Mind-Blowing Facts About Our Reality [4K] | The Secrets of Quantum Physics | Spark

there's a way to make an entrance my destiny it was now a conspiracy of witches download vili today [Music] beneath the complexities of everyday life the rules of our universe seem reassuringly simple this solid Bridge supports my weight the water flowing underneath always goes downhill and when I throw this Stone it always flies through the air following a predictable path but as scientists peered deep into the tiny building blocks of matter all such certainty vanished they found the weird world of quantum mechanics deep down inside everything we see around us we found a universe completely unlike our own to paraphrase one of the founders of quantum mechanics everything we call real is made up of things that cannot be themselves regarded as real foreign years ago some of the world's greatest scientists began a journey down the rabbit hole into the strange and the bizarre they found that in the realm of the very small things could be in two places at once that their Fates are dictated by chance [Music] and that reality itself defies all common sense and at stake that everything we thought we knew about the world might turn out to be completely wrong the story of our descent into scientific Madness begins with the most unlikely object Berlin 1890. Germany is a new country recently unified and hungry to industrialize in this newly unified Germany a number of new engineering companies were founded they had spent Millions buying the European patent for Edison's new invention the light bulb the light bulb was the epitome of modern technology a great optimistic symbol of progress engineering companies quickly realized there were fortunes to be made building street lights for the new German Empire but what they didn't realize was that they would also unleash a scientific revolution strangely enough this humble object is responsible for the birth of the most important theory in the whole of science quantum mechanics a theory that I've spent my life studying and that's because back in 1900 the light bulb presented a rather strange problem Engineers knew that if you heated the filament with electricity it glowed the physics that underpinned this though was completely unknown that something as basic as the relationship between the temperature of the filament and the color of light it produces was still a complete mystery a mystery they were obviously Keen to solve and with the help of the new German State they saw how to steal a march on their competitors in 1887 the German government invested millions in a new technical Research Institute here in Berlin the physicalist technician Russian starts or PTR then in 1900 they enlisted a bright if somewhat straight-less scientist to help work here his name was Max Planck Planck took on a deceptively simple problem why the color of the light changes as the filament gets hotter forget a sense of the puzzle facing plank I'm going to ride this bicycle with an old-fashioned lamp powered by an old-fashioned Dynamo [Music] um obviously the faster I go the brighter the light the more I pedal the more electricity the Dynamo produces the hotter the filament in the lamp and the brighter the light but the light the Bold makes isn't just getting brighter it's changing color too as I speed up the color shifts from red to orange to Yellow right now I'm going to really belt it [Music] now the bulbs filament is but although it certainly gets brighter the color seems to stay the same yellow white foreign why doesn't the light get any Bluer to investigate Plank and his colleagues built this a black body radiator it's a special tube they could heat to a very precise temperature and a way to measure the color or frequency of the light It produced [Music] nowadays over a hundred years later the PTR still do exactly this kind of measurement just much more accurately the temperature inside here is 841 degrees Centigrade feel the heat coming off and it's glowing with a lovely orangey red color it's about the same color as my bike light when I'm cycling slowly I want to see something hotter still the temperature inside here is about 2 000 degrees Centigrade and it's glowing with a much brighter whiter colored light produce light of this intensity and color requires a power of about 40 kilowatts now that's equivalent to about 400 meters on a bike cycling very fast or the combined output of the entire Tour de France although the light is whiter it's red white there's very little blue why is blue so much harder to make than red and further up the Spectrum Beyond blue the so-called ultraviolet is hardly produced at all even when we look at things as hot as the sun even the Sun at a temperature of five and a half thousand degrees Centigrade produces mostly white visible light and makes remarkably little ultraviolet light given how hot it is why is this why is ultraviolet light so hard to make remarkable failure of common sense so perplexed scientists of the late 19th century that they gave it a very dramatic name they called it the ultraviolet catastrophe plank took a crucial first step to solving this he found the precise mathematical link between the color of light its frequency and its energy but he didn't understand the connection however it was another weird anomaly that would really put the cat amongst the pigeons in the late 19th century scientists were studying that their newly discovered radio waves and how they were transmitted and to do that they were building experimental rigs very similar to this one basically by spinning this disc that could generate huge voltages that caused Sparks to jump across the gap between the two metal spheres but in doing so they discovered something very unexpected to do with light they found that by shining a powerful light source on the Spheres they could make the Sparks jump across more easily this suggested a mysterious and unexplained connection between light and electricity [Music] to understand what was happening scientists use this it's called a gold leaf electroscope it's basically a more sensitive version of the spark gap apparatus now first of all I have to charge it up what I'm doing is adding an excess of electrons that are pushing the two gold leaves apart first I take red light and shine it on the metal surface and nothing happens even if I increase the brightness of the light still the gold leaves aren't affected now I'll try this special blue light rich in ultraviolet immediately the gold leaves collapse [Music] light can clearly remove static electric charge from the leaves it can somehow knock out the electrons I added to them but why is ultraviolet light so much better at doing this than red light this new puzzle became known as the photoelectric effect the ultraviolet catastrophe and the photoelectric effect were big problems for physicists because neither could be understood using the best science of the time science that said quite unequivocally that light was a wave [Music] all around us we see light behaving in a perfectly Common Sense wavy way look at the shadow of my hand it's fuzzy around the edges we understand this as the light hitting the sides of my hand and bending and smearing out slightly just like water waves around an obstruction perfectly Common Sense wave-like Behavior and here's something else something rather beautiful look at these soap bubbles shine a light on them and gorgeous colored patterns emerge from nowhere and this was easily explained if you accept that light was a wave reflecting off the outer and inner layers of the thin soap film and breaking up into the colors of the rainbow rather like ripples on the surface of water light was simply ripples of energy spreading through space and this was as firmly accepted as the fact that the Earth was round but although this wave theory worked perfectly well for shadows and Bubbles when it came to the ultraviolet catastrophe and the photoelectric effect the wheels started coming off the problem was this how could light do this to truly grasp how absurd this phenomenon was it might be useful to consider how waves in water behave all right [Music] this is the wave tank at the rnlise headquarters in Dorset it's used to train Lifeboat teams to deal with a range of different kinds of water waves first small waves just 30 centimeters high these waves don't have much energy hardly enough energy to knock this top hand off the other but when the waves grow to over a meter and a half is a very different proposition [Music] [Music] it's clear what water waves are telling us bigger more intense waves have more power they easily knocked me and the cans around so if light was a wave more intensity should knock out more electrons that's not what happened remember no matter how intense the red light was it still didn't budge electrons from the metal but weirdly weak ultraviolet worked within seconds so thinking of light as a wave just wasn't adding up okay to resolve this someone needed to think the unthinkable and in 1905 someone did you may well have heard of him his name was Albert Einstein [Music] this is the aachenhold sternvark observatory in Berlin perched on top is a strange huge Iron and Steel construction but it's not a gun it's actually a telescope foreign built in 1896 the telescope was one of the largest of its