A Science Odyssey: Mysteries of the Universe - Documentary

[Music] January 1910 Halley's Comet is about to return and this time say scientists the earth will pass through its ghostly tail with each passing week this mysterious visitor becomes an ever bigger story comets have long been linked in people's minds to catastrophes of one kind or another plagues wars the death of kings even some scientists are concerned a French astronomer I'll read a large warns of dramatic changes in weather and indeed just weeks before Halley's arrival Paris is staggered by

the worst flooding it has seen in decades the Lord's colleague Camille Flammarion as an even graver worry [Music] he fears gases in the comet's tail might combine with nitrogen in the Earth's atmosphere to produce enough nitrous oxide or laughing gas - cause contagious gaiety paroxysms of the light and in the end widespread madness and death in 1910 comets are almost as mystifying as there were when 17th century British astronomer Edmund Halley realized that one in particular returns to the cen

ter of our solar system every 76 years as Halley's namesake approaches the excitement anxiety and business opportunities go [Music] but then when it has come and gone it is science not superstition that claims the day [Music] using newly developed tools scientists gather photographic and spectrographic evidence that proves the comet's tail is too diffused to affect our atmosphere and that it's icy heart is but a tiny fraction of the visible hole as the 20th century dogs there's a growing sense t

hat the mysteries of our universe aren't as far beyond our grasp as we once believed [Music] [Music] in my grandfather's time at the turn of the century the night sky is the greatest show out it plays week after week even on Sundays assuming the weather holds part of its power is its infinite mystery no one knows where stars come from or why they shine few believe we will ever understand what the universe is made of what the true nature of matter really is but then within a few years all hell br

eaks loose there are revolutions in astronomy and physics and long cherished ideas are shattered about the nature of the universe of space and time and even reality itself the only thing that remains the same is the glory of the view from the moment the telescope is invented it's our window on the universe [Music] in the 18th and 19th centuries ever larger and more elaborate telescopes reveal ever more stars [Music] by the end of the 19th century telescopes are so large and revealed so many star

s astronomers are working overtime just to catalog them there seems little need to build even bigger instruments if all they could do is find more stars to catalogue but George Ellery Hale disagrees he's passionately convinced a big enough telescope will change astronomy in ways it's impossible to anticipate and he's determined to make that happen [Music] that passion brings him to Mount Wilson in Southern California where the air is almost always free of turbulence and clouds it's the perfect s

pot for an observatory with funds from the likes of steel tycoon and philanthropist Andrew Carnegie Hale sets out in 1908 to build on Mount Wilson the world's largest telescope the instrument he envisions will be almost twice the size of any then in use it will collect and focus lights with a mirror 100 inches wide [Music] Hales enthusiasm is infectious and persuasive it also masks the enormity of the technological challenge he's undertaking nobody is pouring glass mulling glass the size that's

going to be necessary nobody is creating the kinds of beams and girders in the superstructure that's going to be necessary these things weigh hundreds of tons thousands of tons you also have the difficulty that they're located on mountaintops you have to build the roads you have to build the living quarters for the astronomers you have to have machine shops on-site it just goes on and on and on these are almost kind of technological kingdoms in their own right and they've never been designed on

this scale before things seemed to go wrong from the start the mirror has to be the largest solid piece of glass ever made a French glass maker pours enough green glass for ten thousand champagne bottles into a huge mold and then packs the whole thing in manure to slowly cool it unfortunately it comes out flawed twice more they try at each time the giant disks crack as they cool lacking the money to try again hail orders his opticians to grind the first in the hope its flaws aren't fatal it take

s four years of grinding and polishing to finish the mirror and even longer to build the rest of the telescope at its dome hundreds of tons of steel and concrete are hauled up the mountain Road at a cautious 10 miles per hour even at that speed accidents happen [Music] the steel sections of the telescope itself are built at an East Coast shipyard some are so big they must be shipped by boat to California world war 1 has broken out and German submarines are a constant threat long prone to bouts o

f depression Hales worries about the project begin to affect his health later on he admitted that he had been visited by a companion sort of described as a little green elf who might come to his bed or sit on his shoulder perhaps to give him advice about how to run his life how to raise money who to talk to it's it's hard to say the elf perhaps helped him work out some of this stress whatever it is that carries Hale through on November 2nd 1917 the 100-inch telescope is finished [Music] it's 100

tons of iron and steel move with the precision of a fine watch [Music] it's 9,000 pound mirror and detective candle 5,000 miles away [Music] what Hale has built is one of the marvels of the 20th century it will rain for decades as the best telescope in the world and proved beyond doubt the worth of big telescopes [Music] to spend a night here is the dream of astronomers the world over you would open the dome a kind of rolling like thunder you are alone on the mountain with the telescope it's ju

st you in the universe are you and God so to speak you'd sit at the platform at the telescope guiding making very fine adjustments on this magnificent instrument with a little hand paddle with your eye staring down unto the illuminated crosshairs and work there 8 10 12 hours often times it was extremely cold in winter they wore heavy coats sometimes they were bare skin or sheepskin coats you could literally have your tears freeze to the eyepiece and they wanted hot coffee but Hale wouldn't allow

it he thought it was poisonous to the system coffee isn't all that Hale keeps off the mountain top in the 1920s I would not have been allowed to work up here in fact I wouldn't have been welcome even as a wife or a visitor of any of the scientists Hale in his days at Yerkes had found that the wives of some of the astronomers became a distraction to their monastic scholarly studies and so they were essentially banned from the mountaintop ironically without the contribution made by a woman the fi

rst great discovery made with the 100-inch might not have been possible the closest a woman could get to the field was at the time at the Harvard College Observatory where major data collecting projects were in progress women were hired on to help to analyze the data to do all the menial tasks that were below the duties of the men Henrietta Leavitt is one of a dozen women who studied tens of thousands of photographic plates taken by men at distant observatories Levitz task is to examine plates t

aken at different times and look for stars that vary in brightness she notices a pattern in one class of stars called Cepheid x' and realizes the time it takes them to reach their maximum brightness can be used to determine how far away they are it's a landmark discovery before Leavitt astronomers couldn't calculate the distance to any but the closest stars what Henrietta Leavitt did was provide one of the first and still to this day one of the most fundamental yardsticks in the universe it is t

he measure by which all distances are determined without that we'd be clueless [Music] all the astronomers George Hale brings to Mount Wilson will at some point in their careers make use of Levites celestial yardstick but there's one for whom it will have special significance Edwin Hubble a star athlete in college Hubble had won a Rhodes Scholarship and studied law at Oxford University in England upon returning home however he decides against becoming a lawyer and heads off to graduate school to

take seriously a fascination with the Stars that he has felt since childhood when Hubble arrives at Mount Wilson in 1919 he's a smart but arrogant 29 year old there was taken pains to adopt what he sees as the proper image of an astronomer what he tries to do is to create this portrait of himself as a kind of natural-born patrician he tries to lose his Missouri roots because I think he's embarrassed about those things he sees the English gentleman as being the prototype of what he wants to beco

