Richard Dawkins - CHRISTMAS LECTURES 1991 - Growing up in the Universe

it's an enormous pleasure for me to introduce to you the hundred and sixty second series of Royal Institution Christmas lectures that have been given in this lecture theatre and during this year since the last series we have in the Royal Institution celebrated the 200th birthday of the what I believe and many other people believe to have been the greatest experimental scientist who ever lived Michael Faraday so I think it's also worth saying this afternoon that not only was he a great scientist but he was also the originator of these Christmas lectures which he started in 1826 and which he himself gave no fewer than 19 times and I thought I would read to you very quickly what he said at the beginning of one of those series of lectures when he stood here and I believe it was in 1854 and he said the following let us consider for a little while how wonderfully we stand upon the world here it is that we are born and bred and live and yet we view these things with an almost entire absence of wonder to ourselves respecting the way in which all this happens now that was the reason for the Christmas lectures in Faraday's mind it was to awaken wonder and we're going to take up that theme again this year because dr. Richard Dawkins the reader in zoology from Oxford University is going to tell us how you and I stand upon this world and how that all comes to happen because he's going to explain to us how living creatures many kinds of them increase including you and I have evolved on the surface of the earth we are very happy once again at the Royal Institution to acknowledge the help that we have had in preparing these lectures from Shell UK and Shell international who have given this valuable sponsorship and I would also like to take the opportunity to say that we are organising gain a competition this year based on the content of the lectures so if you would like to participate in the competition you will find the address to send your entries to displayed at the end of the lecture now it only remains for me to introduce to you dr. Richard Dawkins who is going to give the 1991 Christmas lectures of the Royal Institution on waking up in the universe hello thank you very much for coming I'd like to begin by asking you to do something for me would you please put your hands to your head and very gently feel your own head now that might seem like a very easy thing to do but I can assure you okay put them down now I can assure you that a man-made instrument that did that would be a very very difficult thing to make it a very very expensive thing to make as your arms go up they're precision instruments in your muscles are monitoring the exact position of all your muscles thousands of sensory endings in your fingers are feeling the exact texture of your hair the shape of your ears the shape of your skull your brain is measuring the width of your skull with the greatest of precision if a human factory were to manufacture an instrument a robot arm capable of doing that it would cost something in the region I would think of a hundred million pounds now think about what is between your hands when you do that your brain the brain is a kind of computer but it's a computer such as no human factory has ever turned out if we ever do succeed in making a computer with the performance of a human brain I would guess that the research and development costs would be in the region of thousands of millions of pounds yet heads like yours and hands like yours are manufactured daily millions of times over a woman can do it with no research and only nine months development and only a little help from a friend life makes the wonders of technology seem commonplace so where does life come from what is it why are we here what are we for what is the meaning of life there's a conventional wisdom which says that science has nothing to say about such questions well all I can say is that if science has nothing to say it's certain that no other discipline can say anything at all but in fact of course science has a great deal to say about such questions and that's what these five lectures are going to be about life grows up in the universe by gradual degrees evolution and we grow up in our understanding of our origins and our meaning of all the world societies the majority have practiced some form of ancestor worship this is a totem of one particular cult of ancestor worship now I'm not going to encourage you to worship your ancestors I'm not going to encourage you to worship anything but it is true that ancestors hold the key to understanding the meaning of life you might think it's easy enough to be an ancestor it's easy enough to reproduce so relatively easy but to become an ancestor you've got to have descendants alive many generations hence and that's more of a tall order we can think about it by going back to one of the simplest sorts of animals a bacterium right back at the beginning of life and think about how many bacteria there would be after say 50 generations of reproduction we're going to illustrate this by folding paper I wonder if I could have two volunteers to fold the paper right there and yes there come down here please and take the paper from Dyson right now every time you fold the paper that's going to represent one generation of reproduction