kind in the world and made the observatory the go-to place to engage and Astound the public in new science Albert Einstein gave a very famous public lecture here on his theory of relativity which is of course what he's most famous for but it's not the work that won him the Nobel Prize [Music] in 1905 he'd also come up with a new Theory to explain the photoelectric effect what he suggested was revolutionary and even heretical [Music] he argued that we have to forget all about the idea that light is a wave and think of it instead as a stream of tiny bullet-like particles the term he used to describe a particle of light was a Quantum to Einstein a Quantum was a tiny lump of energy and although in 1905 the word wasn't new the idea that light could be a Quantum seemed crazy foreign following Einstein's heretical line of thought to its logical conclusion solved all the problems with light at a single stroke I'll try to explain how this helps using a rough analogy of course like all analogies it's far from perfect but hopefully it'll give you a sense of the physics to help you understand why thinking of light as a stream of particles solves the mystery of the photoelectric effect in this analogy these red balls represent Einstein's light quanta and those cans over there are the electricity held in the metal now in the original experiment they made electricity flow from the surface of the metal by Shining Light on it in my analogy I'm going to try and knock those tin cans over using these red balls [Music] absolutely no effect [Music] that's just like red light [Music] according to Einstein each particle of red light carries very little energy because red light has a low frequency so even a very bright red light with many red light particles can't dislodge any electrons from the metal plate just like the red balls now I'm going to use heavier balls like these blue golf balls and I'm going to try and knock off the tin cans with these foreign lights in the experiment [Music] now each individual light particle carries more energy because ultraviolet light is higher frequency [Music] just a few of them like a dim ultraviolet light are enough to knock the electrons out of the metal plate and collapse the gold leaf so Einstein's idea that light is made up of tiny particles or quanta is a wonderful explanation of the photoelectric effect I remember when I first learned about this being blown away by Sheer Elegance and simplicity but what's more Einstein's Nifty idea all to help solve Planck's mystery of the light bulb there was more red than ultraviolet because ultraviolet quanta took so much more energy to make about a hundred times more energy no wonder there are so few of them that moment at the beginning of the 20th century signaled a genuine Revolution because it demonstrated that the kind of physical science of people were doing right back to Newton and LaPlace and people like that that you needed a completely new approach physics has never recovered from that moment in the sense that it's built on that moment that's where Modern physics really began but Einstein's theory also left physicists with a dizzying paradox defying all common sense light was definitely a wave which explained shadows and Bubbles and now it was definitely a particle too Einstein's quanta explaining the photoelectric effect and the ultraviolet catastrophe then just a few years after Einstein's brilliant crazy idea the Paradox got a lot deeper and a whole lot weirder because what seemed to be a curious mystery about light was about to become a Battleground but the nature of reality itself 1922 the Western world is in the grip of a revolution a cultural revolution James Joyce's Ulysses is published Stravinsky is at the height of his powers and Chaplin has just released his first serious movie the Ottoman Empire collapses Europe is still recovering from the war to end or Wars in which millions of men lost their lives Russia is newly communist meanwhile America is exporting Jazz to the world thank you [Music] in arts politics literature economics there was an insatiable appetite for change this was the birth of modernism you got a heart that there's no way of knowing you can see where you are but can't see where you're going and I'm stuck here still I'm tangled up with you [Music] this whole world can be so unsaid but and I might get into trouble for saying this I would argue that the upheaval that took place in physics at this time would Eclipse them all and have far longer lasting consequences it had begun with the discovery of the weird and contradictory wave particle nature of light they ended up as an epic battle fought between the greatest minds and science for the highest possible Stakes the nature of reality itself [Music] on one side a new wave of modernist revolutionary scientists and their leader the brilliant Danish physicist Niels Bohr on the other side the voice of reason Albert Einstein at the height of his powers are now world famous a formidable adversary [Music] the battle raged for decades actually in some ways it still does it was fought across the world in Universities at conferences in bars and cafes it would reduce grown men to tears and it began with a deceptively simple experiment [Music] but weirdly it was an experiment that wasn't even about light was about the particles that make electricity in the mid-1920s an experiment was carried out at Bell Laboratories in New Jersey In America which uncovered something entirely unexpected about electrons now at the time it was accepted without question that electrons were these tiny lumps of matter small but solid particles like miniature billiard balls in the experiment they fired a beam of electrons at a crystal and watched how they scattered now that's entirely equivalent to taking a beam of electrons say from an electron gun and firing it at a screen with two slits in it so that the electrons pass through the slits and hit another screen at the back what the Bell science has found shocked the physics world to the Core to understand why consider a similar experiment with water waves I've set up a simple experiment I have a water ripple tank placed on top of an overhead projector I have a generator producing waves that pass through two narrow gaps the projector beams the image of the Waves onto the back wall you can see as the waves come in from the left and squeeze through the two gaps they spread out on the other side and interfere with each other what this means is that when you get the crest from one wave meeting the crest from another they add up to make a higher wave but when the crest from one meets a trough they cancel out this gives rise to these characteristic lines leading to the signature wave pattern bands of light and dark whenever you see these light and dark bands the signature wave pattern you know without doubt that you've got wave-like Behavior [Music] so guess what they saw in New Jersey now it seemed that firing electrons tiny solid particles through the two gaps produced exactly the same kind of pattern bands of light and dark first light for a long time believed to be a wave was found to sometimes behave like particles and now electrons for a long time believed to be particles were behaving like waves but it was actually Stranger Than That the wave pattern wasn't merely some result of the entire beam of electrons more recently this experiment has been repeated in labs around the world by firing one electron at a time through the slits onto the screen at first each electron seems to land randomly on the screen a signature wave pattern let me be quite clear about just how weird this is remember from the wave tank experiment where the signature wave pattern only exists because each wave passes through both slits and then it's two pieces interfere with each other but here every individual electron each single particle is passing alone through the slits before it hits the screen and yet each single electron is still contributing to the signature wave pattern each electron can be behaving like a wave to explain this strange result Niels Bohr and his colleagues created quantum mechanics the crazy theory of light and matter that embraced contradiction and didn't care that it was almost impossible to understand as Niels Bohr himself said anyone who isn't shocked by quantum theory hasn't understood it so viewers I'm going to take our tiny electron and use it to delve deep into the heart of reality and yes prepare to be shocked because this is the only way to explain what we observe when a single electron travels through the slits and hits the screen quantum mechanics says this we can't describe what's traveling as a physical object all we can talk about are the chances of where the electron might be this wave of chance somehow travels through both slits producing interference just like the water wave then when it hits the screen what was just the ghostly possibility of an electron mysteriously becomes real let me try and capture just how weird this is with an analogy if I spin this coin then all the time is spinning it's a blur I can't tell if it's heads or tails but if I stop it I force it to decide and its heads so before it was sort of not heads or tails but a mixture of both but as soon as I've stopped it I've forced it to make up its mind this is what boar and his supporters