Lying just beneath everyday reality is a breathtaking world where much of what we perceive about the universe Is wrong? Physicist and best-selling author Brian Greene takes you on a journey that bends the rules of human experience Why don't we ever see events unfold in reverse orders according to the laws of physics? this can happen It's a word that comes to light as we probe the most extreme realms of the cosmos from black holes To the Big Bang to the very heart of matter itself I'm gonna have what he said here our universe may be one of numerous parallel realities the Three-dimensional world may be just an illusion and there's no distinction between past present and future But how could this be how could we be so wrong about something so familiar does it bother us? Absolutely, there's no principle built into the laws of nature that say that theoretical physicists have to be happy It's a game-changing perspective that opens up a new world of possibilities Coming on the realm of tiny atoms and particles the quantum realm The laws here seem impossible There's a sense in which things don't like to be tied down to just one location yet They're vital to everything in the universe. There's no disagreement between quantum Kanaks, and any experiment. That's ever been done What do they reveal about the nature of reality? Take a quantum leap on the fabric of the cosmos right now on, Nova Major funding for Nova is provided by the following David H Koch and Discovering new novels HH mi And by the Corporation for Public Broadcasting and by Contributions to your PBS station from viewers like you Thank you Major funding for the fabric of the cosmos is provided by the National Science Foundation where discoveries begin And The Alfred P sloan Foundation supporting original research and public understanding of science technology engineering and mathematics Additional funding is provided by the Arthur vining Davis foundations dedicated to strengthening America's future through education the US Department of Energy's Office of Science and the George D Smith Fund For thousands of years we've been trying to unlock the mysteries of how the universe works and We've done pretty well Coming up with a set of laws that describes the clear and certain motion of galaxies and stars and planets But now we know at a fundamental level things are a lot more fuzzy because we've discovered a Revolutionary new set of laws that have completely transformed our picture of the universe From outer space to the heart of New York City to the microscopic realm our view of the world has shifted Thanks to the strange and mysterious laws. That are redefining our understanding reality They're the laws of quantum mechanics Quantum mechanics rules over every atom and tiny particle in every piece of matter in Stars and planets in rocks and buildings and in you and me We don't notice the strangeness of quantum mechanics in everyday life, but it's always there if you know where to look You just have to change your perspective and get down to the tiniest of scales To the level of atoms and the particles inside them Down at the quantum level the laws that govern this tiny realm appear completely different from the familiar laws that govern big everyday objects and Once you catch a glimpse of them you never look at the world in quite the same way It's almost impossible to picture how weird things can get down to the smallest of scales But what if you could visit a place like this Where the quantum laws were obvious where people and objects behave like tiny atoms and particles? You'd be in for quite a show Here objects do things that seem crazy I Mean in the quantum world There's a sense in which things don't like to be tied down to just one location Or to follow just one path It's almost as if things were in more than one place at a time And What I do here can have an immediate effect somewhere else Even if there's no one there And here's one of the strangest things of all If people behave like the particles inside the atom then most of the time you wouldn't know exactly where they were Instead they could be almost anywhere until you look for them hey, I'm gonna have what he's having So why do we believe these bizarre laws well for over 75 years We've been using them to make predictions for how atoms and particles should behave and in experiment after Experiment the quantum laws have always been right It's the best theory we have there are literally billions of pieces of confirming evidence for quantum mechanics It has passed so many tests Or so many bizarre predictions. There's no disagreement between quantum Kanaks in any experiment. That's ever been done The quantum laws become most obvious when you get down to tiny scales like atoms but consider this I'm made of atoms so are you so is everything else we see in the world around us So it must be the case that these weird quantum laws are not just telling us about small things. They're telling us about reality So how did we discover them? The strange laws that seem to contradict much of what we thought we knew about the universe Not long ago. We thought we had it pretty much figured out The rules that govern how planets orbit the Sun? How a ball arcs through the sky How ripples move across the surface of a pond These laws were all spelled out in a series of equations call classical mechanics And