so we start with one bacterium that's one thickness of paper now fold it guess if you both go to the same end it might be easier now we've got two that's right please sit down there that's why I fold it and then fold it across this way thank you and just go on folding it until you've done it 50 times so what we got to now for for bacteria right 816 thirty two more clutch do anymore right that's probably all right it looks they're not going to make it we're going to have to resort to mathematics to calculate how thick that paper would be okay thank you very much do sit down in every generation of course the thickness of the paper doubles so we go to 4 8 16 32 64 and so on we go on multiplying by 2 50 times after we multiply by 2 50 times what have we got we've got a very big number indeed we've got in fact a thousand trillion at one with 50 knots after it the sheet of paper is a tenth of a millimeter thick if you multiply that by a thousand trillion you end up with got it written down here a hundred million kilometres the thickness of the paper would take us out to the orbit of Mars the number of bacteria after a mere 50 generations is that but 50 generations is nothing to bacteria they can get through 50 generations in a day after about a week bacteria the number of bacteria would be more than a billion times the number of atoms in the known universe well that's called exponential growth what mathematicians call exponential growth we'll come back to it needless to say it doesn't happen to the same extent at least after a point natural factors come to regulate the size of the population of bacteria our original assumption that it was easy to become an ancestor was wrong only an elite become ancestors you can do the same sort of calculation by the way for ourselves or for elephants as Charles Darwin did and it just takes a little bit longer but the same idea is there after a fairly short number of years you'll find that the entire universe is filled with elephant flesh or human flesh or whatever it is so it follows that most organisms that are born must die without becoming ancestors without becoming distant ancestor only an elite are destined to become ancestors or some people don't like the word elite but I just mean that it won't be all luck which ones end up ancestors the ones that are going to be ancestors will tend to be the ones that are good at it they'll tend to be the ones that have what it takes what have what it takes to survive to get a mate to reproduce to avoid being eaten to find food to be good parents and so on that's really just a way of putting Darwin's theory of natural selection because we that are left we that survive have will have inherited the genes of a long line of successful ancestors we have inherited whatever it took to make them successful as ancestors but for the moment I want to emphasize something else which is that we are lucky to be alive we're lucky to be alive because it would have been so easy for our ancestors not to have been here it would have been so astre nama CLE probable that somebody else would have been here rather than us and we're lucky to be alive for another reason think about it this way the universe is about fourteen thousand million years old that's 140 million centuries some 60 million centuries from now the Sun will become a red giant and engulf the earth so there are about 200 million centuries from the origin of the universe to the end of the world now of the hundred and forty million centuries since time began every one of them was once the present century and of the 60 million centuries to the end of the world every one of them will be the present century the present century is a tiny spotlight inching its way along a gigantic ruler of time everything before the spotlight is in the darkness of the dead past everything after the spotlight is in the darkness of the unknown future we live in the spotlight of all the 200 million centuries along the ruler of time 199 million nine hundred ninety nine thousand nine hundred ninety nine centuries are in darkness only one is lit up and that's the one in which we happen by sheer luck to be alive the odds against our centuries happening to be the present century are the same as the odds against a penny tossed out at random on the road from London to Istanbul happening to fall on a particular end well in spite of those odds you may have noticed that we are as a matter of fact here and it really of course it's not surprising we're here because we're the ones doing the calculation if somebody has just done the calculation that we've just done then that somebody of course has to be alive nevertheless I do feel about the lucky to be alive and for another reason to now the smoke going into the beam represent stars each particle of smoke represents one star and you can think of a beam as a gigantic searchlight beamed out from space and signaling from our planet in the hope that somebody else on another world will pick up the message we don't know how likely it is that there is anybody up there we can say that if our message does hit another planet then almost certainly it will be so far away that if those people up there had a telescope looking back at us then what they would be seeing is not us at all but the dinosaurs that was here 65 million years ago or in other words our message will