claimed was happening with our electrons [Music] in a sense as it spins the coin is both heads and tails similarly the electrons wave of chance passes through both slits two paths at the same time our coin then stops at heads the Ethereal wave of probability hits the screen and only then becomes a particle the quantum world was unlike anything ever seen before it's hard to overstate just how crazy this is ball was effectively claiming that one can never know where the electron actually is at all until you measure it and it's not just that you don't know where the electron is it's weirdly as though the electron itself is everywhere at once bear in mind that electrons are among the commonest and most basic building blocks of reality and yet here's Bohr saying that only by looking do we actually conjure their position into existence it's like there's a curtain between us and the quantum world and behind it there is no solid reality just the potential for reality things only become real when we pull back the curtain and look and this you ladies and gentlemen became known as The Copenhagen interpretation [Applause] persuasive as it might seem many people couldn't stomach Niels balls outlandish ideas and they found a natural leader in the most powerful man in science Albert Einstein hated this interpretation with every fiber of his being he famously said does the moon cease to exist when I don't look at it he was very unhappy because it gave limits to knowledge that he didn't think should be final he thought there should be a better underlying Theory over the next 10 years Einstein and ball would argue passionately about whether quantum mechanics meant giving up on reality or not then with two other scientists Nathan Rosen and Boris Podolski Einstein thought they'd found a way to win the argument he was convinced he'd found a fatal flaw in the Copenhagen interpretation and its claim that reality was summoned into existence by the act of looking at it at the heart of Einstein's argument was an aspect of quantum mechanics called entanglement now entanglement is this special incredibly close relationship between a pair of quantum particles whose Fates are intertwined for example if they were created in the same event they try and explain this by imagining the two particles are Spinning Coins imagine are two electrons created from the same event and then moved apart from each other quantum mechanics says that because they're created together they're entangled and now many of their properties are forever linked wherever they are remember the Copenhagen interpretation says that until you measure one of the coins neither of them is heads or tails in fact heads and tails don't even exist and here's where entanglement makes this weird situation even weirder when we stop the first coin and it becomes heads because the coins are linked through entanglement the second coin will simultaneously become tails and here's the crucial thing I can't predict what the outcome of my measurement will be only that they will always be opposite Einstein seized on this [Applause] because it meant that something was happening between the two coins the almost too crazy to imagine [Music] it's as if the two coins are secretly communicating communicating instantaneously across space and time even if the First Column was on earth and the other was on Pluto Einstein refused to believe this instantaneous faster than light communication his theory of relativity said that nothing could travel that fast not even information so how could one coin instantaneously know how the other would land he disparagingly called it spooky action at a distance and claimed it was a fatal flaw in the Copenhagen interpretation what's more he had a better idea Einstein believed there was a simpler interpretation that somehow the destiny of the two coins whether or not they ended up heads or tails was already fixed long before we observed them [Applause] he said that although it seemed the coin was deciding to be say heads at the moment of observation actually that decision was taken long before it was just hidden from us in Einstein's mind Quantum particles were nothing like Spinning Coins they were more like say a pair of gloves left and right separated into boxes we don't know which box contains which glove until we open one but when we do and find say a right-handed glove then immediately we know that the other box contains the left-handed glove but crucially this requires no spooky action at a distance neither glove has been altered by the act of observation both of them were either left or right-handed glove from the beginning and the only thing that has changed is our knowledge so which is the true description of reality Boar's coins which only become real when we look at them [Music] and then magically communicate to each other or Einstein's gloves which are hidden from us but are definitely left or right from the beginning in other words is there an objective reality as Einstein believed or not as boar maintained in the late 1930s as the world plunged into war there was no way to answer this question the battle to understand the nature of reality was deadlocked the war rolled across Europe and many of the leading scientists fled to the United States then as the second world war led inexorably to the Cold War American Science backed by dollar bills and a new vision of the future boomed remember after the war visitors came back raring to go and try to apply the ideas of quantum theory to uh to atoms the interaction between electrons and light and what have you you didn't need to worry about the philosophical side of things to make progress with that so as you say it really took a back seat [Music] quantum mechanics led to a profound understanding of semiconductors which helped create the modern electronic age It produced lasers revolutionizing Communications breathtaking new medical advances breakthroughs in nuclear power quantum mechanics was so successful that most working physicists deliberately chose to ignore Einstein's objections it simply didn't matter to them because it worked they even coined a phrase for it shut up and calculate and the price for this success was that Boren Einstein's debate on the reality of the quantum world was simply brushed under the carpet [Music] and amidst all this success and pragmatism there were few who still worried what it all meant but as the 50s rolled headlong into the 60s one lone dissenter worked out how to settle the argument once and for all John Bell I think is fair to say isn't well known to the General Public but to physicists like me he's well a hero he was an original thinker with real courage in his convictions and the story of his rise to become one of the greats of physics is made even more remarkable when you consider how he started he was born in Belfast in the 1920s into a poor working-class family his father was a horse dealer and they really struggled to get him into Queen's University Belfast to study Physics in fact he was the only one in his family to even finish school this I believe made him insatiably curious fiery and stubborn I remember meeting John Bell in 1989 a year before he died we were both at a conference in America and we happened to be sharing a lift just after both attending a talk on quantum mechanics Keen to say something to the great John Bell I said I thought the the speaker's conclusions were completely crazy he he stared at me with his piercing blue eyes and for a moment I thought my fledgling physics career was going down the drain but as the lift doors opened and he was about to leave he said yes I completely agree with you haven't they heard of the helium problem to this day I'm not quite sure what the helium problem is but I was just so relieved that John Bell and I agreed for many years he worked here at Britain's Atomic Energy Research Center at Harwell who built this early experimental nuclear reactor called Dido it was here that he started pondering the deep and worrying questions that quantum mechanics raised did the quantum world only exist when it was observed or was there a deeper truth out there waiting to be discovered in fact he was so troubled he began to wonder if there was a problem at the heart of quantum mechanics he famously said I hesitate to think it might be wrong but I know it is rotten and so in the early 1960s Bell decided to try and resolve the crisis at the heart of quantum physics it was an epic challenge after all how do you check if something is real if something is or isn't there all without looking how do you look behind the curtain without pulling it open John Bell came up with a brilliant way of doing exactly that [Music] I think this is one of the most ingenious ideas in the whole of physics is certainly one of the most difficult to understand and explain but I'm going to try and have a go and yes I'm afraid I'm going to use another analogy this time I'm going to play a game of cards but it's one for the highest possible Stakes the nature of reality itself the card game is against a mysterious Quantum dealer the cards he deals represent any subatomic particles or even quanta of light photons and the game we'll play will ultimately tell us whether Einstein or ball was right now the rules of the game are deceptively simple the dealer is going to deal two cards face