me he wears English tweets he wears knickers which have gone out of fashion except on the golf course he smokes a pipe he spoke with an effective British accent he had dueling scars which were said to be self-inflicted but when whispered among the staff [Music] he loves being separate and apart from his fellow human beings and he plays that to the hill in time most of Hubble's personality quirks are overlooked because he's an excellent astronomer with a gift for asking the right questions Hubble

wants to unlock the secrets of the nebulae faint fuzzy smears of light that have puzzled astronomers for a thousand years even with Hales magnificent 100-inch their true nature eludes him for four long years [Music] finally in October of 1923 while photographing one of the spiral arms of the great nebula in Andromeda Hubble catches a break he took a 40 minute photographic plate and developed it the next day and looked at it and thought he saw what was then known as a nova that was another hot t

opic that is what were nove what were stars that brightened unexpectedly so his curiosity piqued he decided the next night which was a better night to take another exposure and took a deeper photographic plate this plate has what he believes are three novi he had an even greater surprise awaits him well when he got down to the mountain the next day and he began to compare the plates with those that have been taken earlier he discovered that one of the three novi was not in fact a nova but it was

a Cepheid and it's a Eureka moment he writes in capital letters on the slide itself var exclamation point for variable star Hubble knows instantly thanks to Henrietta Levitz discovery about Cepheid x' that this star and the system it's a part of must be very far away and the universe must be far larger than anyone had dreamed Yama's been a good moment for him what he found was that the distance to m31 the Andromeda galaxy one of turns out our nearest neighbors is about two million light-years s

o people have been talking about the scale of our galaxy 10,000 20,000 30,000 maybe a hundred thousand light-years what this meant was that m31 and all those other galaxies were not part of our system they were themselves big systems equal to the Milky Way there are in fact billions of galaxies each one containing hundreds of billions of stars Hubble's discovery of the stunning size of the universe and the multitude of stars and star systems that can be found within it changes forever our pictur

e of the cosmos [Music] that discovery alone would have made Hubble one of the great astronomer x' of the century but he continues to study distant galaxies and makes an even greater discovery for five years he gathers data on the movements of galaxies recording where they're headed and how fast if a galaxy is moving away its light is stretched the interval between wave crests gets longer the light appears redder the faster is moving the redder the light if a galaxy is moving closer the light is

compressed and appears bluer after many years Hubble could sit down and look at this great quantity of information and he plotted a chart he plotted for the nebulae the motions against the distances and he found something truly amazing a straight line he found that the distance of a galaxy is proportional to its velocity so as you go twice as far out turns out the velocities twice as big you know three times as far out the velocities three times as big we live in a world a big world and univers

e where everything's rushing apart and it's happening in a way we call Hubble's law where the velocity is proportional to the distance an expanding universe how could that be when the whole history of human thought assumed just took for granted that the universe is this fixed thing and how could it change the universe is everything how could it have an evolutionary path because if you had an expanding universe that might mean it had a beginning it might mean it'll end this is a discovery for the

ages [Music] before Edwin Hubble's discovery even the great physicist Albert Einstein assumed that the universe is fixed at eternal his original equations for general relativity had predicted a changing cosmos but Einstein was unable to believe his own theory so he added what he called a cosmological constant to bring the universe to rest years later in 1931 Einstein travels to Mount Wilson to meet Hubble while there I stand éclairs that his cosmological constant is the greatest blunder of his

scientific career of course by this time Einstein can afford to admit to a mistake or two he's already renowned as one of history's greatest scientists the man who redefines gravity space and even time at the age of 22 at the turn of the century Albert Einstein is living in Zurich and facing an uncertain future he dreams of becoming a professor of physics but he can't get a job he has alienated most of his college teachers and they won't give him the recommendations he needs in early 1902 he mov

es to Bern he's tired of scraping by with what he can earn giving private lessons and a friend's father has offered to help him get a job there it's with the Swiss Patent Office he's a technical clerk third class reviewing applications for patents on new inventions Einstein was a perfect fit for his patent work and those patents that he considered were in my view absolutely formative of his scientific style he'd sit down every day with stacks of documents and his job was to strip away all the co

mplications to take a patent like this and figure out did this violate the basic laws of physics what was it central idea was it that central idea knew or was it something that had been known and those sorts of decisions which he made every day looking at these new devices shaped his sense of how to strip down a physical problem down to its absolute essentials what are the principles it's this same approach that compels Einstein to reexamine fundamental assumptions of classical physics including

ideas about space and time that seemed to everyone else inescapable in the early 20th century everyone from physicists to sports fans takes for granted that a mile is a mile no matter where the race is run that the runner who finishes in four and a half minutes is faster than the one who finishes in five [Applause] common sense tells us that time and space are the same everywhere and for everyone indeed that was Isaac Newton starting point when he wrote down his laws of motion and gravity in th

e 17th century laws that seemed to explain everything from the flight of an arrow to the orbits of planets but Einstein is willing where others are not to question everything even our common sense view of the universe all I have tried to do in my life is ask a few questions could God have created the universe any other way or had he no choice and how would I have made the universe if I had such ants Einstein is driven to ask such questions by a problem he sees with the traditional description of

light he knew from Maxwell's equations from the great classical physics that had preceded him that light could be understood as a wave and that every time you saw a wave of light it was always traveling by you at some enormous ly fast speed like 186,000 miles a second so we were always in the position of somebody say standing on the beach watching a train of waves go by and with any kind of wave that you've ever seen Reinstein had ever seen you could always catch up with it if you went fast eno

ugh so you had a bunch of waves going down a canal and you've got on your horse and rode alongside it you'd see the wave just frozen as if as if it was not moving because you'd be moving with it and Einsteins thought to himself is this what if I caught up to a light wave what if I went as fast as light was going would I see it still the way the horseman sees the waves in the canal if he catches up to it and then he thought to himself well that would be such a strange sight it doesn't correspond

to anything anyone's ever seen a still wave of light Einstein is convinced that light wouldn't be light if you could catch up to it but in classical physics you can catch up to any wave and light his wave how could it be that there was a wave moving along that you couldn't catch up to he didn't know how to solve the problem he didn't even know how to articulate the problem fully but there was something wrong [Music] children who wonder about things like light time and space are satisfied with th

e stock answers and never gives them another sword as adults but because I was a late developer I first pondered such simple questions as an adult and so told them more deeply and tenaciously than any child would do [Music] in order to simplify the problem he sees with light Einstein uses a series of thought experiments that take place only in his imagination like a journey on a train [Music] from James Clark and Maxwell's equations we know that the light reflected from my face traveling toward

this mirror must move at 186,000 miles per second okay Einstein said but what if the train were moving at the speed of light one possibility is the train catches up to the light waves so they never reached a mirror but Einstein is convinced this can't happen light can't stand still and what does it mean if I do see my reflection in the mirror well from my point of view everything is just fine but for the person standing outside of the Train there's a problem that person sees the train moving by

at 186,000 miles per second and therefore the light reflected from my face traveling toward the mirror must be traveling at twice that rate or 372,000 miles per second three hundred seventy two thousand miles per second is the speed of light added to the speed of the train carrying the light physicists have added speeds this way since the days of Galileo but Einstein concludes this simple adding of velocities is wrong because the speed of light never changes is always 186,000 miles per second ev