reach people millions of years into the future people vary in their estimates of how much life there is likely to be how likely there is to be life on other planets some people think that some scientists think that as many as 10 million technologically advanced civilizations are out there other people feel that this life here on this planet is the only life that there is but even on the most extremely optimistic estimate it's still true that most of those worlds out there are going to be deserts most of them are not going to have any life on them at all nor even any possibility of life on them at all now imagine a spaceship full of sleeping perhaps deep frozen explorers would be colonists of another world perhaps they're the last population of Earth despairing that earth is about to be destroyed sending out a colony to look for another planet anywhere in order to carry on humanity imagine that the spaceship turns out to be almost unthinkably lucky it does chance to arrive at one of the very very rare planets capable of sustaining our kind of life a planet of the right temperature with oxygen and so on the passengers wake up and stumble out into the light and they see a beautiful world of waterfalls green leaves mountains colored animals and bird-like creatures flitting about can you imagine how it would feel if you woke up perhaps after a hundred million years of sleep in a spaceship and found yourself on such a world a whole new world a world that you such as you could live on a beautiful world you'd surely bless your luck in arriving on such a rare world walk around in a daze a trance unable to believe the wonders that met your eyes and ears well this will almost certainly never happen to us and yet in a way it's just what has happened to us we have woken up after hundreds of millions of years of sleep admittedly we didn't arrive by spaceship we arrived being born but the wonder of the planet the dazzling surprise of it is the same whether we arrive by spaceship or by birth canal we are amazingly lucky to be here privileged and we must not waste that privilege here it seems to me lies the best answer to those narrow-minded people who are always harping on about the use of science the founder of these Christmas lectures Michael Faraday was once asked by the then Prime Minister Sir Robert Peel what was the use of science sir Faraday replied what is the use of a baby she says her name's Hannah Faraday said what is the use of a baby and I've always thought that what he meant by that must be that a baby has such potential it may not be able to do very much now but oh it will be able to do a lot but it's also possible that what Faraday meant was that there's no point in bringing a baby into the world if all that it's going to do is work to go on living to go on living and work to go on living again if that's all the point of life and what are we here for there's got to be more to it than that thank you very much some of life must be devoted to living itself some of life must be devoted to doing something worthwhile with with one's life not just to perpetuating it this is of course how people quite rightly justify spending taxpayers money on the arts and on conserving rare species but sometimes when we justify academic science on those grounds people get rather Philistine and say things like oh so you think the government should spend money on your scientific research because your research is fun for you do you fun isn't really the right word is it after sleeping for 140 million centuries we have finally woken up in the universe we've opened our eyes on a wonderful planet filled with color teeming with life before very long we shall have to close our eyes again finding out about the universe in which we've woken up answering questions like what are we doing here what is this universe in which we've woken up what is life and what if anything is it for surely the enterprise that answers questions like that science deserves a better title than fun put like that doesn't science sound to you like just about the most worthwhile way in which you could possibly spend your short time in the spotlight now of course if you spent all your time wandering around the world gasping and everything and saying how wonderful how amazing I woken up after a hundred million centuries what a trip people would think you were a bit odd and you might even get arrested we do of course have an ordinary life to get on with we do have a living to earn we've got to earn our living being a solicitor or laboratory cleaner or something like that but nevertheless it is worthwhile also from time to time shaking off the anesthetic of familiarity and awakening to the wonder that is really all around us all the time so how are we going to shake off the anaesthetic we can't actually go to another planet but fortunately we don't need to because we can go to regions of our own planet which are so unfamiliar that they almost might be another planet this is another planet this is Jupiter it's a fantasy picture of Jupiter conceived by the astronomer Carl Sagan and he's imagining life-forms that might live in the upper atmosphere of Jupiter called floaters if there were life-forms in Jupiter they would be called Jovians so let's use the word by Jovians for creatures on this earth that are so odd that they might almost be from another