attract matter and accelerate it to mind-boggling speeds black holes seemed like such a radical idea that we shouldn't accept it but bit by bit the evidence for black holes has gotten stronger and stronger and we've seen these amazing things at least 20 black holes have been found in our galaxy x-ray binaries like cygnus X1 and there are probably Millions more of these massive Stellar corpses in our galaxy alone still a stunning surprise awaits everything astronomers think they know about black holes and much of what they believe about the universe itself will be upended by a shocking discovery the revelations begin when radio telescope surveys of the sky detect mysterious hot spots emitting radio energy they were coming from what looked like stars because these objects resemble stars but were discovered through radio signals astronomers name them quasi-stellar radio sources quasars but are they stars or not the first step in investigating them is to figure out what they're made of [Music] astronomers analyze the electromagnetic energy they emit every element has a unique spectral fingerprint for example carbon [Music] helium hydrogen these lines reveal the chemical makeup of a star but the spectrum of a quasar turns out to be incomprehensible they looked at it and it was gibberish it didn't look like there were any emissions from elements that they knew what are they missing there has to be a clue somewhere finally in 1963 Caltech astronomer Martin Schmidt finds it hiding in plain sight buried in the Quasar spectrum is the fingerprint of hydrogen he noticed something familiar but it was in the wrong place Prince of hydrogen had been shifted way off to the red it was hard to spot because the spectral lines of hydrogen were radically shifted toward the lower frequency end of the spectrum and that could only mean one thing Quasar is moving away from us at Fantastic speed but astronomers have almost never before seen light shifted to such an extreme [Music] like a familiar sound shifting too low to understand and the light from quasars has shifted to such a degree that hydrogen is unrecognizable this extreme amount of shift means quasars are racing away from us at blinding speeds the reason it's the legacy of an event that occurred almost 14 billion years ago the Big Bang beginning of our universe and ever since the universe has been expanding caring with it all the objects it contains including quasars almost no one had ever seen anything moving away at that high speed this made this object almost the furthest away thing that had ever been seen which meant the thing itself had to be so luminous and you had to account for that 2 billion light years away putting out the energy of a trillion Suns each second what could possibly create that no one had any idea what could be powering these things where could all of this energy come from if you work out through calculations it can't be chemical energy they knew it couldn't be nuclear energy there's no way a quasar could be a star no amount of nuclear fusion could produce that much star power the only engine possibly put out that much energy is gravity [Music] gravity in everyday life we can overcome gravity easily but when concentrated to an extreme buy a black hole gravity is overwhelmingly powerful a handful of scientists start wondering could quasars perhaps be powered by gravity engines what if the energy blasting out from quasars is coming from Bright accretion disks around black holes [Music] produce that kind of energy that kind of brightness it has to involve a black hole but not just any black hole whatever was the source of the emission from a quasar had to be massive how massive well millions or billions of times heavier than the Sun millions or billions of times heavier than the Sun cygnus X1 is only 15 times the mass of the sun the black holes powering quasars are an entirely different category of black hole super massives and they seem to be located in the centers of galaxies but what about our own Galaxy could there be any supermassive black holes closer to home Center where any supermassive would be found lies in the direction of the constellation Sagittarius the Archer now Sagittarius isn't just any constellation it's in the direction of the center of our own Milky Way galaxy we live inside the Milky Way we can't see the Galaxy the way a space traveler would [Music] but I can use my trusted imaginary Star machine to show us the Galaxy from the outside our home is a spiral galaxy hundreds of billions of stars drawn together into a gigantic disc it's wide about a hundred thousand light years across but it's relatively thin only about a thousand light years thick and the whole spiral slowly rotates our solar system is here and here 26 000 light years from the Earth is the center which we see in the direction of Sagittarius in this Dent Center there are millions of stars and lots and lots of dust and gas so that's the view of our galaxy from the outside thanks to my imaginary technology but since we live inside the Milky Way when we look towards the center we're looking through much of our own Galaxy which means it appears to us as a band of stars and dust