they allowed us to predict the behavior of things with certainty It all seemed to be making perfect sense Until about a hundred years ago when scientists are struggling to explain some unusual properties of light In particular the kind of light that glowed from gases when they were heated in a glass tube When scientists observed this light through a prism they saw something. They'd never expected If you heated up some gas and looked at it through a prism it formed lines Not the continuous spectrum that you see you've projected by piece of cut glass on your table But very distinct lines It wouldn't give out a smear kind of complete rainbow of life it would give out a sort of pencil beams of light at very specific colors and It was something of a mystery how to understand. What was going on An explanation for mysterious lines of color would come from a band of radical scientists who at the beginning of the 20th century were grappling with the fundamental nature of the physical world and Some of the most startling insights came from the mind of Niels Bohr a physicist who loved to discuss new ideas over pingpong Bohr was convinced that the solution to the mystery lay at the heart of matter in the structure of the atom He thought that atoms resembled tiny solar systems with even tinier particles called electrons Orbiting around a nucleus Much the way the planets orbit around the Sun But or proposed that unlike the solar system electrons could not move in just any orbit Instead only certain orbits were allowed And he had a really surprising and completely counter physical idea which was that there were definite States fixed orbits that these electrons could have and Only those orbits Bohr said that when an atom was heated its electrons would become agitated and leaped from one fixed orbit to another Each downward leap would emit energy in the form of light in very specific wavelengths And that's why atoms produce very specific colors. This is where we get the phrase quantum leap If it weren't for the quantum leap you would have this Smear of color coming out from an atom as it got excited or D excited But that's not what we see in the laboratory you see very sharp red very sharp greens. It's the quantum leap That's the origin and the author of that sharp color What made the quantum leap so surprising is that the electron goes directly from here to there Seemingly without moving through the space in between It was as if Mars suddenly pop from its own orbit out to Jupiter Bohr argued that the quantum leap arises from a fundamental and Fundamentally weird property of electrons and atoms that their energy comes in discrete chunks that cannot be subdivided Specific minimum quantities called quanta and That's why there were only discrete specific orbits that electrons can occupy An electrons had to be here or there and simply nowhere in between and that's that's like nothing we experience in everyday life Think of your daily life When you eat food you think your food is quantized Do you think that you have to take a certain amount of minimum food food is not quantized? But the energy of electrons in an atom I confessed that Is very mysterious why that is As mysterious as it might be for tiny particles in an atom to act this way The evidence quickly mounted showing that or was right in more and more Experiments electrons followed a different set of rules than planets or ping-pong balls Borås discovery was a game changer And with this new picture of the atom Bohr and his colleagues found themselves on a collision course with the accepted laws of physics The quantum leap was just the beginning Soon Bohr's radical views would bring him head-to-head with one of the greatest physicists in history Albert Einstein was not afraid of new ideas but during the 1920s the world of quantum mechanics began to veer in a direction Einstein did not want to go a Direction that sharply diverged from the absolute definitive predictions that were the hallmark of classical physics If you asked I in Stein or other physicists at the time what it was that this distinguished physics from all kind of flaky speculation they would have said it's not that we can predict things with certainty and Quantum mechanics seemed to pull the rug out from under that One test in particular which would come to be known as the double slit experiment Exposed quantum mysteries like no other If you're looking for a description of reality based on certainty your expectations would be shattered We can get a pretty good feel for the double-slit experiments And how dramatically it alters our picture of reality by carry out a similar experiment not on the scale of tiny particles But on the scale of more ordinary objects like those you find here in a bowling alley But first I need to make a couple of adjustments to the lane You'd expect that if I roll a few of these balls down the lane well either be Stopped by the barrier or pass through one or the other slit, and hit the screen at the back And in fact, that's just what happens Those balls that make it through always hit the screen directly behind I'd to the left slit or the right slit The double slit experiment was much like this except instead of bowling balls You use electrons which are billions of times smaller You can picture them like this Let's see what happens if I throw a bunch of these balls