planet here for instance is a deep-sea fish you would have to go on a long journey in a submarine on a diving suit to see that fish this is exactly the same species of fish the only difference is that this has just had a meal and that hasn't that's looking for a meal as you can tell from its ravening jaws these creatures look pretty monstrous to us I suppose by their standards we might be thought monstrous this one is another deep-sea fish this has a luminous law made by bacteria luminous bacteria and it uses this as a bait to lure prey into its vicinity it then slams its fishing rod down into the vicinity of its jaws opens them and gulps in the prey a very weird by Jovian creature we don't even have to go to the deep-sea as a matter of fact to see pretty weird creatures I was once attending a lecture by a colleague who worked on octopuses and he said the fascination with octopuses is these are the Martians and he meant that look at this this creature could easily be from Mars couldn't it watch the color change that creature that cuttlefish is not an octopus it's a cuttlefish is changing color at will look at the waves of color falling over it that's not shadows falling over from outside that's internally controlled by the animal by its own nervous system it's registering emotion signaling to other creatures others of its own species by Jovian creature we don't even have to go to the sea at all these are all insects they all have the same basic insect body plan which they inherited from a common insect ancestor which lived about 350 million years ago they all look like insects because they've inherited those attributes they all have a head thorax and abdomen but in this case it's enormous ly elongated to look like a stick here the same body is flattened out in this bug again the head thorax abdomen three pairs of legs and Tennie wings here butterflies the same basic body plan pulled and stretched kneaded into different shapes but basically the same shape they've never quite shaken off their ancestral influence but we were talking about shaking off our anaesthetic of soporific familiarity and another way to achieve the illusion of waking up on a distant planet is to shrink ourselves to go on a different kind of journey to a much smaller scale than we're used to this is a dust mite it's a sort of thing that you've met often in the carpets of your own home but didn't know it it's hugely magnified by an instrument like this which is a scanning electron microscope and we can use the scanning electron microscope just as though it was a telescope pointing at some distant planet so strange are the sights that it shows us I think we have a volunteer to work the electron microscope now your name is Louise do sit down Louise now on the screen at the moment we have what looks like a jungle we can think of it as a jungle on another planet now you know how to work the joystick and navigate around you also know how to zoom out and in what about zooming out and seeing what this jungle really is okay let's go slowly now there's some curious rounded objects there go further to little patches of rounded objects go further go on right now I think what we're seeing is the head of a mosquito there are the compound eyes lots of different facets of the compound eyes on either side in the middle are the sockets of the antennae zoom out further and again and there's the whole head you can see the whole round head with the sockets for the antennae and the rounded compound eyes with all the different facets now perhaps we can navigate to a different insect yes the machine has been pre-programmed to move now to a different part of this strange landscape and I hope we're going to see something else in a minute what's this here looks like another jungle so let's move around and explore what we think it is I can't see anything yet I'll wait a minute let's zoom out a bit and see whether we can see better then again again now that's looking like something I think that's a pair of wings don't off to the left side isn't it so I think that might be the thorax of an insect of some sort let's try moving that way and see what we see other way let's eat it up a little bit that's right it's the abdomen of a bee I would think go on more now what's that something curious poking out try and steer your way around so that's in the middle other way and then down a bit now zoom into it keep I'll keep staring shall I assume in need a bit of focus I think let me do that looks to me like the head of something else zoom out again what that is as a matter of fact is a tiny parasite thank you very much indeed Louise it's a tiny insect parasite called a strep sipped tea room which is parasitizing Abbey and what you saw was the strep zip Terim poking out below the armor plating of the be there there's it's compound eyes there's its body and that is one armored plate of the bee so we've been on a journey using the scanning electron microscope to the world of the very small and that's another way of capturing the strangeness of our own world yet another way is to go into our own bodies and look at the detailed structure of our own bodies for example this is a picture of a human brain and each of these black things is one brain cell and you can see how many there are they're only a tiny fraction of them staying to be seen here and the bewildering