across the sky a Milky Way [Music] deep inside this band of stars and dust could a supermassive black hole be lurking in the 1990s astronomers grow determined to solve the mystery to hear through the murky Milky Way and learn what if anything is at its Center one of them is Andrea guests guest takes on a daunting challenge she will try to track individual Stars orbiting the center of the Galaxy the essence of this experiment comes from watching stars orbit the center of the Galaxy so you want to find the stars that are as close to the center of the Galaxy as possible which means that I want to get access to the largest telescope I can possibly get my hands on and that means coming here [Music] the summit of Mauna Kea a dormant volcano almost 14 000 feet above the beaches of Hawaii high altitude and low humidity make this the ideal place for astronomy [Music] Keck Observatory one of the largest in the world but despite its size Keck has the same problem as all telescopes on Earth [Music] atmospheric distortion think about looking at a pebble at the bottom of a river the river is moving very quickly and your view of that pebble is distorted like a river the Earth's atmosphere is constantly changing bending light like a fun house mirror to compensate for this Keck Pioneers the scientific use of a Declassified military technology called Adaptive Optics first they shine a laser into the sky creating an artificial guide star the turbulent atmosphere distorts the guide star pewter knows what it should look like and adjusts the telescope mirror accordingly you look at yourself in a circus of funhouse mirror you look completely distorted and the goal of the Adaptive optic system is to introduce a second mirror that's the exact opposite shape and make you look flat again [Music] very deep inside the telescope the deformable mirror changes shape up to 2 000 times a second to reverse the atmosphere's distortion and it has allowed us to take the sharpest images ever obtained of the center of the Galaxy the sharpness of those images allows Gaz to make out individual Stars near the center a huge advance in astronomy she begins recording their positions in 1995. and every year since then we've taken an image just take a picture putting those annual snapshots together creates a time-lapse movie of Stellar orbits and what those movies reveal is astounding the stars are whipping around the center of the Milky Way at phenomenal speeds are moving at several thousand up to ten thousand kilometers per second or 10 million miles per hour they're they're really hauling to go that fast the stars must be orbiting something extremely massive the mass that we infer is 4 million times the mass of the Sun what could be four million times the mass of the Sun yet be completely invisible that is the proof of a black hole and not just any black hole a supermassive silent and sleeping right in the center of our own Galaxy in fact this is the best evidence to date that we have for the existence of supermassive black holes not only in the center of our own Galaxy but anywhere in the universe [Music] supermassive black hole four million times the mass of the Sun and the very center of our own Milky Way galaxy from a cosmic perspective it's right next door and it raises a profound question there are billions of galaxies out there if ours has a supermassive black hole at its Center and if Cuisines are found at the centers of their galaxies what about the others are there black holes at the centers of galaxies if they are how common are they we simply didn't know could astronomers ever hope to find what lurks at the centers of other galaxies millions of light years away as guests did in our Milky Way it would take another innovation in astronomy to make that possible discovery when the Hubble Space Telescope starts delivering clear images of distant galaxies a team of astronomers gets to work they become known as the nukers because their focus is galactic nuclei the centers of galaxies one of them is Todd Lauer step one we take a picture of the Galaxy with the Hubble Space Telescope it shows us where the stars in the galaxy are tells us its structure and exquisite resolution key to finding supermassive black holes is to learn how fast the stars in the galaxy are moving galaxies outside our own are much too far away to measure the speed of individual stars but by analyzing the way light is shifted from Blue to Red at different points in the Galaxy astronomers can put together an average speed of stars orbiting the center accurate enough to create a replica in a computer Second Step where is to try to model the observations and we actually do that by building models of galaxies in the computer it's known as short Shield's method developed by Princeton astronomer Martin schwartzshield son of Carl schwartzell his mathematics first described the possibility of black holes Martin schwartzfield's trick was he would actually build up a model of the Galaxy that not only had where the mass was but it also had how the stars were moving for each Galaxy they investigate the nuker's painstakingly build a computer model and then using trial and error adjust the parameters of