en if its source is in motion whether on or off the train you have to get the same measurement for the speed of light the stunning consequence of this is that someone off the train measures rulers on the train as short and clocks on the train as running slow in a flash of brilliance aya Stein proposes that distance and time are not absolute that a foot and a second mission on the train are not the same as a foot in the second measured off distance and time are relative fortunately this phenomeno

n is only noticeable close to the speed of light imagine yourself alongside early twentieth century science fiction swashbuckler Flash Gordon when not fighting the bad guys we're trying to escape from some monster your dashing around the galaxy at incredible speeds while you are your clock and those back on earth are running at different speeds assuming even gone for the better part of a year when you get back everyone you knew would have been dead thousands of years it's the ultimate example of

relative time but Einstein isn't finished quite yet he still has to conjure up the most famous equation of the century e equals MC squared Einstein realized that not only does time slowed down the faster you go he also realized that when objects move they get heavier as they move it was a curiosity why should objects get heavier as they move and then he suddenly realized that the reason why objects get heavier as they move is because the energy of motion is being converted into mass now think a

bout that for a moment the energy of motion is being converted into mass this means that energy is turning into mass and mass is turning into energy and Einstein quickly wrote down it's only one step quickly wrote down the equation that relates energy to matter and it is exactly e equals MC squared Einstein's theory of space and time is called special relativity physicists are intrigued but little changes in Einsteins life with a growing family to support he remains at the Patent Office and move

s on to another even greater intellectual challenge special relativity applies to objects moving at constant speed but most movement involves acceleration speeding up or slowing down so Einstein sets out to extend relativity to cover accelerated motion it turns out to be one of the hardest problems any scientist has ever taken on Einstein struggles with it for ten years now most of us physicists will be grappled with a problem that we can't understand we give up and say God is malicious he's a n

asty God he's giving his problems that no human can understand my ins I didn't have that philosophy at all he didn't say that God was malicious teasing humans with problems that were beyond human Ken he said God is subtle that only if we are dare to penetrate penetrate into the essence of things then we would find the answer to get to the essence of accelerated motion Einstein once again turns to a thought experiment imagine this elevator were located in deep space and uniformly accelerating upw

ard with no windows and no connection to the outside world ayan Stein said it would be impossible for us to determine whether or not we're moving but I you might say I feel the pressure on my feet but his response to that would be but how do you determine whether that pressure is caused by the elevator moving upward through space with uniform acceleration or by the elevator simply sitting on the surface of the earth and you're feeling the effects of gravity the fact that you can't tell the diffe

rence says Einstein means acceleration and gravity must somehow be the same he concludes after a series of incredibly complex calculations that this is only possible if space and time are curved according to Einstein's theory of general relativity the curvature of space is caused by the presence of massive objects Newton had it right that a body in motion tends to stay in motion in a straight line the shortest distance between two points but in curved space the shortest distance between two poin

ts is a curved line an object experiences acceleration around the curve as gravity the Earth orbits the Sun not because of a mysterious force but because the Sun curves the space around it the earth is simply traveling the shortest path through curved space [Music] Einstein's theory of general relativity perfectly describes the motions of planets stars and galaxies both in space and in time suddenly physics could say something about the fate of the universe it could ask questions about whether t

he universe as a whole had a certain curvature whether it would come back in on itself whether it would expand out forever general relativity had a scope as infinite as the universe the world is not the same place once you understand these theories space and time are somehow the same thing that's very different from my experience as I would go through life and I can never go back to looking at things the way they were before I understood this theory [Music] in 1921 Albert Einstein has awarded th

e Nobel Prize for Physics but it isn't for his work on relativity apparently that's too weird for the awards committee to accept instead in Stein is honored for other contributions including a paper on the nature of light this paper ultimately leads to a second revolution in physics only this time it's too weird for Einstein himself to accept it's called quantum mechanics quantum mechanics comes out of the struggle to understand the structure of atoms what physicists in the early 20th century le

arn is that in the world of the very small the seemingly impossible is commonplace things don't exist until someone looks at them we're unable to say exactly what path something takes to get from point A to point B uncertainty and chance are woven into the very fabric of existence one of the key figures in the quantum revolution is a young Dane with a tendency to mumble he's the scientist on the right his name is Niels Bohr and from childhood it's physics that consumes him once while playing goa

lie in an important soccer game he starts scribbling equations on a goalpost only the screams on ardent fan snap him out of reverie in time to stop an opposing players potential goal at school he's an excellent student though he seems to have a serious phobia about writing as a graduate student he dictates his entire doctoral dissertation to his mother causing a family fight when his father insists that the budding PhD not to write for himself he never does after his marriage his wife gets the j

ob in 1912 shortly after receiving his doctorate Bohr travels to England he comes to Ernest Rutherford's laboratory just one year after Rutherford makes a startling discovery about atoms atoms had been seen as amorphous blobs of positive charge studded throughout with negative electrons in fact Rutherford says they're more like little planetary systems all the positive charge and virtually all the mass is concentrated in a tiny nucleus around which the electrons orbit like planets around the Sun

this is the courtyard at Cambridge University where Rutherford began and ended his scientific career imagine an atom this size if we think of that being the size of an atom then the size of the nucleus would only be one millimeter in diameter that's a bit smaller than this little grain of sand that I've got in my hand here none of us what means these items are essentially empty space now how can we reconcile that with the fact that matter is matter and my hands don't go through one another well

that's crazy because if it's mostly empty space they should pass right through one another but what we understand now is in fact that the reason my hands don't go through another is that while the space is empty what it's filled with is really electric fields when the electrons come within a very small distance of each other they begin to repel each other so we have the illusion that things are solid when actually we have this tremendous vacuum given by the fact that the atom is basically empty

now this means that I'm not really sitting in this chair at all the Animus of my body are about one angstrom hovering over the atoms of this chair Rutherford's conception of the atom is a breakthrough but almost immediately he finds a paradox at the heart of it see the problem Martha if you've got a nucleus with a positive charge and electrons in orbit about it then we know that the electron should very rapidly orbit into the nucleus it should do it in a fraction of a second that's a very secur

e prediction of classical physics that's catastrophic what it's telling you is that atoms cannot exist it means that you and I would not exist the atoms would have no way of supporting themselves with large volumes that they have where Niels Bohr arrives in Manchester Rutherford is ready to abandon his model of the atom but Bohr shies away to save it he was so excited he canceled his honeymoon he had to delay his wedding cancel the honeymoon and his poor fiancee instead of going on a luxurious h

oneymoon had to take dictation as her husband dictated one of the greatest masterpieces in physics because he himself could not get himself to write down the paper what do you oppose the laws that you would not all allow the electrons to move in any orbit about the nucleus as you could according to classical theory but only to occupy certain very well-defined orbits about the nucleus there'll be no but here an orbit here an orbit here but there would not exist all of its between these there's no

thing in between in between exist nothing and that's very non-newtonian if you take the earth and you would you could move the earth a little bit closer to the Sun no problem we'd have a different orbit would be stable we'd have a different time to go around the Sun no problem that you cannot do with an electron around a nucleus you cannot just change the orbit by a little bit you have to change it by so to speak a lot poor's idea that electrons can have only certain orbits draws inspiration fro