forest of interconnections between them the total length of nerve cells in a human brain if laid end-to-end would stretch right round the circumference of the world not just once but 25 times well that's not an itself a very interesting fact for one thing if you actually did that and you sent a message from one end of this vast great nerve to the other it would take about six years to get to the other end of the nerve what's truly impressive about the nervous system is not the sheer number of elements but their connectedness the complexity of the connections is truly awesome here is just four or three nerve cells and these are the connections between them there are about 2,000 wires connecting each nerve cell to each other nerve cell so the total number of connections in the brain must be about 200 million million to put that into perspective if we assume that each of those connections is equivalent to one switching unit of a computer this gives the brain about 10 million times as many switching elements as a typical desktop computer brains are impressive because of the number and connections of their cells but there are lots of other different kinds of cells in the body and they all have the same basic structure inside this is a typical animal cell model of a typical animal cell and it's not just a bag of juice it's filled with membranes it's got a structure and internal structure each of these blue things here is a membrane and every cell has them in large amounts such that the total area of membrane inside a typical human body is about 200 acres that's a good sized farm what are they all doing well they aren't just sort of stuffing or folded wadding those membranes in many cases are chemical factories particularly the ones in these bodies called mitochondria the orange ones here they are made of membrane and in those membranes in every bit of those membranes is going on chemistry they are chemical factories this here is a map of the chemical reactions in every cell mind-bogglingly complicated stupefyingly complicated every one of these arrows is one chemical reaction yet all of that all of that is going on all the time inside the membranes of every mitochondrion in every cell in you and the number of mitochondria in which that's going on all the time is such that if you laid all your mitochondria end-to-end they would go around the world not once not 25 times but 2,000 times in the nucleus of the cell right in the center is the DNA the DNA the magic molecule the molecule of life the most important molecule in the world that molecule conveys the information from generation to generation about how to build a body the total amount of information is such that if you were to eat a steak when you eat a steak every time you do it your teeth are mangling are shredding the equivalent of a billion copies of the Encyclopedia Britannica that's the kind of destructive work you can do with your teeth hemoglobin is the molecule that carries oxygen in the blood can see it the shape of it is complicated it's very complicated and what's remarkable about it is that the same shape is going on all the time in all the different molecules that you can think of the hemoglobin molecule as rather like a truck forking for carrying oxygen each hemoglobin molecule drives around carrying oxygen from one part of the body to another it's a vehicle for carrying oxygen but I've just got six little trucks here what's remarkable about hemoglobin is that the number of them in your bloodstream is not just six it's six thousand million million million they're all very complicated they all look like that they all look exactly the same as each other and they're all being destroyed and new ones being created all the time in your blood at a rate of 400 million million every second another way to shake off the anesthetic of familiarity another way to experience something a little bit like going to another planet is to go on another kind of journey backwards in time on our own planet the best way to do this would be with a time machine but even Bryson Gore and the Royal Institution can't lay on a time machine for us so we have to use fossils one of the most difficult things to grasp about fossils like this trilobite here is how old they are you could have no conception how old that animal is in case that sounds patronizing let me rephrase it I can have no conception how old it is I can tell you in words how old it is it's about five hundred million years old perhaps a bit more but to tell you in words and ready to understand what that means is another matter our brains have evolved to comprehend the timescales of our own lifetimes we can understand seconds minutes days weeks years even centuries we can understand when we come to millennia thousands of years our spines start to tingle epic myths like Homer's Odyssey tales of the Greek god Zeus and Apollo and the others the Jewish heroes Moses and Joshua and their God Yahweh the ancient Egyptians and the Sun God raah these all give us an eerie feeling of immense age we feel that we are peering back into the mists of antiquity yet on the time scale of this fossil those mists of antiquity don't even count as yesterday this is a cuneiform tablet from Mesopotamia somewhere around the seventh century BC its BC by cuneiforms a bit rusty yes it's a legal document on the sale of