down if they're the same color I win if they're different colors I lose so I have a red so I need another red to win that's black I lose again opposite colors I've lost both those that's four in a row [Music] that's six pairs in a row that I've lost okay I think I know what the deal is doing here clearly the deck has been rigged in advance so that every pair come out as opposite colors but there's a simple way to catch the dealer out so what we can do now is change the rules of the game this time if they are the opposite color I win [Music] but once again every time my evil Quantum opponent beats me but again I can see what the karate dealer could have done maybe while I wasn't looking he's switched the pack and and rigged it so that it always lands in his favor now if repair is the same color rigged decks remember were what Einstein thought was really happening in the entanglement experiment he said that just like the gloves were already placed in the box so the evil dealer stacked the cards before we played but Neil's Boar's idea was very different he said red and black don't even exist until you turn them over Belle's genius was that he came up with a way of deciding once and for all who was right Einstein or boar this is how he did it I'm now not going to tell the dealer which game I want to play same color wins or different color wins until after he's dealt the cards [Music] now because he can never predict which rules I'm going to play by he can never stack the deck correctly now he can't win can he so now the rules are different wins the same okay same color wins this gets to the very heart of Belle's idea if we now start playing and I win as many as I lose then Einstein was right the dealer is just a trickster with a gift for sleight of hand reality may be tricky but it does have an objective existence what if I lose well then I'm forced to admit that there is no sensible explanation card must be sending secret signals to the other across space and time in defiance of everything we know I'm forced to accept that at the fundamental Quantum level reality is truly unknowable [Music] Bell reduced this idea into a single mathematical equation that tells us once and for all what seemed unanswerable how reality really is John Bell published his idea in 1964 and the extraordinary thing is at the time the entire physics Community ignored him total radio silence it seems the world simply wasn't ready perhaps it was because his equation seemed untestable or just because nobody thought it was worth investigating but that was about to change and the change would come from a very unexpected place [Music] [Music] America was in crisis over Vietnam Watergate feminism the Black Panthers and while all this was going on a small group of hippie physicists were working at the University of Berkeley in California they did all the hippie things they smoked dope they popped LSD they debated things like Buddhism and telepathy [Music] and they loved quantum mechanics in its weird version of reality they saw parallels with their own esoteric beliefs foreign [Music] style physics also caught the attention of the public who read their crazy hippie books that mixed quantum mechanics with Eastern mysticism books like the Tower of physics the dancing woolly Masters and my personal favorite space-time and Beyond towards an explanation of the unexplainable but more importantly for our story the story of quantum mechanics these hippie physicists also turn their attention to Einstein's now famous thought experiment and what it told us about the nature of reality they saw Niels Bohr's secret signaling as proof that physics supported their own ideas because if two particles could spookily communicate across space then ESP telepathy and Clairvoyance were probably true as well only they could prove it really existed then in 1972 they realized that with a bit of mathematical sleight of hand they could take Bell's equation and experimentally test it one of their group John clauser borrowed some equipment from the lab he was working in and set up the first genuine and ultimate test of quantum mechanics this is a picture of that first experiment built of leftovers and stolen equipment over the next few years it was improved by a team led by Alan aspect in Paris making its results more reliable over 10 years after Bell first proposed his equation finally it could be put to the test this is a modern version of the experiment first carried out by John clauser and then Alan aspect here a crystal converts laser lights into pairs of entangled light quanta photons making two very precise beams these photons are passed round and bent back again until they pass through these detectors the two photons are like the two cards the evil dealer places in front of me we'll measure a property of the photons called polarization which is equivalent to the color of the playing cards in my game so for instance winning with two matching red cards might be the same as two photons with matching polarization but because this is quantum mechanics it's more complicated than my simple card game and these dials here allow me to measure a second property of the photons as well now that's equivalent to me not only trying to guess the color of the face of the cards but also trying to guess the color of the back of the cards okay so we're now going to switch on the laser and start the experiment so this number here gives me the number of photon pairs coming through the experiment that's equivalent to the pairs of cards in my game the graph here dropping down gives me the probability that I can win that I'm guessing right the more photons the more accurate it becomes I'll stop at an uncertainty of about one percent and the final answer is 0.56 so if I put that into my equation I now need to run The Experiment three more times corresponding to the four different settings of these dials each run is now like a different set of rules for the quantum dealer and when I add them up and get the answer if it's less than two then Einstein was right if it's greater than 2 then ball was right okay so now for the second setting just remember what the experiment will show if the numbers come out less than two then it's proof the dealer has been stacking the deck this was Einstein's view okay so the number I get this time is 0.82 now reset for run three but if the result is greater than two then the deck cannot be stacked and something else is at work okay so the Run 3 result is minus 0.59 and finally run 4. this last number will finally reveal if the world follows common sense something much more bizarre okay so our final result is in and it's 0.56 so if we turn the laser off right I better just work out the answer and there we have it 2.53 it's a number greater than two absolute proof that Albert Einstein was wrong and Neil's ball was right the significance of this result is simply enormous just remember what it means Einstein's version of reality cannot be true no amount of clever jiggery pokery with our experiment can cheat nature the two entangled photons properties couldn't have been set from the beginning but are summoned into existence only when we measure them something strange is linking them across space something we can't explain or even imagine other than by using mathematics and weirder futons do only become real when we observe them in some strange sense it really does suggest the moon doesn't exist when we're not looking it truly defies common sense no wonder towards the end of his life Einstein wrote all these 50 years of conscious brooding have brought me no nearer to the question what are like quanta every Tom Dick and Harry thinks he knows it that he is mistaken the experiment only confirms this whatever is happening we just don't understand it but it doesn't mean we should stop looking while it's true that Einstein's dream of finding a reasonable Common Sense explanation was shattered for good my own personal view is that this doesn't necessarily banish physical reality like Einstein I still believe there might be a more palatable explanation underlying the weird results of quantum mechanics but one thing is clear whether there are physical spooky connections whether there are parallel universes whether we bring reality into existence by looking whatever the truth is the weirdness of the quantum World won't go away it'll rear its ugly head somewhere 120 years ago the greatest Scientific Revolution ever was brought about by a light bulb and scientists are still using powerful light sources like x-rays to unlock Nature's Mysteries this is the diamond light source it's Britain's single larger science facility the x-rays produced here are 10 billion times more powerful than a Hospital X-ray with that sort of power scientists can slice into matter and Glimpse those Quantum Secrets inside researchers here are using this powerful light beam to investigate new materials which may have the potential to bring about an Electronics breakthrough as great as any before just as the quantum pioneers of the 20s and 30s ended up bringing about a scientific and technological Revolution so this generation of physicists are set to usher in a new Quantum era [Music] an era where Einstein's hated quantum entanglement now produces unbreakable computer security new kinds of communication systems super fast computers