mass and velocity trying to make the model match the original observations they got from the Hubble okay let's try a star here let's try one over here let's have it go around this way let's have this one go around that way and we do this thousands and thousands of times until we build up a library of how stars in orbit in this galaxy is when observations of the model match the observations taken with the Hubble Space Telescope that doesn't happen the models are missing something we try it again and again and again all with no black hole yet and see gee we really can't get the observations explained by the model only when they add an enormous invisible mass at the Galaxy Center does the model match the Hubble observations almost always we have to put in a black hole at the center we can't match the observations without a black hole in the model of roughly three dozen galaxies that the nukers investigate virtually all of them require a supermassive black hole that other observations have made us even more certain that supermassives and galaxies go together every Galaxy we've looked for one we have found a supermassive black hole in its Center it's a stunning revelation supermassives once an entirely unexpected category of black holes may be common not only the center of our galaxy but of all galaxies take Galaxy M31 also known as the great Andromeda Galaxy two and a half million light years away on a clear night you can see it from Earth but even with the Hubble Space Telescope we can't make out precise details of its Center still we're pretty sure there's something extremely massive hiding there what if we could take a closer look what if we could visit a galaxy far far away [Music] thank you as we enter the outer part of Andromeda we're still too far away to see what's lurking at the center but we can make out a dense cluster of stars in the core and that could be a sign that there's a giant black hole nearby billions of years ago it would have been surrounded by gas and stars and other small black holes the black hole may have powered a quasar mad be blasting out blinding radiation over hundreds of millions of years it would have consumed all the available gas and the closest Stars [Applause] foreign but it has some distinctive features we've never seen before first it's colossal if it were dropped in our solar system Mercury Venus Earth and Mars would all be trapped inside the Event Horizon that's big but it's nothing compared to the sheer Mass a hundred million times the mass of the sun and the destruction won't end there Jupiter won't last long the gravitational field of the supermassive will grab hold and swallow it whole eventually Saturn will suffer the same fate the outer planets might survive but in cold and dark orbits this black hole rotates rapidly distorting and dragging the fabric of space-time like all black holes The Event Horizon is completely featureless remember there's nothing there it's just a boundary that conceals the interior but the accretion disc can tell us a lot about what's going on that's the fiery ring of gas and dust around the black hole to explore the accretion disk the disc is spinning at an incredible speed as much as half the speed of light if Jupiter moved that fast it would complete its entire orbit in a few hours the region around the black hole is a cosmic tornado this warm is caught in the Whirlwind too they're like tracer Tracer storm to map movement the middle robot can send us images it's Following the Leader like a race car speeding around the track from here the extreme warping of space-time around the black hole plays crazy tricks on our eyes it looks like there's one accretion disc whipping around the equator and another arcing over and under the poles but that's an illusion the black hole's extreme gravity bends the path of light emitted behind the black hole and makes it look like the accretion disk is both above and below there's actually nothing around the poles it's just the passing light rays that's gravitational lensing again drawing much closer to the event horizon the gravitational lensing would become so extreme that one of my robots could look straight ahead and eventually see its own back the light forever trapped in an eternal Circle so that's our tour of the supermassive black hole at the center of the Andromeda Galaxy pretty amazing also amazing nothing in the mathematics LED scientists to imagine that black holes could get that big as strange as they are ordinary Stellar Mass black holes were at least predicted by Theory supermassives are a complete surprise for the Stellar Mass black holes people thought about them from a theoretical perspective and then we found them observationally this supermassive black holes this story has been inverted we've actually found evidence of them observationally first and now we're working on the theory of how did these things come into being we already know that stars can collapse to create ordinary black holes supermassives are bigger by many orders of magnitude cygnus X1 is 15 times as big as our sun supermassive at the center of our Milky Way is 4 million times as big as our sun the one in the Andromeda galaxy is