When electrons are hurled at the two slits something very different happens on the other side Instead of hitting just two areas the electrons land all over the detector screen creating a pattern of stripes Including some right between the two slits the very place you think would be blocked So what's going on? Well two physicists even in the 1920s this pattern could mean only one thing Waves Waves do all kinds of interesting things Things that bowling balls would never do They can split they can combine If I sent a wave of water through the double slits it would split in two and then the two sets of waves would intersect their peaks and valleys would combine Getting bigger in some places Smaller in others and sometimes they cancel each other out With the height of the water corresponding to brightness on the screen The peaks and valleys would create a series of stripes and what's known as an interference pattern So how could electrons which are particles form that pattern How could a single electron end up in places a wave would go? particles of particles waves are waves How can a particle be a wave? Unless you give up the idea that it's a particle and think aha this thing that I thought was a particle was actually a wave Wave in an ocean. That's not a particle The ocean is made out of particles, but the waves in the ocean of my particles And rocks are not waves rocks are rocks So a rock is an example of a particle an ocean wave is an example of an ocean wave and now Somebody's telling you a rock is like an ocean wave What? Back in the 1920s when a version of this experiment was first done scientists struggled to understand this wavy behavior Some wondered of a single electron while in motion might spread out into a wave and The physicist Erwin Schrodinger came up with an equation that seemed to describe it Schrodinger thought that this wave was a description of an extended Electron that somehow an electron got smeared out, and it was no longer a point but was like a mush There was a lot of argument about exactly what this represented Finally a physicist named Max Born came up with a new and revolutionary idea for what the wave equation described Born said the wave is not a smeared out electron or anything else previously encountered in science Instead he declared. It's something that's really peculiar a probability wave That is born argue that the size of the way that any location predicts the likelihood of the electron being found there Where the wave is big that's not where most of the electron is that's where the electron is most likely to be and that's just Very strange right so the electron on its own seems to be a jumble of possibilities You're not allowed to ask, where is the electron right now? You are allowed to ask if I look for the electron in this little particular part of space What is the likelihood? I will find it there I? Mean that bugs anyone anytime As weird as it sounds this new way of describing how particles like electrons Move is actually right when I throw a single electron I can never predict where we'll land but if I use Schrodinger's equation to find the electrons probability wave I Can predict with great certainty that if I throw enough electrons then say? 33.1% would end up here 7.9% would end up there and so on these kinds of predictions have been confirmed again and again by experiments and So the equations of quantum mechanics turn out to be amazingly accurate and precise so Long as you can accept that it's all about probability If you think that probability means you're reduced in guessing the casinos of Las Vegas are ready to prove you wrong Try your hand at any one of these games of chance and you can see the power of probability Let's say I place a $20 bet on number 29 here at the roulette table The house doesn't know whether I win on this spin with an X or the next one But it does know the probability that we'll win in this game. It's 1 in 38 21 Twenty-nine So even though I may win now and then in the long run the house always takes him more than it loses The point is the house doesn't have to know the outcome of any single card game roll the dice or spin up the roulette wheel Casinos can still be confident that over the course of thousands of spins deals and rolls They will win and they can predict with exquisite accuracy Exactly how often? According to quantum mechanics the world itself is a game of chance much like this All the matter in the universe is made of atoms and subatomic Particles that are ruled by probability not certainty at base nature is described by an inherently probabilistic theory and That is highly counterintuitive and something which many people would find difficulty accepting one person who found it difficult was Einstein Einstein could not believe that the Fundamental nature of reality at the deepest level was determined by chance, and this is what Einstein could not accept Einstein said God does not throw dice He didn't like the idea that we couldn't be certain to say this happens or that happens But a lot of other physicists weren't so put off by probability because the equations of quantum mechanics gave them the power to predict the behavior of groups of atoms and tiny particles with astounding precision Before long that power would lead to some very big inventions Lasers transistors the integrated circuit the entire field of