and other advances we can't yet even imagine and this is why quantum mechanics Thrills and frustrates me it's capricious it's counter-intuitive it even sometimes feels just plain wrong and yet it still surprises us every day and I for one believe that our knowledge of the quantum World Is Still far from complete that there are greater truths about nature yet to be discovered and that's still what keeps me awake at night this week join me as my journey into the quantum world gets even more I investigate how its weird rules are crucial for life and how the bizarre behavior of subatomic particles might even influence Evolution itself welcome to a new and very strange World of Nature taken over by the weird subatomic particles of quantum physics as a physicist I've spent my working life studying how these particles behave in the laboratory but now I'm heading out into the natural world I'm on a mission to prove that quantum physics can solve the greatest mysteries in biology this is a real adventure for me I'm very much out of my comfort zone trying to apply the very careful ideas I'm familiar with in a Physics laboratory to the messy world of living things [Music] I believe that quantum physics could hold many of life's secrets that deep in the cells of animals particles glide through walls like ghosts [Music] that when plants capture sunlight their cells are invaded by shimmering waves that can be everywhere at the same time [Music] and that even our human senses are tuning into strange Quantum vibrations [Music] in the Fantastic world of quantum biology life is a game of chance played by Quantum rules this is what I hope to convince you of to show you that quantum mechanics is essential in explaining many of the important processes in life and potentially that quantum mechanics may even underpin the very existence of life itself foreign begins with one of the most majestic sights in nature migration every winter Barnacle geese arrive right on cue at the same Scottish River the end of an epic 2000 mile Voyage from svalbard high above the Arctic Circle of course many birds head south for winter then back home for summer but for decades exactly how birds navigated with such a CK was one of the greatest mysteries in biology [Music] so the most recent discovery has caused a sensation yeah in the past few years one species of bird has helped create a scientific revolution I was one of many physicists who were shocked to discover that it navigates using one of the strangest tricks in the whole of science it utilizes a quirk of quantum mechanics one Bamboozled even the greatest of physicists from Richard Feynman to Albert Einstein himself so you might be surprised to discover the identity of this mysterious creature say hello to the quantum Robin [Music] this is the European Robin every year she migrates from northern Europe to the tip of Spain and back in this laboratory in the woods biologist Henrik Morrison is trying to solve the mystery of how she does it but he's found himself in my world The Strange World of quantum mechanics quantum mechanics describes the very weird behavior of subatomic particles down in this realm of the very small we have to abandon common sense and intuition Instead This is a world where objects can spread out like waves Quantum particles can be in many places at once and send each other mysterious Communications I set out to understand how the bird Finds Its way but it just turned out that the data more and more pointed towards this as the only explanation that could bring all the different results together it's investigating a long-standing theory that Robins navigate by the Earth's magnetic field his laboratory is an ingenious magnetic bird cage and these plastic cones lined with scratch sensitive paper provide the key measurements [Music] Hendrick's artificial magnetic field is like the earth except that he can point it in any direction he likes [Music] inside their cones the robins always respond to the field leaving scratches in a single Direction the big mystery is how the Earth's magnetic field is incredibly weak far too weak for any living creature to detect but Henrik has found an intriguing clue by giving the quantum Robin a mask we have a little leather Hood similar to what you put on a falcon you know but just for Robin and you have then a hole in front of one eye or a hole in front of the other eye but what we can see is that if you cover up the right eye you turn off their magnetic compass processing in the left part of the brain If you cover up this eye you turn the compass off in this part of the brain The Robin's magnetic compass seemed to be in her eyes I can show you what's going on using my own eye now we use our eyes for vision but we also have a second light detecting mechanism if I shine this torch into my eye you can see that my pupil closes down it's basically a defense mechanism to protect my eyes my eye is responding to particles of light or photons the energy provided by the photons is clearly enough to activate chemical reactions after all that's what controls my eye muscles light must be causing similar chemical reactions in the Robin's eyes in fact it's the power supply for a unique form of magnetic compass inside her cells in the weird world of subatomic particles a place where only quantum physics can explain what's going on to see why imagine the chemical reactions in the Robin's eye taking place in mountains and valleys of energy to get a reaction to start you have to push molecules to the top of a mountain thanks to henrik's experiments we now know that light does most of the hard work when it reaches the free Peak the molecule becomes incredibly sensitive to the slightest touch the key Point here is that the Robin's chemical Compass is now balanced on an energy Peak between two valleys going one way produces one set of chemical products the other a different set now even a tiny change in the earth magnetic field can the molecule over the top but the way this happens defies Common Sense the final piece of the puzzle depends on one of the truly mind-boggling ideas in physics but don't worry if you find it hard to understand even Albert Einstein called it spooky the idea is called quantum entanglement it involves particles that seem to communicate faster than the speed of light in 1935 Einstein published a famous paper arguing that it was impossible but Einstein was wrong in recent years extremely delicate experiments have shown that subatomic particles really are entangled it means they can subtly and instantaneously influence each other across space now it seems the same thing is going on inside the Robin's eye when a photon enters the Robin's eye it creates what's called an entangled pair of electrons here's how it works each electron has two possible States for Simplicity I'm choosing to call them red and green now here's the weird thing until I measure it it's neither one nor the other but both at the same time think of the electrons like spinning their simultaneously red and green but by firing a dart I can force the first electron to do one or the other so far it's just a game of chance I don't know what I'll get until I try it so I know my first electron is red suppose I now measure the second electron you'd think I'd have a 50 50 chance of getting red or green after all that's what you'd expect in the normal everyday world but you'd be wrong in quantum entanglement the electrons are mysteriously linked link for example if I get red on the first I always get red on the second it's not a game of chance anymore it's as if the first electron is telling the second one what to do that's why Einstein called it spooky the electrons seem to know that they should both have the same color no matter how far apart they are the really important part is that the two electrons needn't be the same color they can be entangled in a different way so that if the first electron is red the second one is always green seems that this mysterious connection is the ultimate secrets of the quantum Robin's compass because the direction of the Earth's magnetic field can influence the outcome near the equator they may be more likely to be red red but near the pole they may be more likely to be red green and that's the vital factor that finally tips the balance of the Robin's chemical compass variations in the Earth's magnetic field change the way electrons in the Robin's eye are entangled and that's just enough to trigger her compass now finally we can see how something is weak as the Earth's magnetic field can tip that balance one way or the other no no no no no no no no no If the message changes the chemical reaction tips a different way changing the Robin's compass reading suddenly it looks like it's a fundamentally quantum mechanical phenomenon in Birds it would be one of the first if not the first in biology biologists better get used to the weirdness of physics the Robin is navigating by spooky quantum entanglements to see subtle Quantum effects even in a controlled austere environment of a physics lab is really difficult and yet here's the robin doing it with ease these experiments are real and verifiable and yet even though I'm seeing them with my own eyes I still find it hard to believe [Music] thank you bird navigation has brought physics and nature together as the science of