m other new theories that suggest heat and light come in units that can't be divided called quanta but applying this quantum idea to matter is practically sacrilegious in fact most physicists disapprove of Bohr's theory whenever they meet they scoff at the idea that an electron can be in some places but not others that matter comes in some sizes but not others if it's not nonsense at least it doesn't make sense this is just a cheap excuse for not knowing what's going on the assumptions are too b

old to fantastic that can't be right in time two camps emerged a group around Bohr which believes in his so-called quantum theory of matter and those who cling to the classical view no less than the true picture of nature is at stake in 1926 Verner Heisenberg 25 year old German physicist comes up with a mathematical description of atoms that goes a long way toward legitimizing Bohr's view classical physicists remain unconvinced Heisenberg's mathematical matrices are too complex and the mysteriou

s comings and goings of electrons are just too hard to imagine within a year an Austrian named Aaron Schrodinger offers an alternative short enger' had his beautiful theory of the electron as a wave it was smeared out over space and time it wasn't a particle at all physicists loved this idea we had a physical picture we could look inside the atom physicists knew how to calculate with waves they calculated waves as an undergraduate in college they knew how waves went around in formed orbits so th

e appeal of the short enger' picture was that it was pictoral it was almost Newtonian it was continuous none of this quantum business and you could calculate with it so which is it is mattr made up of waves or particles they seem to be complete opposites waves can pass through one another sometimes cancelling each other sometimes making even bigger waves put particles on the other hand bounce smash exert force when they meet they can't cancel each other out so these two pictures clashed with eac

h other and they debated and had arguments and they yelled and screamed at each other in fact one day Heisenberg was so worried that he simply came down with hives and and hay fever and tremendous case of allergies worrying about whether or not the rival picture was correct in 1926 Bohr and Heisenberg invite Schrodinger to Bohr's new Institute in Copenhagen to try and work out their differences Heisenberg writes about the visit though Bohr was an unusually considered and obliging person he was a

ble in such a discussion to insist fanatically and risk almost terrifying relentlessness on complete clarity in all arguments he would not give up even after hours of struggling until Schrodinger had admitted that his interpretation was insufficient every attempt from Freudian aside to get round this bitter result was slowly refuted point by point in infinitely laborious discussions boar's wife nurses Schrodinger when he falls ill from exhaustion she brings him tea and cake even as her husband s

its on the edge of the bed continuing the argument still Schrodinger clings to his classical view wearily noting at one point if one has to go on with these damn quantum jumps and I'm sorry I ever started to work on atomic theory the essence of the Bohr Heisenberg picture was that the electron was a particle however there was a certain amount of uncertainty with regards to where the particle was now one day Heisenberg was so paralyzed worrying about all these problems that he took a walk in the

park outside his Institute there's a famous park and late at night he walked through the park wondering how can it be how can it be that you don't quite know where the electron is and then in a flash he understood because to understand where an electron is you have to look at it to look at it you have to shine a light on it but when he's trying to light on it that disturbs where the electron is so the very fact of observing an object changes its location therefore he realized that uncertainty is

an essential part of his picture Heisenberg calls his insights the uncertainty principle in a clear mathematical way it says the more you know about a particles position the less you can know about its speed and direction the opposite is also true the more you know about a particle speed and direction the less you can know about where it is at any given time and when he finally had that idea he realized that he could merge the Schrodinger picture with the Bohr Heisenberg picture to give us the

modern-day theory of the quantum principle in other words the electron is a point particle but you don't know quite where it is and the probability of finding it at any given point is given by a wave the short integer wave so we now have this beautiful synthesis of waves and particles Heisenberg's principle is indeed is very very non-intuitive frankly speaking I call it bizarre but you can see it at work suppose I have a laser beam here and I use laser beam because that's right but I could use a

ny other light for that matter and I make here an opening a slit a vertical slit and here goes the laser beam right through the slit light goes on it goes on and here I project this onto this wall or screen projection screen and what do I see well you see exactly what you predict you see here this laser spots from this beam but now I'm going to make this vertical slit narrower and narrower and narrower what now are you going to see well you going to see exactly what you predict you're going to c

ut off the edges of the circle and the spot gets narrower and narrower and narrower but now you come to the point that this narrow slit say is only one hundredth of an inch wide and now Heisenberg's principle comes in because now you know so precisely in the horizontal direction where the light is that as it emerges from this slit the direction of the light is no longer determined according to Heisenberg's principle and so now what you're going to see it's going to spread out in the horizontal p

lane and therefore what you're going to see on this projection screen it's going to get wider extremely non-intuitive because what am i doing I'm making the slit narrower and narrower and narrower and narrower and what do you see ultimately that the beam horizontally becomes wider and wider and wider and wider and wider and wider wider now that is very non-intuitive but it's the way the world works according to the quantum theory even the most bizarre events have a probability of taking place th

ere's a certain probability that I will dissolve and simply ream aterial eyes on the other side of that brick wall now you may say to yourself well well that's impossible we've never seen anyone dissolve and rematerialize on the other side of brick walls but we actually give this problem to our graduate students to our PhD candidates we ask them to calculate using the quantum theory what is the probability that you will find yourself on the other side of a brick wall now to tell you the truth yo

u would have to wait longer than the lifetime of the universe for such an event to take place so you don't have to worry your atoms are not going to dissolve and you're not going to ream aterial eyes on the other side of brick walls but there is a probability you can calculate for that event happening and then you can actually sell the question do I understand it I don't even know what that means understanding I have problems with that physics describes things describes phenomenon and as long as

it is predictable as long as that formalism applied in a certain situation gives you the right answer who cares who cares what the meaning is of understanding I think I leave it up to philosophers and I think they'll don't they don't have a clue either of course but they there are some physicists who refuse to accept that quantum mechanics represents the full story of the subatomic world the most famous is Albert Einstein quantum mechanics is very worthy of regard but an inner voice tells me th

at this is not the to Jacob as a seer Lee yields a lot but it hardly brings us any closer to the secret of the old one in any case I am convinced that he doesn't soul dies he couldn't believe that there were big patches of the world about which we could not know and his idea from early on in his life all the way to the end of his life was that there ought to be a set of equations deterministic causal ordered formulated in such a way that they could tell us everything about a future in terms of e

verything about the present and quantum mechanics wouldn't allow it he couldn't stand that idea [Music] the world's greatest physicists gather in Brussels in 1927 Einstein challenges Bohr and the idea that uncertainty rules the world Werner Heisenberg writes in his diary we all stayed at the same hotel the discussion usually started at breakfast was Einstein serving us up an imaginary experiment by which he thought he had definitely refuted the uncertainty principle in the course of the day we w

ould have discussions on the matter and as a rule by suppertime we would have reached the point where Niels Bohr could prove to Anglin that even his latest experiment failed to shake the uncertainty principle Einstein would look a bit worried but by next morning he was ready with a new imaginary experiment more complicated than the last one of Einstein's challenges is so clever it has Bohr deeply concerned for the future of quantum mechanics physicist Leon Rosenfeld writes boy did not see the so