some land near Nineveh yes that's right this here is another thing that gives one the same feeling this is a Bronze Age Warriors mask that was dug up in the last century by a famous 19th century archaeologist Schliemann and he said I have gazed upon the face of Agamemnon now this matter fact isn't wasn't the face of Agamemnon but he thought it was and to him that was his way of being awed being awed at the immense age of it he was feeling himself going back through those mists of antiquity let's try to get a feel for how old things really are and then try to fit our trilobite onto the same scale I'm going to take one pace to represent a thousand years I'm going to start at the time of the first Christmas so this little broach here dates from the time of the first Christmas naught II see if I take one pace I'm back at a thousand BC about the time of the tablet that we've just been looking at about the time of King David another pace 2000 BC and this Bronze Age axe head another pace 3,000 BC about the time just before the building of the Egyptian pyramids another place this piece of pottery 4000 BC about the time when Archbishop Ussher calculated the beginning of the world and Adam and Eve but we've hardly started yet you've got a long way to go walking from one side of the green bench to the other we've gone back to 4000 BC this is Homo habilis she or someone very like her is our direct ancestor she lived 2 million years ago to get back to her time you would need on the same scale of pacing to go about 2 kilometers quite a long way now we've got some more ancestral portraits and I'm going to call them up in order so will the person who's standing who's sitting behind Australopithecus the first one please stand up thank you that's Australopithecus he is probably a direct ancestor of this one he lived about 3 million years ago so we'd have to walk three kilometers to get to his time now the next person please thank you that's Rama Pythias that would be possibly an ancestor not just of us but also of all the great apes and he's about 14 kilometres away on our scale the next one please thank you that's an early primate and that to get to that one you'd have to walk to about hemel hempstead to get to that to the age of that creature the next one please an early mammal about lutein that distance next one an insectivore with the little with a little millipede in its jaws maybe Newport Pagnell the next one please that's an early mammal-like reptile and its distance is about Manchester the next one an amphibian middlesbrough and the next right that's a fish just coming out of water just leaving the water and coming to the land and its distance is about Carlisle and I've left do sit down now thank you very much those are all your ancestors this one is the oldest of all the ones we've got here it's about the same age as the trilobite that we started with they might have met this is pacaya and in order to find its age you would have to slog it out all the way from here to Glasgow and remember that our perception of historical time back to the mists of antiquity is a couple of paces across this green table and even with pacaya we haven't finished because there are lots and lots more ancestors before-- pacaya if we go back to the origin of life to the first bacteria we're going back three and a half thousand million years and in order to pace our way back to that age we would have to march all the way from here to Moscow these are the sorts of ages that we have to understand if we're going to understand evolution and our brains are not equipped to do so when we were looking at our ancestors around there we could be misled because it gives the idea that evolution is marching inexorably towards a climax the climax being of course us and that's not the way it was evolution was marching in thousands and millions of different directions at once this here is not the wrong institution Christmas tree it's the tree of life and it's a representation of a tiny tiny fraction of the lines of evolution that there were the origin of life is down here this is the first thousand million years of life here coming up here now each of these branch points represents an ancestor of whatever lies up the branches from it so for example these there are the plants this I should say is definitely not to scale I've just noticed so nevermind dad forget everything about scale on this on this tree what is correct is the order of branching but not the detailed distances of the branches so this branch represents the plants those two are closer cousins of each other than they are of that one this branch represents the primates with gorillas and a human their common ancestor is their this branch here represents carnivores and there's a branch with a lion and a tiger and their common ancestor there which is more recent than the common ancestor of the bear and the dog but that's the common ancestor of all the carnivores here we have zebra and a rhino not to scale and you can see that they are more closely related to one another then either of them is to these cloven hoofed animals the Bison the sheep and the goat the sheep and the goat have a very recent common ancestor their cousins the Bison has a slightly older common ancestor here we have two insects a fly and a grasshopper they have an ancestor there and then they have they share