electronics if quantum mechanics suddenly went on strike Every single machine that we have in the u.s.. Almost would stop functioning the equations of quantum mechanics would help engineers design microscopic switches that direct the flow of tiny electrons and control virtually every one of today's computers digital cameras and telephones All the devices that we live on diodes transistors just to form the basis of information Technology the basis of daily life in all sorts of ways they work, and why do they work they work because of quanta Kanaks I'm tempted to say that without quantum mechanics. We'd be back in the dark ages. I Guess more accurately without quantum mechanics would be back in the 19th century Steam engines Telegraph signals Quantum mechanics is the most successful theory that we physicists have ever discovered And yet we're still arguing about what it means What it tells us about the nature of reality? In spite of all its triumph quantum mechanics remains deeply mysterious it makes all this stuff run But we still haven't answered basic questions raised by Albert Einstein all the way back in the 1920s and 30s questions involving probability and measurement the act of observation For niels bohr measurement changes everything He believed that before you measured or observed a particle its characteristics were uncertain For example an electron in the double slit experiment Before the detector at the fact pinpoints its location. It could be almost anywhere with a whole range of possibilities Until the moment you observe it and only at that point will the locations uncertainty disappear according to Bohr's approach to quantum mechanics When you measure a particle the act of measurement? forces the particle to relinquish all of the possible places it could have been and Select one definite location where you find it the act of measurement is what forces the particle to make that choice Niels Bohr accepted that the nature of reality was inherently fuzzy But not Einstein he believed in Certainty not just when something has measured or looked at but all the time As Einstein said I like to think the moon is there even when I'm not looking at it That's what I say Was was so upset about do we really think the reality of the universe rests on whether or not we happen to open our eyes That's just bizarre Einstein was convinced something was missing from quantum theory Something that would describe all the detailed features of particles like their locations even when you were not looking at them but at the time few physicists shared his concern and ISIF, just thought it was giving up on the job of the physicist it wasn't bad physics per se just was totally incomplete That's einstein's refrain quantum mechanics is not incorrect. It's as far as insofar as it goes, but it's incomplete It doesn't capture all the things that can be said were predicted with certainty Despite Einsteins arguments Niels Bohr remained unmoved when Einstein repeated that God does not play dice Bohr responded stopped telling God what to do? But in 1935 Einstein thought he'd finally found the Achilles heel of quantum mechanics Something so strange so countered all logical views of the universe He thought it. Held the key to proving the theory was incomplete It's called entanglement The most bizarre the most absurd the most crazy the most ridiculous prediction that quantum mechanics maze Is entanglement? Entanglement is a theoretical prediction that comes from the equations of quantum mechanics Two particles can become entangled if they're close together and their properties become linked Remarkably quantum mechanics says that even if you separated those particles sending them in opposite directions they could remain entangled inextricably connected To understand how profoundly weird this is consider a property of electrons called spin Unlike a spinning top an electron spin as with other quantum qualities is generally completely fuzzy and uncertain until The moment you measure it and when you do you'll find is either spinning clockwise Or counterclockwise It's kind of like this wheel when it stops turning. It will randomly land on either red or blue Now imagine a second wheel If these two wheels behave like two entangled electrons, then every time one landed red The other is guaranteed to land on blue and vice versa Now since the wheels are not connected That's suspicious enough, but the quantum mechanics embraced by Niels Bohr and his colleagues went even further Predicting that if one of the pair were far away even on the moon with no wires or Transmitters connecting them still if you look at one and find red the other is sure to be blue In other words if you measured a particle here Not only would you affect it, but your measurement would also affect its entangle partner no matter how distant? Reinstein that kind of weird long-range connection between spinning wheels or particles was so ludicrous He called it spooky spooky action at a distance What's surprising? Is that? When you make a measurement of one particle you affect the state of the other particle you change its state There's no forces or pulleys or you know telephone wires There's nothing connecting those things right how could my choice to act here have anything to do with what happens over there? So there's no way they could communicate with each other So it