lution I shall never forget the sight of the two antagonists leaving the hall Einstein a tall majestic figure walking quietly with a somewhat ironic smile and Bohr trotting near him very excited during the whole evening Bohr was extremely unhappy going from one scientist to another trying to persuade them that it couldn't be true that it would be the end of physics if Einstein were right Bohr spends a sleepless night in his hotel room before he discovers a flaw in Einstein's argument ironically

it involves a subtle application of Einstein's own theory of relativity Bohr and Einstein are an astonishing pair in many ways they they loved each other they loved talking to each other they loved engaging with each other's ideas and yet they wanted such utterly different things from physics that they never really could see eye-to-eye God does not throw dice was Einsteins unshakable principle one that he would not allow anybody to challenge to which Bohr could only counter nor is it our busines

s to prescribe to God how he should run the world [Music] Einstein and Bohr have their last battle about quantum mechanics in 1933 by this time both relativity and quantum theory are almost universally accepted by physicists as the most powerful ideas they have for explaining the world now attention shifts to another challenge figuring out what goes on inside the atom physicists want to know what holds the nucleus together they want to know if protons electrons and the newly discovered neutrons

make up everything in the universe what if these particles are made up of something even more fundamental in the process what begins as an intellectual quest turns out to have explosive consequences in the early 1930s Albert Einstein emigrates to America to escape the rising tide of fascism and anti-semitism in Germany [Music] before the decade ends many of Europe's finest scientists are forced to make the same journey among the last to leave is niels bohr he arrives in the United States in 1939

bringing with him stunning news [Music] in Hitler's Germany two scientists have split an atom of uranium releasing in that moment some of the tremendous energy bound up in matter using simple equipment widely available they produced the first evidence from a controlled experiment of Einstein's famous equation e equals mc-squared I was in Berkeley and people had gone to the meeting in Washington where they were brought his news and they called up and said gosh this is amazing can you do it and i

n a day or two two or three people had done it I could see the big spikes sufficient on the oscilloscope screen and by the end of the month everybody knew this was going to be your timing device at a super-secret facility deep in New Mexico scrubland the US Army assembles a team of American and transplanted European physicists the greatest collection of scientific talent the world has ever seen their challenge create an atomic bomb before the enemy we were galvanized by the no shoe that the Germ

ans were ahead as they expend a lot of money they were very good they're just discovered in Germany they had able people actually didn't realize that they had lost so much by destroying the community as they had done it was lucky Americans have the talent and practically unlimited resources in less than five years two billion dollars creates a nuclear project the size of the US auto industry yet until the very end no one can say for sure the product of all this effort will work the basic physics

was known the quantum principle was known relativity e equals MC squared was known the chain reaction was known but it was not known how to put it all together so these physicists some of the brightest minds of the world were concentrated at Los Alamos not to discover new physics because that was already done by the Bohr's and by the Einsteins they were assembled to see whether or not it would actually work when I first brought the plutonium sphere in contact with a high explosive I was quite s

cared about a high explosive and Roger Warner who was in charge of that particular assembly he was calm and he said don't worry about that you can't run very far in a millisecond anyhow so you'll never know what happens if it goes off wrongly it was a new world everyone could see that maybe they'll be doing end of the war that was very good but who knows was gonna come after that we didn't know I should have no more than we did but we didn't it was a fantastic experience of taking theory theorie

s that were equations and building something of enormous power the power of the Sun but just like the opening of Pandora's box perhaps humanity was not ready for a cosmic fire perhaps humanity was not mature enough to handle the power of the Sun now being placed on the earth [Music] [Music] there's a universe up there that we can't see with our eyes even if we have something a thousand times larger than this we have to turn to a different kind of telescope well without lenses or mirrors or any o

f the other things astronomers have relied upon for centuries this invisible universe has to be seen with telescopes that use radio waves x-rays infrared rays or gamma rays everything in the universe gives off radiation of some kind for example the glaze on this teacup emits gamma waves imagine that it is a galaxy and this geiger multi to a crude ray telescope in the second half of the 20th century astronomers start exploring the heavens with instruments that are sensitive to a number of differe

nt forms of radiation when they do it's like lifting a veil from the face of the universe one of the most surprising discoveries of post-war astronomy is made with this device built outside Cambridge England it may look like four and a half acres of laundry line but it's really a radio telescope as the Earth rotates miles of antenna wire receive radio signals day and night when it goes into operation in 1967 Jocelyn Bell gets the task of running it within months the young graduate student notice

s something she's never seen before it's a funny blip on one of the long rolls of chart paper used to record what the telescope sees the first few times I saw it I just put a question mark by it and passed on but I think the human brain stores problems I think mine does anyway things that it can't resolve things that I can't cope with because this curious little signal occupied about a quarter of an inch in 400-foot and yet somehow my brain stored that way way back somewhere but it stored it and

after it had dealt with this problem a couple of times and it faced at the third time it said something like this before she immediately calls her thesis advisor radio astronomer Anthony Hewish he's intrigued but cautions the signal was probably man-made Bell goes back to her charts and figures out when the signal should come again she sets her instruments to record a more detailed image and discovers the signal is a string of pulses exactly one and a third seconds apart never before has a tele

scope of any kind found something like this it's a complete mystery heavenly bodies don't just pulse on and off look at the Sun the Sun doing this look at the moon it says soon moon doing this look at all the stars in the sky look at them would you naked I have you ever seen one go nothing right and one way out it didn't explain everything but one way out was to say well maybe it's little green men sending a signal to us [Music] I think they were totally shocked shell-shocked that this possibili

ty existed they realize it would be the discovery of the century if we get in touch somehow receive signals from civilizations what do you do if you have really picked up signals from another civilization do you tell the president the press or the Pope first before they can tell anyone anything bill finds what could be a second signal she heads out to the antenna on a cold November night to check it out I came out on my scooter slithering all over the place on the ice and when I got here the mac

hinery wasn't working properly because of the cold but I flicked switches I kicked it I cursed as I breathed hot air on it and I got it to work for five minutes and it was the right five minutes and it was the right setting so as it was looking at the right bit of sky and then came poop poop poop poop very like the first lot but not totally the same a little bit different one and a quarter seconds I said at one over third and that settles the little green man question because it's so unlikely th

ere'll be to lots of little green men opposite sides of the sky both deciding to signal to an inconspicuous planet and using a not very intelligent way of doing it also so it had to be something stellar the news of bells pulsing stars spreads rapidly through the astrophysics community it is clearly an important discovery what they are and how they pulse is a real mystery so if you take a large object collapsing it rotates enough and you go back to the old argument perhaps it's a whiteboard perha

ps the residues finally a physicist connects what Bell has found with an old theory about the death throes of stars this theory long assumed to be untestable predicts that when a large enough star runs out of nuclear fuel it will collapse and crush the atoms within it what's left is like nothing else in the universe an incredibly dense object made almost entirely of neutrons every open space that you can think of between electrons in the atoms is squeezed out and it becomes one huge nucleus and