a hundred million times as big as our sun and it's not the biggest not even close there are super massive 10 even 20 billion times the mass of our sun thank you how is it possible to make such gigantic black holes could supermassives have come from collapsed Stars that seems very unlikely we don't know any stars billions of times bigger than the Sun we know about black holes you might get from a dying star they have several times the mass of the Sun contained within them but millions of times the mass of the sun if that's the case a dying star cannot have possibly made it so do these super masses millions or even billions of times heavier than the sun somehow just grow packing it on like voracious Giants the wild thing about black holes is that they feed they're constantly devouring anything that comes within their sphere of influence so they grow but how exactly do they grow what do they eat and where do they find it we believe that black holes grow by accretion of gas and the way this works is that you have a lot of gas around in the center of a galaxy and this gas would then assemble and form an accretion disc the accretion disc is made up of hydrogen helium and other elements in a gaseous form the immense gravity of the black hole pulls the gas in toward it as it swirls around it orbits closer and closer to the black hole and the feeding begins stuff in the inner regions would get slowly pulled in sped up will reach the Event Horizon and then that's it [Applause] whatever gas crosses the Event Horizon disappears forever the black hole has absorbed that material so it actually adds to the mass of the black hole this is one way a black hole can grow gradually nibbling gasp and dust but it's not the only way cygnus X1 has been slowly stripping Material off a nearby star process that will likely go on for thousands or millions of years but what if a black hole could rip an entire star apart in just a matter of years or even weeks that would be a very violent event and a team of Space Explorers is on the lookout operations control center for a Space Telescope I'd be five by five how many we show beginning of track at zero three Thirty the Chandra x-ray Observatory 16 minutes one six orbiting up to 86 000 miles above the Earth Chandra takes high resolution images of objects that emit x-rays this is one a short-lived extremely violent event called a transient fascinates James gioshon supernova destruction of planets by their host Stars I'm just fascinated with destroying things for science is investigating a mystery discovered by a colleague Lin this blur on James's screen is actually a massive sudden burst of X-ray energy caught by accident this little smudge popped up in the background of this image and given its great distance it's actually tremendously bright could it be a black hole caught in the act of being born in the Violet collapse of a huge star perhaps but the intense radiation released by Supernova would only linger for a few months so how long has this mystery object been blasting out x-rays to find out they look at images of that same part of the sky taken at earlier dates 2015. 2011. 2008. 2005 July 2005 April no x-rays detected but the x-rays are there just three months later in July and the powerful bright signal has continued for more than 10 years from July 2005 to the present far too long to be a supernova so what could it be [Music] a black hole that's not feeding is quiet and completely dark it won't show up on any telescope but a black hole that is feeding is different when it feeds it blasts out x-rays so could this be a black hole that suddenly begun devouring something big what effect will this have on anything that comes near what would it do to a star that wanders too close well it will Flay a star layer by layer ultimately devouring the entire star unlike cygnus X1 this is no mere niblet this is a 10-year Feeding Frenzy a massive black hole devouring an entire star in a cosmic blink of an eye it's the result of a chance Collision when an unlucky star wanders too close and the black hole's extreme gravity actually rips it apart the Gravity from the black hole will progressively get stronger and stronger as the star gets near and at that point the star will begin to deform it's called tidal disruption it's similar to the way our moon's gravity easily moves all the world's oceans the tides caused by a black hole would be billions of times stronger and much more violent you have these events where a star could be ripped apart by the black hole so you would see sort of a plume of light from the last gasp of the material in the star but there is a chance for some part of the star to escape as James illustrates as the star is elongated by the black holes tidal forces it will essentially be feeding the black hole at the same time as half of it is trying to escape so everything above this point approximately will have the chance of leaving the Galaxy it's moving that rapidly and everything below this point will fall back onto the black hole and eventually be consumed by it [Music] so this is another way for a black hole to gain weight unlike the slow steady nibbling of cygnus X1 this black hole