is completely bizarre Einstein just could not accept that entanglement worked this way Convincing himself that only the math was weird not reality He agreed that entangled particles could exist but he thought that there was a simpler explanation For why they were linked that did not involve mysterious long distance connection Instead he insisted that entangled particles were more like a pair of gloves Imagine someone separates the two gloves putting each in a case Then that person delivers one of those cases to me And since the other case grant article Thanks Before I look inside my case I know that it has either left hand or right hand glove and when I open my case If I find a left hand glove then at that instant I know that case in Antartica must contain a right hand glove Even though no one has looked inside There's nothing mysterious about this obviously by looking inside the case I've not affected either Glove this case has always had a left hand glove and the one in Antarctica has always had a right hand glove That was said when the moment the gloves were separated and packed away Now Einstein thought that exactly the same idea applies to entangled particles Whatever configuration the electrons are in must have been fully determined from the moment that they flew apart So who was right? Bohr who championed the equations that said that particles were like spinning wheels That could immediately link their random results even across great distances Or Einstein who believed there was no spooky connection, but instead everything was decided Well before you looked Well the big challenge in figuring out who is right Borenstein is that Einstein is saying a Particle say has a definite spin before you measure it How do you check that you say to Einstein? He says well measure it and you'll find the definite spin Or would say, but it's the act of measurement that brought that spin to a definite state No, one knew how to resolve the problem so the whole question came to be considered philosophy not science in 1955 Einstein died still convinced that quantum mechanics offered at best an incomplete picture of reality In 1967 at Columbia University Einstein's mission to challenged quantum mechanics was taken up by an unlikely recruit John clauser was on the verge of earning a PhD in astrophysics the Only thing standing in his way was his grade in quantum mechanics When I was still a graduate student try as I might I could not understand quantum mechanics Clauser was wondering if Einstein might be right when he made a life-altering discovery It was an obscure paper by a little-known Irish physicist named John Bell Amazingly Bell seemed to have found a way to break the deadlock between Einstein and Bohr and show once and for all who was right about the universe I Was convinced that the quantum mechanical view was probably wrong Reading the paper clauser saw that Bell had discovered how to tell if entangled particles were really communicating through spooky action like matching spinning wheels Or if there was nothing spooky at all and the particles were already set in their ways like a pair of gloves What's more with some clever mathematics Bell showed that if spooky action were not at work Then quantum mechanics wasn't merely incomplete as Einstein thought. It was wrong I Came to the conclusion that my god, this is one of the most profound results I've ever seen Bell was a theorist But his paper showed that the question could be decided if he could build a machine that created and compared many pairs of entangled particles Bell turned the question Into an experimental question it wasn't just gonna be about philosophy or trading pieces of paper and the experiment that he envisioned Could be done. You could really set up an actual experiment to force the issue Wowser said about constructing a machine that would finally settle the debate Now I was just this Punk graduate student at the time this really seems like wow There's always the slim chance that you will find a result that will shake the world Clauser x' machine could measure thousands of pairs of entangled particles and compare their spins in many different directions As a result started coming in clauser was surprised and not happy I Kept asking myself what have I done wrong? What mistakes have I made it is? Klaus who repeated his experiments and soon French physicist Elana spay developed a more sophisticated test With significantly more definitive results as babe removed virtually all lingering doubt Clauser x' and s phase results are truly shocking. They prove that the math of quantum mechanics is right Entanglement is real Quantum particles can be linked to the cross space Measuring one thing can in fact instantly affect its distant partners as if the space between them didn't even exist The one thing that Einstein thought was impossible spooky action at a distance actually happens I was again Because I still To this day still have great difficulty in understanding it That is the most bizarre thing of quantum mechanics It is impossible to even comprehend Don't even ask me. Why don't ask me what you're going to how it works because it's an illegal question All we can say is that is apparently the way the world picks So if we accept that the world really does tick in this bizarre way Could we ever harness the long distance spooky action of