quantum biology there's a whole new world to explore but its Pioneers have found that it doesn't just affect Birds [Music] affects every single one of us because the latest experiments say you're doing quantum physics right now and believe it or not you're doing it with your nose foreign our sense of smell is remarkable and quite different from our other senses of sights and hearing among the thousands of scents that we can recognize many of them may well trigger very powerful memories and emotions it's as though our sense of smell is wired directly to our inner consciousness it's also different in another way the other senses of sight and hearing rely on us detecting waves light and sound but our sense of smell involves detecting particles chemical molecules recently scientists have begun to realize that when it comes to our sense of smell something very mysterious is going on for decades biologists thought they knew exactly how our noses sniffed out different chemicals but physicists like Jenny Brooks think there could be a new ingredient in the mix and it smells like quantum mechanics a lot of people think of the sense of smell and of function and the science of affection as being a problem that's been solved and we know all about it and we do know a lot about it we know about the ingredients we know about the equipment that we use to smell but I would argue that there's a little bit more to understand [Music] to understand more I need someone to help me with a smell test and Jim is going to sniff him out [Music] gives off a cocktail of chemicals Jen's nose could detect a single gram of it dissolved over an entire city [Music] so she has no trouble finding the man I'm looking for meet Colin The Gardener a man who's used to smelling the flowers [Music] right then Colin I'm going to put your sniffing skills to the test cool I've got a selection of chemicals here and I want you to tell me what what they remind you of okay I'll start yours easily like a minty minty vapor rub it is yes Menthol yeah but it's that that essence right here's the next one ah you should be able to recognize this one speaking with my daughter um icing sugar vanilla vanilla yeah when our noses detect a chemical they fire a nerve signal to our brains foreign but different chemicals create different Sensations standard explanation for this is to do with the shape of the molecules a conventional theory that goes back to the 1950s says that the scent molecule has a particular shape that allows it to fit in to the receptor molecules in our nose [Music] if it has the right shape it's like a hand in a glove or a key in a lock in fact it's called the lock and key mechanism with the wrong shape it won't fit into the receptor but with the right shape it fits into the receptor triggering that unique smell sensation [Music] different receptors are wired to different parts of our brains so when a menthol molecule locks into its specific receptor it triggers that minty fresh sensation [Music] but the lock and key theory has always had a problem and Colin's next test will show you why okay how about this one quite strong smell oh that's yeah what does it remind you of what does it conjure up what Memories I think Christmas cake yeah yeah that's it yep very yeah Colin identified the smell of marzipan or almonds in fact it's due to a scent molecule called benzaldehyde what I didn't give him to smell was this other chemical cyanide both benzaldehyde and cyanide have the same smell they both smell of almonds but these molecules are both very different shapes so the lock and key mechanism as an explanation for how we smell can't be the whole story so why would two molecules with different shapes smell the same foreign Quantum biology has a head-spinning explanation says our noses aren't smelling chemical molecules [Music] they're listening to them it's not just the shape of a scent molecule that matters let's take a closer look at this model of a cyanide molecule the white ball here is a hydrogen atom and the gray sticks are the bonds that hold it together with the carbon and nitrogen but the reality isn't as simple as that I can give you a better sense of what's going on if we look at this larger white ball you see atoms don't just sit still the bonds that hold them together are like vibrating strings and that gives us a whole new way of thinking about smell the bizarre new quantum theory of smell is all about vibrating bonds [Music] chemical molecules are playing music for our noses imagine a receptor molecule in my nose is like my guitar before it can make a sound a scent molecule has to enter my nose and when that scent molecule is in place its chemical bonds provide the strings and it's ready to be played the receptor molecules contain Quantum particles electrons as they leap from one atom to another they vibrate the bonds of the scent molecule like my fingers plucking a guitar string [Music] what's remarkable about this theory is that it tells us our sense of smell is about the vibrations of molecules or wave-like behavior and not so much about the shape of a particular scent molecule our sense of smell may be much more like our sense of hearing [Music] a particular molecule say that of grass will vibrate at a particular frequency [Music] but a different molecule say that of mint will vibrate at a different frequency [Music] [Music] this would explain why cyanide smells like almonds the two molecules have different shapes but their chemical bonds just happen to vibrate at the same frequency the constant vibration in the Adrian is almost literally like a particle of sound so yeah we're saying that the process of smell could be exactly like an acoustic resonance event it could be very analogous to um hearing and seeing actually but can we really be listening with our noses [Music] a bizarre Theory needs a bizarre experiment to test it here's how it works scientists used a molecule that smells fruity like orange blossom but if the theory is right then I should be able to change its smell by changing its vibrations the molecule contains lots of hydrogen atoms like this bonded to carbon atoms what if I were to replace all these atoms with a different form of hydrogen called deuterium now it won't change the shape of the molecule but it will change the way it vibrates and here's why deuterium is twice as heavy as normal hydrogen and so it vibrates more slowly now different vibrations mean different smells so if I were to make a new form of this chemical all packed with deuterium atoms instead of normal hydrogen it should smell different Quantum biologists found a unique way to carry out this experiment [Music] a smell comparison using the real experts in fruity Aromas fruit flies first the Flies were trained to avoid the modified version of the fruity molecule [Music] to be honest I haven't got a clue how you go about training a fruit fly but apparently you can in the laboratory the Flies had to pass through a kind of maze foreign they were then given a choice [Music] go right for the nice fruity smell or left for the nasty modified version [Music] there could definitely smell the difference [Music] they always preferred the original and turned right foreign fly experiment gives hard evidence that Quantum smell Theory really works But ultimately it works in harmony with the lock and key Theory first the scent molecule fits into the receptor then those molecular vibrations take over incredible as it seems flies humans and dogs may be smelling the sound of quantum biology our sense of smell is fascinating and mysterious as it is but to think that when I encounter a particular scent and that sets off a whole wave of memories and emotions in my mind that is underpinned that it's triggered by quantum mechanics I think makes it even more remarkable the mysterious influence of quantum physics reaches into every corner of the natural world in fact it inhabits the walls of every living cell on Earth because the latest experiments suggest a magical solution to one of the greatest mysteries of nature the miracle of metamorphosis [Music] the transformation of a tadpole into a frog has never been fully explained in little more than six weeks the tadpole breaks down then reassembles in its adult form but the big mystery is how it happens so fast when you think about it there's nothing more extraordinary than a tadpole turning into a frog take its tail for example over a period or several weeks it gets reabsorbed into the body and the proteins and fibers that make up the flesh get recycled to form the Frog's new limbs but for this to happen trillions and trillions of chemical reactions work together breaking molecules forming new ones in a carefully orchestrated dance but the fibers that hold flesh together are very very strong they're a bit like these ropes holding my raft together in order to dismantle the raft I'd have to undo these very tight knots you can think of it like this pole is held together by long ropes of proteins knotted together by chemical bonds the bonds are so strong that they should last for years much longer than the tadpole's entire lifespan so how can it turn into a frog in just a few weeks the explanation involves one of the most important molecules of life tiny widgets in all our cells called enzymes for the enzymes are the actual Machinery of the cell they're