the electrons are pushed into the protons forming neutrons that's why we call them neutron stars a neutron star has typically a radius of about 10 kilometers six miles but the amount of matter in a nucleon star is a little bit more than the total mass the total metal do we have in the Sun a spoonful of this neutron star matter would weigh if you like the word weighing in pounds it's 2 times 10 to the 11 it's a 2 with 11 zeros pounds in one spoonful neutron stars can rotate up to 700 times a seco

nd as they do their powerful magnetic fields ripped through space blasting radio waves outward like a galactic lighthouse it's that beacon that Jocelyn Bell sees with her radio telescope [Music] theory had said that neutron stars are possible but for decades astronomers and physicists clung to the view that they're just too weird to be real bells discovery is dramatic confirmation that the universe is stranger and more fantastic than anything we experience in our corner of the cosmos [Music] the

reality of neutron stars stirs excitement that black holes may also be real they are perhaps the most fantastic and unlikely prediction ever made by physicists World War one had just broken out when Albert Einstein publishes his general theory of relativity among those fighting on the Russian front is a German astronomer and physicist named Karl Schwarzschild with the war raging around him Schwartz child discovers that Einstein's equations predict the existence of a star so unimaginably dense t

hat even light cannot escape it from the battlefield he sends Einstein his calculations just weeks after receiving Einstein's reply Schwarzschild dies on the front lines Einstein marvels at Schwartz tiles work but he never accepts that such a star could really exist as he puts it it just doesn't smell right [Music] through the 1960s most scientists agree with Einstein but the public is completely taken with the idea of a Dark Star in which Escape is impossible where time that space ceased to exi

st [Music] Zen put forward coordinate eight nine zero on visual confirmed that is nothing there Zen use long-range intensifier three guesses if you need them a black hole my god we're falling into a black hole [Music] the existence of a real black hole is almost impossible for physicists to accept yet many have to admit that the process that creates neutron stars should also create black holes when a star has burned up all its nuclear fuel and there is no longer heat that pushes it out that the

core collapses and it can form a neutron star this collapse can be so strong depending upon the original mass of the star that it overshoots and doesn't become a neutron star but become even smaller and then it can become a black hole if you take the earth to give you an example and you take advice if you could make vice and you squeeze the earth the earth has a radius of 6,400 kilometers if you could make the radius 3 centimeters the earth would become a black hole 3 centimeters this big then i

t would automatically further collapse onto itself nothing could stop it and it will become a black hole and you could never lie to could never leave it radio waves could not leave it because they all go with the speed of light [Music] finding something that doesn't give off light or any other kind of radiation is tricky to say the least it's not until the early 70s that astronomers stumble on the first indirect evidence of a black hole the first clue comes when x-ray telescopes reveal an area o

f intense violence and temperature in the constellation Cygnus Paul Verdun is one of many astronomers who begin to focus on this area working with Louise Webster he finds a supergiant star orbiting something they can't see logically the supergiant must be circling a much smaller and denser star one so dense it's gravity is sucking huge amounts of matter from its larger companion only this could produce the intense x-rays other astronomers had detected further measurements reveal the small stars

gravity must be greater than anything discovered before the only explanation is a black hole [Music] there is still no absolute proof that black holes exist but from the 1970s on most scientists have come to accept them as real incredibly strange but real whether there is a neutron star at least you can imagine it has a surface and you can land on that surface and okay it is a mind boggling magnetic field alright but so be it it's there and okay it rotates 700 times per second but a black hole h

as no surface so you can't even talk about a surface that rotates around it doesn't exist and there is no time that you can define that's pretty bizarre that goes beyond totally beyond my imagination I'll be very honest with you but yet it's one of my specialties I measured them I find them can I envision them now current theory holds that there are billions of black holes in the universe including enormous ones at the center of most galaxies [Music] these are so large they must have devoured mi

llions perhaps even billions of stars [Music] but even the birth and growth of black holes are nearly as fantastic as the creation of the universe itself for most of human existence the question of how everything began is one that only religion dared to answer but with Edwin Hubble's discovery that the universe is expanding some scientists begin to believe that they too might have something to offer their reasoning goes something like this if the universe is expanding then in the past it must ha

ve been smaller go far enough back and everything must have been crunched together at a point of infinite density our universe began they suggest when that point exploded creating the expansion we still see today this vision comes to be called the Big Bang theory of creation at the start of the 1960s scientists are equally divided between this Big Bang Theory and a competing notion that the universe is eternal called the steady-state theory but there's no real Parden evidence for either one in f

act almost no one expects the debate will ever be resolved in the early 60s Robert Dicke an astrophysicist at Princeton University comes up with what he thinks is a way to test whether or not the universe started with a big bang he's convinced that it had happened the entire universe should be filled with radiation left from the moment of creation Bob Nikki's reasoning was quite interesting he reasoned that if the universe had gone through this Big Bang phase it must have been very hot and very

dense and there must have been a lot of heat radiation very high temperature and he couldn't find any theoretical way to get rid of this radiation it must still be around it's cooled off because the universe expanded but it must still be around and in the microwave band and where radar works it's a truly amazing possibility 15 billion year old heat transformed by the expansion of space into low-level radio static that permeates every corner of the universe if it's there the only cosmological the

ory that can explain how it got there is the Big Bang Dickie convinces David Wilkinson and another young physicist to build an antenna and search for this cosmic background radiation we weren't in any particular hurry because Bob Dickies idea was so original we weren't too worried about somebody else getting there before we did so we charged ahead rather slowly we had knowing no microwave equipment at all we had to order things new we went down to Arch Street in Philadelphia and dug around in th

e World War two surplus shops to find things that were cheap Bob Dicke is a rather a frugal experimentalist so if we could find it in the junk shop we did that this is the antenna that resulted it's carefully calibrated using super cold helium while Wilkinson is building it to other scientists just 30 miles away are setting up an experiment that seems to have nothing to do with the Big Bang with colleague Arno Penzias Bob Wilson plans to use this microwave antenna to study our galaxy he's unawar

e of Dickies idea in fact he doesn't believe in the Big Bang but prefers a universe with no beginning or end I like the steady-state is philosophically satisfying because there's no end to the universe in the future it goes on forever in the same sort of state that it is and there's no beginning for it either so physicists generally like steady-state because they don't like to have to have a time beyond which they can't know anything Wilson and Penzias are then just getting started on their scie

ntific careers we have no desire to confront a problem as difficult as whether or not the universe had a beginning they just want to make some small contribution to astronomy doing science by ourselves was a great new adventure we've sort of had a chance at Bell Labs to become scientists you know in the real sense and make use of this unique instrument and we really devoted ourselves to it Wilson and Penzias believe the Holmdel antenna will make a great radio telescope because it's designed to r

eject all extraneous signals or noise but for the very first time they use it extraneous noise is exactly what it seems to be picking up every time we started up we saw the same noise level everywhere in the sky we pointed we saw the same noise level it isn't a lot of noise but they fear it's enough to compromise some of their research so they decide to find out what's causing it and get rid of it they check to see if it's there at night they check to see if it's there in different seasons they