entanglement to do something useful? Well one dream has been to somehow transport people in things from one place to another without crossing the space in between in other words teleportation Star Trek has always made being or teleporting looked pretty convenient It seems like pure science fiction, but couldn't angleman make it possible Remarkably tests are already underway here on the Canary Islands off the coast of Africa We do the experiments here on the Canary Islands because you have two observatories and After all it's a nice environment Anton Zeilinger is a long way from teleporting himself or any other human But he is trying to use quantum entanglement to teleport tiny individual particles in this case photons particles of light He starts by generating a pair of entangled photons in a lab on the island of La Palma One entangle photon stays on the Palma while the other is sent by laser to the island of Tenerife 89 miles away Now Zeilinger brings in a third photon the one he wants to teleport and has it interact with the entangled photon on La Palma The team studies the interaction Comparing the quantum states of the two particles, and here's the amazing part because of spooky action the team is able to use that comparison to transform the entangle photon on the distant island into an identical copy of that third Photon It's as if the third photon has teleported across the sea without traversing the space between the islands Sort of extract the information carried by the original and make a new original there Using this technique is I linger has successfully teleported dozens of particles But could this go even further Since we are made of particles could this process make human teleportation possible one day Welcome to New York City Let's say I want to get to Paris for a quick lunch well in theory Entanglement might someday make that possible here's what I need The chamber of particles here in New York, that's entangled with another chamber of particles new Harris Right this way mr.. Green I would step into a pod that acts sort of like a scanner, or a fax machine While the device scans the huge number of particles in my body more particles and there are stars in the observable universe it's jointly scanning the particles in the other chamber and It creates a list that compares the quantum state of the two sets of particles and Here's where entanglement comes in because of spooky action at a distance that List also reveals how the original state of my particles is related to the state of the particles in Paris Next the operator sends that list to Paris there they use the data to reconstruct the exact quantum state of every single one of my particles and a new me materializes It's not that the particles traveled from New York to Paris it's that entanglement allows my quantum state to be extracted in New York and reconstituted in Paris down to the last particle Bonjour Monsieur Breen hi there so here I am in Paris an exact replica of myself And I better be because measuring the quantum state of all my particles in New York has destroyed The original me it is absolutely required in the quantum teleportation protocol that the thing that is teleported is destroyed in the process and You know that does make you a little anxious. I guess you would just end up being a lump of neutrons protons and electrons You wouldn't you wouldn't look too good? Now we are a long way from human teleportation today But the possibility raises a question is the Brian Green who arrives in Paris? Really me Well there should be no difference between the old me in New York and the new me here in Paris and the reason is that? According to quantum mechanics, it's not the physical Particles that make me me it's the information those particles contain and that information has been teleported exactly for all the trillions of trillions of particles that make up my body it is a very different question whether What arrives at the receiving station? Is the original or not? My position is that By original we mean something which has all the properties of the original and if this is the case then it is delusional I Wouldn't step into that machine Whether or not human teleportation ever becomes a reality The fuzzy uncertainty of quantum mechanics has all sorts of other potential applications Here at MIT Seth Lloyd is one of many researchers trying to harness quantum mechanics in powerful new ways Quantum mechanics is weird. That's just the way It is so you know life is dealing us weird lemons can we make some weird lemonade from this? Lloyd's weird lemonade comes in the form of a quantum computer These are the guts of a quantum computer This gold and brass contraption might not look anything like your familiar laptop, but at its heart it speaks the same language Binary code a computer language spelled out in zeros and ones called bits so the smallest chunk of information is a bit and What a computer does is simply busts up the information the smallest chunks, and then flips them really really really rapidly This quantum computer speaks in bits but unlike a conventional bit which at any moment can be either 0 or 1 a Quantum bit is much more flexible You know something here can be a bit here is 0 there is one That's a bit of information so if you can have something that's here and there at the same time then you have a quantum bit or