is devouring most of an entire star in one gulp but whether a black hole feeds Suddenly by swallowing half a star or steadily through accretion astronomers still face a problem when they try to understand how supermassives got so big the timing problem trouble begins with the very oldest supermassives quasars those very bright very distant and ancient objects first discovered in the early 1960s conundrum was when we started finding these quasars very bright quasars very early on in the universe [Music] so much energy that they have to have very massive super quasers are extremely far away which means they're part of the very early Universe which began nearly 14 billion years ago right quasars 100 million years after the big bang a fraction of today's age and they're enormous so billion solar mass black holes these behemoths had to be in place when the universe was about 550 million years old now you have a problem because you have to grow something really big really fast and you are bumping up against sort of physical limits whether a black hole is nibbling or gulping down its meal it turns out that accretion how black holes feed has a speed limit named after English astronomer Arthur Eddington the Eddington limit will not allow a black hole to feed too fast because of the light blasting out from its own accretion disk light has a pressure so photons can impart a force on something we see this in winds from Stars light is pushing out gas so there's a limit to how fast you can feed a black hole before its own Luminosity quenches its own growth so given the speed limit how did early supermassives quasars get so big so fast could there be a way to bypass the speed limit entirely the problem till time itself how do you grow them to a billion times a massive sound what are the conditions that you need for that kind of growth some scientists are now asking what if there's a way to create a black hole that's already much more massive from birth giving it a head start if there was a physical mechanism that would allow you to make a black hole seed which was much more massive from the get-go then the timing crunch is not as much of an issue and the growing problem is not as acute [Music] the answer some believe is to create a black hole directly from a cloud of gas a scenario called direct collapse thank you it starts with gas clouds made of hydrogen helium and other elements this same raw materials from which stars are born the denser clouds will start to collapse under their own gravity not collapse parts that are more dense will collapse more quickly and so what happens is the cloud fragments those fragments continue collapsing until the hydrogen atoms within them begin to merge nuclear fusion begins and stars are created but what if a Giant gas cloud collapsed without making Stars physical conditions that would allow you to form a very large gas disk prior to the formation of any stars so this gas disc starts getting unstable that would allow the mass to sort of flow into the center very very rapidly and make a very massive black hole something we've all seen in nature and tornadoes to bathtubs a Vortex but on a super massive scale if you're in a bathtub and you pull the plug out and you see the water flowing in in a Vortex very fast down to the center that's exactly what happens direct collapse might be a way to create very large black holes early in the universe from enormous gas clouds completely skipping the star stage because they would be so large already at Birth these direct collapsed black holes would have a head start helping them to quickly grow into the enormous young supermassives we see in the distant universe a good potentially have these direct collapsed black holes so black holes whose original masses seed masses the initial masses are about 10 000 to maybe a hundred thousand times the mass of the Sun and that they form from the get-go with that Mass direct collapse may explain how enormous early supermassives got their start but there's another fundamental question about supermassives what is their role in the universe is there existence just a matter of chance or are they connected in some larger way to the very structure of the cosmos supermassive black holes don't exist in isolation they seem to live in partnership with galaxies collections of millions billions or even trillions of stars bound together by gravity galaxies are the fundamental building blocks of our universe so are the supermassive black holes at their centers somehow fundamental to their very existence confirm we'll have a supermassive black hole in their Center it could be that instead of Simply being Oddities that they are a key component to gas is a key component to the universe we've come in a very short time to realize that they likely inhabit the centers of all the galaxies really only happen if there's some symbiotic relationship between the evolution of a galaxy and the supermassive black hole in its core what could that relationship be one entry [Music] the bigger the galaxy is the more massive the black hole appears to be so these black holes at the center seem to know about their larger scale environment so which comes first