check all possible ground-based sources of radio noise they check the antenna itself and tape all its joints they double-check every piece of equipment in the system and the noise is always there with few alternatives left to try they decide to check a real long shot a set of pigeons had started roosting up in the throat of the thing and of course they'd coated it with the same white pigeon droppings that you see on statues and so forth in the city we got a ladder from the carpenters and a coupl

e of push brooms and some scrub brushes and scraped off the difficult ones and swept the whole thing out they check again and realized they could have left the pigeons alone a year of this struggle has left them convinced the antenna is fine the only possibility left and it doesn't make sense is that every corner of the universe is filled with the same noise desperate they begin calling other astronomers for help and one suggests calling Bob Dicke in the phone rang and Bob picked it up and it wa

s two guys from Bell Labs who had a problem which at first didn't seem to have anything to do with us we didn't learn very much on the telephone but they agreed to come out and see what we had done and tell us about what they had in mind he hung up the phone and I'll never forget exactly what he said these are his exact words he said well boys we've been scooped Robert Wilson and Arno Penzias had already heard the echo of the Big Bang their annoying background noise was in fact nothing less than

a whisper from creation itself in the beginning some 15 billion years ago the universe exploded from a single point [Music] less than one minute later it's a million billion miles across though cooling rapidly it still has an average temperature of a billion degrees the universe continues to expand and cool gradually gravity draws together atoms and then clumps of atoms it takes a billion years before stars form and galaxies are created [Music] eventually around some of the stars planets form a

nd on at least one life begins [Music] if everything in the universe began in a single point it's hard not to wonder what it took to go from such ultimate simplicity to all of this many physicists believe that at the beginning of time there was only a single particle governed by a single force from that starting point within a tiny fraction of a second particles like protons and electrons evolved and forces like gravity and magnetism came into being but did the universe have to be like this coul

d have turned out any other way perhaps if we can work back to the moment of creation that an ultimate particle and force we will come to understand why the universe is the way it is and even to express it in what fizzes is called the final theory which its hopes can be captured in a single equation that can fit on a t-shirt this may explain everything when we look at nature we see the complexities the differences among things but scientists tend to look for the connections the simplicity that l

ies at the heart of it all the more you learn about nature the simpler it looks and that's why I think we will find a final theory because although I can imagine things getting infinitely more complicated complication without end I can't imagine simplicity without end the whole progress of physics has been toward and more and more simple description of nature and how simple can things get and simplicity must finally terminate there must be something so simple that we can't imagine anything more

simple but in the years following World War two physicists are stunned to find their dream of ultimate simplicity slipping away experiments meant to reveal simplicity find ever greater complexity California home of the bevatron the BB stands for billions of electron volts world's most powerful atom smashers it's the beginning of the era of big science giant atom smashers are built to accelerate subatomic particles to fantastic speeds and smash them into other atoms each new accelerator built aft

er the war was more powerful than the one that came before each was able to ram particles into each other harder and to show what was happening at a smaller and smaller scale it was just like the telescope's with each new telescope that was built you could see further out into space gather more light resolve objects more precisely with each new accelerator people were able to see deeper into matter more precisely better resolution smaller scale photographs of the tracks of the objects produced i

n these accelerators reveal a multitude of new particles that seemed just as fundamental as the familiar proton Neutron and electron we were literally drowning in subatomic particles one year out of sheer frustration J robert Oppenheimer father of the atomic bomb stated that the physicist who does not discover a new particle that year should win the Nobel Prize in Physics there were hundreds and hundreds of particles which looked just as elementary as the proton it became clear that if elementar

y meant anything either there was something more elementary inside these particles or perhaps they were all elementary a frightening idea among the physicists unhappy with all this complication is a brash young theorist named Murray gell-mann by the age of 25 Gelman is already well-known in the world of physics for his encyclopedic interests and knowledge his quick and creative mind and his frequently abrasive personal style a colleague says of him Murray has no particular talent for physics but

he's so smart he's a great physicist anyway the important thing is first to steep yourself in the problem to look at the puzzle all the pieces of the puzzle by looking for patterns and symmetries Gelman finds a way to organize all the newly discovered particles into families then inspired by a chance encounter during a visit to Columbia University in New York he takes a giant step towards simplicity over lunch a physicist approached him and said isn't it possible that your theories could be exp

lained by postulating three even more fundamental particles well everyone at that table dismissed that idea immediately and they patiently explained to this physicist what was wrong you would have fractionally charged particles an outrageous ridiculous idea because everyone knew that particles were either plus 1 or minus 1 in charge never one-third or two-thirds but over the months that follow yelman grows to love the idea of this deeper level of reality the fact no one's ever seen particles thi

s bizarre he decides isn't his problem in early 1964 Gelman proposes to the world the existence of three new fundamental entities he calls quarks his three quarks could combine in different ways to reproduce the properties of this enormous particles ooh it would simplify organize predict it was a great scientific advance the problem was that no one had ever seen anything that looked like a quark are they actually real object well my experimental friends are making a search for them in all sorts

of places one atomic spectroscopy was friend of mine calls me up sometimes at midnight to report his progress in a search for Forks in seawater most things with curious chemical behavior in the ocean end up by and so now he's grinding a boy stirs physicists were faced with the paradox where were the quarks everywhere we looked we could not find any physical evidence for the quarks and in fact some physicists even began to doubt the correctness of the theory however over the years indirect eviden

ce began to trickle in confirming this theory and now when experimenters take a hard look at the proton they see strong evidence of the quarks inside and also quarks may be real but they're still pretty strange for starters they're so small it's hard to apply to them our normal notions of size physicists describe them as points points come on mean points how can something have a mass and a charge and be a point well it takes a little a few muscles in the mine and haven't been worked down but if

you work on them for a while you can imagine such an object it's a little bit like Allisyn what Nolan remember the Chesser cat sitting on the tree smiling and Alice's noticing that the cat is disappearing in front of her eyes and poof when the cat this appears the smile is left behind you remember that well in a way you can look at that as you take take a cork and it's spinning and it has a spherical if you like and it has mass and charge and spin and all these other properties that we like to m

easure about it but it in front of your eyes it's shrinking and finally it to shrinks to a point leaving behind its spin its charge its mass and if it has a smile if you think of the eye that's smile that's the idea of point particles with quarks physics journey into the heart of matter takes a giant step toward its goal of finding an ultimate particle from which everything is made instead of hundreds of fundamental particles in nature now there are simply three electrons quarks and neutrinos ti

ny particles with almost no mass that rarely interact with the stuff were made of [Music] the search for a single fundamental particle is matched by the search for a single force that governs the behavior of everything this was Albert Einstein's great quest for the last 25 years of his life more than once he thought he had done it only to learn his solution was fatally flawed when Einstein was working on unification he recognized two forces gravity and electromagnetism but today physicists have

to deal with two others the strong force and the weak force the weak force is responsible for many forms of radioactivity the strong force holds our nucleus together the nucleus is full of protons which all have positive charges and if there was nothing to hold them together the electric forces would make them fly apart because equal charges I repelled the strong force prevents that from happening one of the physicists who plays a key role in their quest for unification is Steven Weinberg specia