actually the The Little Machines inside cells that do the chemical Transformations that are involved in everyday life they're absolutely crucial and the reason they're so crucial is because what they're able to do is to accelerate chemical reactions by enormous amounts let me show you just how quickly enzymes get to work inside this bottle is a substance called hydrogen peroxide you're probably most familiar with it as the chemical used to bleach hair in fact I obtained this sample from my local hairdressers hydrogen peroxide is also produced in the body and it's the job of the liver to get rid of it now the way it does that is using an enzyme which breaks down hydrogen peroxide into water and oxygen now to show you just how quickly this enzyme works I'm going to do a quick demonstration I've got some liver here which I've chopped up in order to release the enzyme now watch what happens when I add this liver mixture containing the enzyme to the hydrogen peroxide watch how quickly the oxygen is released just a hundred grams of liver fired my rocket nearly 20 feet liver enzymes make the breakdown of hydrogen peroxide incredibly efficient it happens a trillion times faster that's a million million times faster than it would otherwise in Metamorphosis it's enzymes that dismantle the tadpole's tail and that means breaking down an incredibly tough protein called collagen collagen is one of the most important proteins for the biological world it's the protein which actually gives that resilience that elasticity to tendons to cartilage and of course to to our skin as well and in the tail of the tadpole it provides the kind of scaffold right that's that supports that structure now when the tadpole is transformed into the Frog what you need to do is to essentially have an enzyme collagenase which will literally snip the collagen down into small pieces and thereby take that scaffold apart but how do enzymes break chemical bonds apart so incredibly fast let me show you why it's a problem only Quantum biology can solve think of it this way all these different parts of the knot are like subatomic particles electrons protons that hold the different parts of the molecule together now to untie the knot enzymes have to move protons about but as you can see this takes quite a bit of effort and a lot of time if there are many many knots to unpick physicists have a fancy way of saying put in effort to get something done they say you have to overcome an energy barrier [Music] okay here's my energy barrier and here's my proton to break up on the part it needs enough energy to get over the barrier the trouble is when we work out how long this would take it's much too slow to break down a tadpole's tail but this is where protons turn into ghosts I wouldn't blame you for thinking that this is an idea that's a clever theoretician has come up with that it's just mere speculation something that we have no proof of but we do it takes place all the time [Music] in the quantum World protons don't have to go over barriers they can tunnel straight through tunneling strikes at the very heart of what is most strange about quantum mechanics it's like nothing we see in our everyday world Quantum particle can tunnel from one place to another even if it has to pass through an impenetrable barrier they're not solid objects like balls in our everyday World they have spread out fuzzy wave-like behavior that allows them to leak through an energy barrier a particle can disappear on one side of the barrier and instantaneously reappear on the other in nuclear physics this effect is a proven fact without Quantum tunneling the sun simply wouldn't shine but I never thought I'd see it in a tadpole it's hard to stress just how weird this process is is as though I would approach a solid brick wall and like a phantom disappear from one side and reappear on the other the most important advantage of tunneling is its speed much faster than if protons go over the barrier as a nuclear physicist Quantum tunneling is my bread and butter subatomic particles like protons do it all the time but what has this Got to Do With Biology the answer is that without Quantum ghosts the metamorphosis of a tadpole would be impossible remember chemical bonds are basically knots tunneling unties them fast have a look at these two knots now on the face of it they look identical but there's a subtle difference this knot has the two short ends of the Rope on the same side whereas this one has the two short ends on opposite sides now you think that wouldn't make a difference but it does you see this knot is very hard to break whereas this one is easy Quantum tunneling turns strong knots into weak ones so in a tadpole the entire collagen scaffold breaks apart easily and finally other enzymes rebuild it in the shape of a frog the quantum tunneling of particles is one of those weird features of the subatomic world that a physicist like me is very familiar with after all it's responsible for radioactive decay and it goes on inside the sun it's the reason why the Sun and all stars shine but to discover that it's going on inside every cell of every living organism on the planet because every cell contains enzymes now that I find truly amazing foreign [Music] Quantum biology casts its spell over every living creature [Music] we've seen that birds mammals insects and amphibians are governed by the strangest laws in science but the most dramatic recent breakthrough concerns the single vital process on which all these forms of life depend conversion of air and sunlight into plants foreign this fine specimen is a laryx decidua or european Larch it's about a hundred feet high and right at this moment passing just this side of the planet Venus is a bullet with this tree's name on it [Music] the bullet is a photon nearing the end of its long journey from the Sun [Music] its ultimate Destiny is to kick start a series of chemical reactions that underpins all life on Earth photosynthesis every second of every day sixteen thousand tons of new plant life are created on Earth and for me it's incredible to think that our existence on this planet depends on what happens in the next trillionth of a second The crucial first stage of photosynthesis is the capture of energy from the Sun it's nearly a hundred percent efficient vast is superior to any human technology but the way that every plant on Earth achieves this is one of the great puzzles in biology when it turned out that Quantum weirdness might hold the answer physicists could hardly believe it was like a revelation it was very exciting because I was used to work on problems that were quite abstract experiments it was I'm a theoretician but I always related my theory to experiments that were very clean in the lab things that you can control but now finding out that the things that I knew can help me to understand better how nature works really I don't know scientifically it was like a an inspiration to My Life as a scientist so I I really as I would say I fell in love with this field textbook biology says the color of green plants comes from chlorophyll molecules inside the living cells they absorb light from the sun this energy is then transferred incredibly quickly to the food making factory at the heart of the cell the entire event takes just a millionth of a millionth of a second when the photon hits the cell it knocks an electron out of the middle of a chlorophyll molecule this creates a tiny packet of energy called an exit on the exoton then bounces its way through a forest of chlorophyll molecules until it reaches What's called the reaction center now that's where its energy is used to drive chemical processes that create the all-important biomolecules of life the problem is the exiton needs to find its way to the reaction Center in the first place or biology can't explain how the exit on does this because of course it doesn't know where it's going it just bounces around like a pinball in a process called a random walk sooner or later it'll pass through every single part of the cell but this isn't the most efficient way to get around [Music] because when the exit on eventually does reach the reaction Center it's by pure charms if the exoton just blindly and randomly hops between the chlorophyll molecules it would take too long to reach the reaction Center and would have lost its energy as waste heat but it doesn't something very different must be going on the vital clue comes from recent experiments that stunned the world of science chemists fired lasers at plant cells to simulate the capture of light from the sun they confirmed the exoton wasn't bouncing along a haphazard route through the cell this original understanding didn't explain what we were observing in the lab so the mystery realizing okay so then what is the explanation for what we are observing in the lab the solution is that plants obey the most famous law in all of quantum mechanics the uncertainty principle [Music] it says you can never be certain that the exit on is in one specific place [Music] instead it behaves like a Quantum wave smearing itself out across the cell [Music] the exit on doesn't simply move from A to B in a bizarre but very real sense it's heading in every direction at the same time it's spreading itself out as a wave so that it can explore all possible Roots simultaneously this strikes