the Galaxy or the supermassive black hole it's not that simple it appears they somehow grow in tandem it's hard for one to form first and affect the other so today we think that whatever formed one had to form the other as a byproduct of that process and that there has to be some feedback mechanism between the black hole and the Galaxy that keeps the growth of the two in lock sync The Way galaxies grow is by forming new stars from clouds of hydrogen gas essentially the star formation just like gas is the fuel for our cars and so if you run out of gas you run out of new stars so our super massive black holes somehow interfering with star formation when a black hole is growing a tremendous amount of energy is being liberated and sent out into the Galaxy and so we think that some of that energy goes to warm up gas and gas that's too warm will not form Stars anymore [Music] the heat produced by a growing black hole makes it impossible for stars to form nearby and so one way that a growing black hole can influence its host Galaxy is by quenching the star formation in effect the growth of the supermassive determines whether or not its host Galaxy grows or stagnates they have a kind of eating phase and then a quiescent phase so they seem to be involved with the formation of the Galaxy in that way and then stabilizing of the Galaxy at the same time so these mysterious supermassives may actually control the building of the universe not So Much by their size but by the way the energy they generate shapes galaxies by mass if you count up all the black holes in the universe the tiny ones as well as the supermassive ones the ultra massive ones black holes are nothing however energetically how much power the Galaxy gets and at what time as it assembles seems to be dictated by the central black hole so they might well be the key players in the universe in the next two years NASA plans to launch the James Webb Space Telescope Humanity's most powerful telescope ever the James Webb is designed to look in the infrared allowing it to see farther back in time than Hubble getting a look at the first stars and galaxies that formed after the big bang hopes are high that the James Webb Space Telescope will help solve many of the remaining mysteries about the earliest supermassive black holes James Webb Space Oscar is tuned specifically to observe the early Universe when galaxies were being born that could give us deeper understanding of how you end up with a supermassive black hole in your Galaxy to begin with technology is moving really fast and as a result we have really fundamental new views of the universe I think we are really living in a golden era of astronomy and the James Webb Space Telescope isn't the only new development that promises to solve some of the Mysteries around black holes those Peaks I believe have infrared components a group of scientists led by Chef Doleman is now attempting The Impossible to take a picture of a black hole it's interesting that we can say something about the accretion flow near the black hole at all and if some of this linear Behavior survives maybe we'll have a way of interpreting it project is called The Event Horizon telescope the basic goal of the Event Horizon telescope is really to see the unseeable is to bring into Focus something that science has told us for many many years is precisely something we can't observe the the black hole [Music] their primary target is Sagittarius A star super massive in the center of our Milky Way galaxy they're using a Global Network of radio telescopes we need good weather at eight different telescopes all around the world and that is a tall order but if black holes are invisible what exactly do they hope to photograph what we're trying to photograph really is the shadow so as this gas around the black hole Swirls inwards and actually hits the Event Horizon it leaves a silhouette a very well defined shadow on the surrounding light so really it should look like a donut with its very well defined hole and that's the picture that we are after if I convert it into frequencies I get it to Pi Square there the team has conducted their first observing run and is processing the data now can you say the velocity it's hoped that these new technologies will give us an unprecedented view of black holes in our universe but there is one new technology that is already delivering results and that brings us back here to ligo a player in the black hole drama to an idea that took root way ahead of its time gravitational waves with general relativity his theory of gravity Einstein predicts that when an object moves it can create ripples in space and time an actual squeezing and stretching of space itself one of the Holy Grails of 20th century physics was to detect these gravitational waves that was not easy to do with general relativity because all the effects that you could think of were infinitesimally small very very difficult to measure the thinking was if gravitational waves could be measured it would confirm Einstein's prediction and there could be an added benefit it might also prove the existence of black holes and help solve the mystery of how supermassives grow but how