qubit just as an electron can be a fuzzy mixture of spinning clockwise and counter clockwise a Quantum bit can be a fuzzy mixture of being a 0 and a 1 and So a qubit can multitask That it means you can do computations in ways that our classical brains could not have dreamed of In theory quantum bits could be made from anything that acts in a quantum way like an electron or an atom The qubits at the heart of this computer are tiny superconducting circuits built with Nanotechnology that can run in two directions at once Since quantum bits are so good at multitasking if we can figure out how to get qubits to work together to solve problems our computing power could explode exponentially To get a feel for why a quantum computer would be so powerful imagine being trapped in the middle of a hedge maze What you want is to find the way out as fast as possible the problem is there are so many options and I just have to try them out one at a time That means I'm going to hit lots of dead ends Go down lots of blind alleys And make lots of wrong turns Before I finally get lucky and find the exit and that's pretty much how today's computers solve problems Though they do it very quickly they only carry out one task at a time Just like I can only investigate one path at a time in the maze But if I could try all the possibilities at once it would be a different story and that's kind of how quantum computing works Since particles can in a sense be in many places at once The computer could investigate a huge number of paths or solutions at the same time and find the correct one in a snap Now a maze like this only has a limited number of routes to explore so a conventional computer could find the way out pretty quickly But imagine a problem with millions or billions of variables Like predicting the weather far in advance We might be able to forecast natural disasters like earthquakes or tornadoes solving that kind of problem right now would be impossible because it would take a ridiculously huge computer But a quantum computer could get the job done with just a few hundred atoms and so the brain of that computer It would be smaller than a grain of sand There's no doubt we're getting better and better at harnessing the power of the quantum world and who knows where that could take us But we can't forget that at the heart of this theory which has given us so much There is still a gaping hole All the weirdness down at the quantum level at the scale of atoms and particles Where does the weirdness go? Y-q things in the quantum world hover in a state of uncertainty Seemingly being partly here and partly there with so many possibilities while you and I who? After all are made of atoms and particles Seem to always be stuck in a single definite state. We are always either here or there niels bohr offered no real explanation for why all the weird fuzziness of the quantum world seems to vanish as things increase in size As powerful and accurate as quantum mechanics has proven to be Scientists are still struggling to figure this out Some believe that there's some detail missing in the equations of quantum mechanics And so even though there are multiple possibilities in the tiny world The missing details would adjust the numbers and our way up from atoms to objects in a big world So that it would become clear that all but one of those possibilities disappear resulting in a single certain outcome Other physicists believe that all the possibilities that exist in the quantum world they never do go away Is that each and every possible outcome actually happened? only most of them happen in other Universes parallel to our own It's a mind-blowing idea But reality could go beyond the one universe we all see and be constantly branching off creating new Alternative worlds where every possibility gets played out This is the frontier of quantum mechanics and no one knows where it will lead The very fact that our reality is much grander than we thought much more Strange mysterious than we thought is to be also very beautiful and awe-inspiring The beauty of science is that it allows you to learn things which go beyond your wildest dreams And quantum mechanics is the epitome of that after you learn quantum mechanics? Your your never really the same again As Strange as quantum mechanics may be what's now clear is that there's no boundary between the worlds of the tiny and the big Instead these laws apply everywhere, and it's just that the weird features are most apparent when things are small and So the discovery of quantum mechanics has revealed a reality our reality That's both shocking and thrilling bringing us that much closer to fully understanding the fabric of the cosmos Major funding for Nova is provided by David H coke and Discovering new knowledge H h mi And by the Corporation for Public Broadcasting and by Contributions to your PBS station from viewers like you. Thank you Major funding for the fabric of the cosmos is provided by the National Science Foundation where discoveries begin And The Alfred P sloan Foundation supporting original research and public understanding of science technology engineering and mathematics Additional funding is provided by the Arthur vining Davis foundations dedicated to strengthening America's future through education the US Department of Energy's Office of Science and The George D Smith Fund You