lty is the two forces within the atomic nucleus the weak and the strong like a lot of other physicists I got started with chemistry around I had a hand-me-down chemistry set that was given to me by an older cousin first I just like to play with the powders and the liquids and make colored smoke and things like that and gradually just reading about it I became aware that what went on inside an atom was something that couldn't be explained in terms of ordinary things that I knew about in everyday

life and I got the feeling there was something strange and wonderful about physics which was the science that governed what goes on inside atoms that feeling about physics stays with Weinberg through college and grad school [Music] in the late 60s he's struggling unsuccessfully to use certain mathematical ideas to make sense of the strong force the one that holds atomic nuclei together and then at a certain point I think when I was driving my car to MIT I realized my goodness this kind of mathem

atical idea although it's a complete loser as far as the strong forces are concerned is just what we need to make a theory of the weak force and to my surprise although certainly not my disappointment what came out at the end was not just a theory of the weak forces but inevitably a unified theory of weak and electromagnetic forces all of a sudden from four fundamental forces we now had three fundamental forces and this changed the entire terrain of theoretical physics in order to test Weinberg'

s theory the European community spends a staggering 150 million dollars to modify and make more powerful its largest particle accelerator the protons are in the machine we're now in the countdown in the subatomic shrapnel created in these collisions lies the evidence that confirms the correctness of the electroweak unification the four fundamental forces are now three but just as three types of particles doesn't satisfy neither does three forces in the mid-1980s work begins on what most physicis

ts believe is the key to getting even closer to the heart of matter it's called the superconducting supercollider or SSC with an underground particle ring 50 miles long it's designed to recreate the conditions of the universe in its first trillion trillion trillionth of a second it was to be a device so large it would enclose towns inside it it was a machine that would require buses to get from one part to another it was a machine that would ship volumes of data equivalent to the entire Library

of Congress out to distant laboratories around the world with amazing frequency the detectors the sites where the actual physics would be conducted would cost a billion dollars apiece and have somewhere near a thousand physicists and probably an equivalent number of technicians at each one but in 1993 after an investment of two billion dollars construction on the SSC is halted years of escalating costs have eroded congressional support the message to scientists is find another way to hunt for th

e ultimate particle and the ultimate force physicists are devastated when the American particle physics community gambled on the SSC they had essentially to shut down program after program in the hopes that they could convince the politicians that by making these sacrifices they should receive the amount of funds necessary to build the superconducting supercollider when this SSC was cancelled they essentially lost everything even still the search for unification goes on in the 1980s theorists pr

opose that at the heart of everything are infinitesimally small vibrating strings string theory quite simply is the most exciting idea to hit physics since the days of Einstein and Bohr it may well be the final theory the one that explains absolutely everything [Music] the pythagorean's believed that music was the language of nature that their harmonies on a violin string which they worked out for the first time in history were the harmonies of the universe and they thought that all around this

surrounding us was music the music of the spheres unfortunately that idea never got anywhere because that couldn't explain the elements now we think that if I have a super powerful microscope and could peer into an electron I would see a vibrating violin string and when that note changes it changes into a quark it changes into gravity it changes into light so in other words our bodies are nothing but collections of strings and the laws governing these strings are the harmonies of the strings and

they are the laws of physics theorists usually imagine strings as incredibly small closed loops more like rubber bands than anything else ordinary matter even space time and energy are nothing more than the vibrations of strings to physicists they are beautiful elegant simple everything they dream about but the mathematics needed to describe them is anything but super symmetric definition of an index and the statement is that the topology of the super space can only be generated by the topology

of the bosonic manifold mathematics or theoretical physicists really is an extra sensory organ I cannot make myself as small as an atom I cannot make myself the size of a proton but with mathematics I have an accurate representation of that and then I can use my mind to actually look at those small things one of the strangest things about string theory is that it only works if there are ten or more dimensions some people say to us but that's not common sensical that violates common sense well w

hy should common sense have anything to do with the universe why should the universe care about your common sense so we physicists are prisoners we are prisoners of experiment prisoners of our mathematics and we simply go where the mathematics go where the experiments take us with string theory they're going way out there using mathematics in a way that physicists have never use mathematics before in ten dimensions we can look at the entire Clifford algebra of the direct matrices they're becomin

g more and more mathematical more and more esoteric unfortunately and most unfortunately evolved further and further removed from experimental verification but in a sense it's the only game in town it's the only hope we have of unifying everything but we are talking about now is understanding all four from mental forces that's the power of this theory we're talking about a theory of the universe will it give me better color television the answer is no it's not going to give you a bigger toaster

it's not going to give you better sliced bread but it will give you is a theory that will affect the core the future course of human civilization your great-great-great grandchildren well one day live to harness the power of the unified field theory no one knows if the string theory is the final theory but if it isn't physicists are sure to keep searching I think it's almost a religious belief that things must somehow very deep down be simple and that we are to some degree blind and don't see th

is simplicity but our searching for it now that's what physics has been doing always very difficult process he's very difficult phenomenon which seemingly are unrelated chaotic through simple descriptions pull them together and unify them and that will go on for a long long time astronomers will also keep trying to solve the mysteries of the universe on a mountain in Arizona one team of scientists is searching the sky for clues to the ultimate fate of the cosmos at this and other telescopes arou

nd the world they're measuring lights from stars halfway across the universe then Bob Kirchner and his colleagues will use those measurements with Einstein's equations to calculate the approximate mass of the entire cosmos this is not easy no supposed to do except just sit there and take it if Krishna finds enough mass it means the universe will one day stop expanding and will collapse back upon itself in what astronomers call the Big Crunch if he finds less than that amount the universe will ex

pand forever into virtual nothingness the actual measuring and so it's very laborious and it's slow and you sit there and it takes all night for these photons to dribble in but the thing that makes it exciting you've been thrilling in a kind of quiet way is that we're after a big question we're really after a question that people been interested in for a long time ever since they could kind of frame the question what is the fate of the universe is it going to last forever how will things end the

se are big questions and we're really on a path that could give us a concrete answer in the context of how we understand the universe today of which of those possibilities is really the right one so that's a lot of fun and it keeps you awake at night [Music] calculating the total mass of the universe will also shed light on what may be the biggest question facing 21st century astronomy the mystery of dark matter that's matter we can't see but we know must be out there because we've measured its

gravitational effect other things we can see [Music] telescopes as disparate as the newly refurbished 100-inch the George Hale built atop Mount Wilson to the Hubble Space Telescope in orbit around the earth we'll all be enlisted in the years to come in the search for clues about dark matter [Music] theorists believe 99% of the mass of the universe is invisible to telescopes if that's the case it's like a modern Copernican revolution Mike Copernicus told us that the earth wasn't the center of the

universe ok then we learned indeed that the Sun was in the center of the universe and our galaxy isn't the center of the universe now we're learning that this dark matter which may be made of stuff which is completely different than anything we see on earth is the dominant stuff of creation that means if you took away you and me and the Stars and everything we see in the universe the real universe would still be there [Music] twentieth century physicists and astronomers have shown us the univer

se more amazing than we ever suspected and a reality stranger than we ever dreamed and the future promises to dazzle us even more as Albert Einstein wrote many years ago the most beautiful thing we can experience is the mysterious it is the source of all true science [Music] a