to detect gravitational waves in 1970 the problem caught the attention of a young experimental physicist Ray Weiss Rey had the perfect background to hunt for gravitational waves for decades he'd been working with more familiar waves sound waves we were immigrants we were German Jews and a lot of our friends were very very interested in music Ray devoted himself to coaxing every subtle Nuance he could out of recorded music those records had a terrible problem when the music was loud it sounded wonderful when the music was real quiet and slow what you heard was this shh like that a hissing noise and that was so annoying the lessons he learned trying to eliminate noise in recordings will pay off later when Rey turns his attention to detecting gravitational waves we have to understand how a gravitational wave does its dirty work problem gravitational waves [Music] it's from something that is in some way moving and oscillating sound wave come compresses and expands air gravitational presses and on space and everything in it if a wave came through the Earth it would cause space to expand momentarily and then contract again keeps doing it she was just a thing that goes I don't know like that so how to measure the extremely tiny expansion and contraction of space [Music] Rey's idea was to use light send a beam of light from one place to another and measure the time it takes to get there that's how the exact distance to the moon was calculated bouncing a laser beam from the earth off a mirror left behind by Apollo 11 astronauts [Music] from the duration of the round trip scientists could determine the distance [Music] Rey came up with an ingenious design for an instrument that uses lasers and mirrors to detect the faint expansions and contractions of space that would be caused by a gravitational wave it's called a laser interferometer works by firing a laser into a splitter half of the light continues Straight Ahead towards one mirror while the other half is sent towards another mirror the distant mirrors bounce the light beams back where they rejoin at a photo detector if the distance is the two beams travel are exactly the same the system is designed so the two beams cancel each other out the detector sees nothing you set the trap to measure the gravitational wave now comes the gravitational wave that's coming let's say at this structure if a gravitational wave passes through it briefly changes the length of the arms the light beams no longer arrive back at the same time to cancel each other out a gravitational wave hits light appears at the detector trap has sprung that's the basic idea it's a very straightforward measurement [Music] clever idea and simple in principle but the devil and the Nobel Prize lie in the details difference in length between the two arms would be tiny Beyond imagining how tiny will take the size of an atom is less than that go down by a factor of a hundred thousand that's the nucleus of an atom it's less than that it was a hundred times below that so we're talking about really itsy bitsy teeny weeny I thought it was crazy I think everybody's initial reaction to the idea was this is going to be impossible in 1973 Kip Thorne puts his skepticism on the record in a classic textbook doubting it will ever work but Kip has never heard Ray Weiss explain his plan in detail when he does we spent the whole night talking and so I said no no it's very possible and within no time at all 20 minutes maybe half an hour Kip was solidly understanding this thing and he says yep and I ate Crow the rest of my career because once I had talked with Ray about it in detail I decided I would spend a large fraction of the rest of my career helping the experimenters [Music] sums of money to bring Rey and Kip's Vision to reality getting ligo funded was extremely controversial hundreds of millions of dollars to detect a signal that had never been seen before there were many people who feared that ligo would suck the money out of the room though there was a lot of controversy what everybody could agree on was this was extremely difficult with such a sensitive instrument one of the biggest challenges is Ray Weiss's old HiFi nemesis noise ground motion the seismic motion of the earth acoustic noise sound everything would tend to move that mirror turns out even The Emptiness of a total vacuum creates a potentially crippling problem at subatomic distances the weird randomness of the quantum World causes a Ruckus In the mirrors Quantum noise is due to Quantum fluctuations these mirrors are doing what an electron does inside an atom they're jiggling around [Music] Exquisite sensitivity extreme vacuum hundreds of thousands of electronic circuits ligo is one of the most complex instruments in the history of science and as a final means of eliminating false signals they build not one but two complete installations one in Washington State and another in Louisiana and so the ligo designers did it right they designed more than one detector separated from one another by great distances so that if you detect something in one and not in the other then you know go back and check your electronics check to see if it was April Fool's Day and somebody