at the very heart of what's so strange about quantum mechanics the exoton wave isn't just going this way or that way it's following all paths at the same time that's what gives it such incredible efficiency foreign [Music] if the exit on is trying every route to the reaction Center at once bound to find the fastest possible way to deliver its energy it's hard to express how incredible this discovery seems to physicists like me biological cells are full of the random jiggling of billions of atoms and molecules [Music] that somehow exitons maintain their form as beautiful perfect Quantum waves waves transporting the energy that guarantees life on Earth it opened a whole new scientific path for me and I I really enjoy the fact that to be able to understand fully what is happening there or in the plants you have to interact with scientists that have completely different approaches like biologists and chemists but we all have to come together to actually understand what is the relevance of this the relevance of this so for me this is one of the most exciting parts of this field real scientific experiments leave no doubt strange hand of quantum mechanics has shaped the entire living world it's not a surprise that you should find Quantum tricks being used in biological systems the reason is because they're better [Music] quantum entanglement is normally seen in the tightly controlled conditions of the physics lab but now we know that Robins use it to navigate with extraordinary precision [Music] Quantum vibrations mean our noses listen to chemicals enhancing our perception of the world around us [Music] the living cells of all animals depend vanish and reappear like ghosts beating up the vital processes of life [Music] the synthesis reveals the big picture a shimmering world where Quantum waves capture the sun's energy in an instant sometimes people say ah but physicists have been looking for this for decades well biology has had millions of years the ultra modern science of quantum mechanics is an ancient fact of life for the end of my journey I want to take these ideas to their logical conclusion of course as a scientist any speculations I have have to be backed up by careful experiments so I want to concoct a thought experiment that helps me to answer the biggest biological question I can think of does quantum physics play any role in the mechanism of evolution itself in 1859 Charles Darwin stunned the world with his theory of evolution by natural selection he went on to explain the differences between humans and other Apes [Music] 150 years later there's no doubt that Darwin's theory accounts for every living organism on land and sea but I'd like to explore the latest extraordinary interpretation of his ideas could there be a quantum theory of evolution foreign the snails I'm used to seeing in my back Garden tend to have rather Bland boring shells so have a look at this beauty the patterns on its shell very perfectly match the lines on the stem it's called a banded snail sepia numeralis and the pattern isn't there by accident come and have a look at this less well adapted snails are more likely to be found here this stone is called a thrush's Anvil the song thrush is the snail's main Predator it catches a snail and smashes its shell against the stone to get to the snail now what I can see here is that there aren't many banded snail shells suggesting that its colors camouflage it very well hiding it from the bird foreign [Music] Darwin's theory says that Evolution depends on variation within a species snails with camouflage are more likely to survive and reproduce passing on their shells to the Next Generation so that the species as a whole becomes better adapted so variation the random differences between snails is the driving force behind their evolution now all species evolve and adapt to their environment but the question I'd like to explore is whether quantum mechanics plays a role in this the only way to find out is by scientific experiments so my adventures in Quantum biology finally bring me home [Music] to the University of Surrey here in the Laboratories I'm planning a new analysis of the most celebrated molecule in science deoxyribonucleic acid or DNA stubble Helix holds the genetic code for every living organism it's a remarkable fact that Darwin himself had no idea what created variation in the species the structure of DNA wasn't discovered until 1953 by Francis Crick and James Watson the most famous feature of DNA is of course its beautiful double helix structure but that's just scaffolding the real genetic secret lies in between the four different colored molecules are called bases color code on one side say blue red blue forms a gene the parents pass on to their offspring a gene is a bit like a jigsaw puzzle it fits together like this a full strand of the double helix forms a colored pattern [Music] but the other strand always pairs up the same way a blue base always goes with yellow and green always goes with red because only those colors have the right shape to fit together what Crick and Watson realized was that this provides a mechanism for passing on the genetic code when cells reproduce the two strands of DNA separate ready to be copied but red still goes with green and yellow still goes with blue so bit by bit the cell creates two new strands two perfect copies of the entire genetic code so far there's no genetic variation this new copy is identical to the original but here's the interesting bit during the copying process something very important can happen sometimes mistakes creep in [Music] they're called mutations let's have a look at these two bases here the two prongs that hold them together are subatomic particles they're protons they're basically the bonds between the strands of DNA these protons can jump across to the other side if the strands split when the protons have jumped across they find themselves in the wrong position now this red base will no longer bind to a green base instead it has to bond to a Yellow base slotting this back in we see that now this copy is no longer identical to the original because I have a yellow base here instead of a green one we've brought in a genetic mutation jumping protons would change the snail's DNA it could make a new Gene for camouflaged shells the question is how do protons jump it's my belief that Quantum spookiness can take over now for these mutations to take place the protons have to overcome an energy barrier and if you remember what happened with enzymes well you can probably guess what's coming next protons can behave as if barriers don't exist [Music] the tunnel straight through but does this ghostly effect really happen my colleagues in biology are already looking for the very first evidence of quantum mutations didn't really even know about quantum mechanics so when you tell them that you know particles can be in two places at once they can't say well not in my cells they can't our experiments involves samples of bacteria the first sample is prepared in normal water containing hydrogen nuclei or protons [Music] when the bacteria reproduce we simply count the mutations but if our theory is correct then we should be able to change the rate at which mutations occur remember how we tested the quantum theory of smell what if I replace the proton with its Big Brother the deuteron this is the nucleus of an atom of deuterium now crucially A deuteron is twice as heavy as a proton and this should influence how easy it is for the deuteron to Quantum tunnel quantum mechanics is full of surprises protons tunnel easily deuterons don't these heavier particles are much more likely to bounce straight back so the second sample of bacteria is prepared in heavy water which is full of deuterons our Theory says you should get far fewer mutations and so far the results are extremely encouraging the preliminary experiments that we've done gives us a hint that the mutation rate is indeed depressed and deuterated water we find that it is lowered so my hunches that were right but we'll have to wait a little while before we're sure final proof lies in the future even if we're right Quantum tunneling is a rare form of mutation but our results promise hard evidence for a new explanation of one of the most fundamental processes of life even the nearest possibility of a new Quantum mechanism for evolution itself is tremendously exciting in fact the story of quantum biology is only just beginning what the frog the robin the fruit fly and the tree have shown us Is that real Quantum effects are going on in nature all the time and if there's anything we've learned from the history of quantum mechanics it's this we can never be certain where new discoveries will take us next [Music] Quantum biology is a revolution in science but it's time I got back to the physics department [Music] thank you [Music] [Music] thank you I know I deserve you I know you're my savior but when I observe you you change your behavior so I'm stuck

Channel: Spark

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Keywords: Spark, Science, Technology, Engineering, Learning, How To, education, documentary, factual, mind blown, construction, building, full documentary, space documentary, bbc documentary, Science documentary

Id: K5Po5R-1rgY

Length: 117min 53sec (7073 seconds)

Published: Fri Sep 30 2022