didn't just tweak the knobs early fall 2015. both locations are operating but the first official science run has not yet begun they're still testing in the early hours of Sunday September 14 2015 a scientist in Louisiana makes a fateful decision foreign Robert Schofield has been working all weekend doing final calibrations alrighty let's take a spectrum he has one last test so let's see where this computer is getting its power but it's late and the equipment is not cooperating it was about four or so in the morning and we still had about another hour of work to do and we were like yeah things aren't working so well and I'm really tired let's not do this last hour or so of work they call it a night and 40 minutes later and Silence of their inactivity they opened the door to history powerful gravitational wave rumbles through both detectors Louisiana and Washington had Robert Schofield worked 40 more minutes that night with the instruments in test mode a signal that had been on its way for 1.3 billion years would never have been recorded I like to say you know one of my biggest contributions to ligo has been my laziness that day [Music] I got an email from somebody here saying hey you would look and look at this place on the web [Music] I looked at that and I said holy it was so strong that you could see it by eye in the data it was too good to be true but it was true in fact it was loud and surprisingly clear and it just sang at you the Steelers standing up signal lasted less than a second but in that briefest of moments it delivered a cosmically profound message more than a billion years in the making proving the existence of black holes what we saw in the signal involved oscillations of the mirrors that were slow at first became faster and faster and faster and this was precisely the kind of behavior that you would expect from gravitational waves caused by two black holes going around each other spiraling together holes 59 times the mass of the Sun the other 36 times the mass of the Sun whipping around each other hundreds of times a second finally completing their act of mutual destruction by merging creating a single larger black hole of 62 solar masses the violent merger converts some of the mass into an apocalyptic release of energy beyond anything ever before witnessed Collision in effect creates a very invariable storm in the fabric or the shape of space and time as though you had taken Three Sons you had annihilated them completely converted it into gravitational waves power was 50 times higher than the output power of all the stars in the universe put together in a fraction of a second but the most powerful explosion that humans have ever had any evidence for with the exception of the Big Bang since that very first signal in September 2015 ligo has detected several more collisions of black holes in October 2017 Ray Weiss Kip Thorne and ligo's former director Barry barish received the Nobel Prize the ligo discoveries prove that black holes can merge one way they can grow bigger quickly more and more evidence of these merging black holes tells us there are a lot of these Stellar black holes around that they can find each other and and merge and the discovery opened an entirely new way of observing the universe [Music] we always thought of astronomy as an observational field where we are looking at radiation we are seeing things but this is not radiation this is something much more fundamental these are sort of fundamental Tremors in space-time itself we can now hear the universe [Applause] for the first time astronomers have simultaneously seen and heard a cosmic event in August 2017 ligo detected gravitational waves from a collision of two neutron stars black holes are empty space but neutron stars are dense dead stars that can crash together and light up the skies when telescopes and satellites around the globe pointed in the direction of the sound the world saw fireworks and an explosive collision and Afterglow possibly the Collision resulted in the creation of a new black hole [Music] but unless we observed the formation of a black hole there is much we will never know because so much about black holes is irretrievably out of our reach we can never know where they came from what's inside or their history but we can imagine their future the number of black holes in the universe is increasing and they're getting bigger Stars collapse black holes feed and merge new ones form could it be that one day everything will end up inside them and they will rule the universe Untold trillions upon trillions of years after this happens and the last bits of matter cross their event Horizons black holes themselves May radiate away and vanish from this reality [Music] their Mysteries are many and we're just starting to unlock the secrets of these strange powerful places but one thing is certain black holes will continue to Intrigue us tantalize us and challenge both our science and our imaginations thank you [Music] [Music] thank you [Music] thank you [Music] [Music]

Channel: NOVA PBS Official

Views: 907,472

Keywords: nova, pbs, novapbs

Id: 1LYSfpKog4w

Length: 113min 4sec (6784 seconds)

Published: Fri Aug 25 2023