an ancestor with the spiders a little bit earlier on this is a tiny fraction of the number of animals and plants that there should be on this tree this tree should have some 10 or 20 million twigs around there and the ancestors of all these animals are in the middle of the tree going inwards like that so all the ancestral portraits that we've just seen around there they would be laid out along there what we're looking at here are all modern animals all those animals are cousins of one another and they're cousins of us these hamsters here are also cousins of us everything that that's alive today is a cousin of us these fish are our cousins this elephant these elephants these are by the way extinct elephants are our cousins this swift is our cousin we know that they're all our cousins because we know that they all have the same DNA code the DNA code of all living things alive today is the same and that is too improbable to have come about unless we have an ancestor we're all descended from one remote ancestor which lived probably between three and four thousand million years ago and we are therefore all cousins if we ever meet life from another planet the creatures from there will not be our cousins they will have evolved entirely independently they won't have DNA would be my guess however I would be prepared to say that they are likely to have quite a lot in common with us simply because there's a lot of similar problems to be solved in living and those problems are likely to be the same all over the universe so although they won't have DNA they'll have something very similar in function it'll do something very like DNA and it'll work in a similar way to DNA I'd also be prepared to put my shirt on the bed that they will have evolved by the equivalent of Darwinian natural selection if we're ever visited by life-forms for another planet they will certainly have evolved the power to think and do science otherwise they couldn't have got here and their science is bound to be essentially the same as our science this is because the principles of physics and chemistry are the same all over the universe they'll have the same values of the constants or constant PI as we have they'll have Pythagoras's theorem they'll have relativity although they weren't attributed to Einstein they'll probably find us pretty childish but they'll be quite kind about our science they'll Pat us on the head and say well what you know about the universe is pretty much correct you've got a lot to learn yet but you're doing fine keep it up that's what they'd say if they were talking to our scientists what if they were talking to our best lawyers or literary critics or theologians I doubt if they'd be so impressed they might be they're anthropologists the equivalent of their anthropologists might be of might be interested in us but they would be bound to notice that our cultural beliefs are very local and parochial not just by their standards they're universal standards they certainly would be but even by our own standards because what people believe on our planet depends so much on whereabouts on the planet they happen to be born which is a fairly odd thing the Adam and Eve myth is believed by a lot of people in certain parts of the world but if you go to other parts of the world you'll find them believing very different myths this is a Hindu myth which is also very beautiful and we have there are other Hindu myths as well this is another Hindu myth myth of churning the milk of the ocean with a churn gods and demons churning an axle with a turtle on the bottom and out of the ocean came as butter comes out of milk came all living creatures these creation myths are very beautiful but they're all different from one another and they can't all be true and it's very odd if people believe simply what the other people in their own country happen to believe just because they're in that country look how scientists handle their disagreements now take a particular disagreement why did the dinosaurs go extinct there are various theories this is the theory that a comet or meteorite hit the earth and caused a catastrophe that drove the dinosaurs extinct and a lot of scientists believe that a lot of scientists on the other hand believe that a virus killed the dinosaurs and another lot of scientists believe that the mammals arose and yet the dinosaurs eggs now no doubt there's something going for all those theories the point is that different scientists believe them and the reason why they disagree is that there isn't enough evidence yet everybody knows everybody agrees about what sort of evidence would be needed in order to make them change their mind but suppose science work like creation myths or like languages here we have a map of world languages in this red area English is spoken there Spanish is spoken there Russian is spoken and it's quite natural that you should be able to plot a map like that the people should speak the language of their country but what if scientific theories were like that what if we had a similar map of the distribution of scientific theories suppose in the red area everyone believed the meteor theory of the dinosaur extinction and in that area everybody believed the var and in that area everybody believed the mammals eating the eggs theory wouldn't that be a pretty silly sort of science imagine the scene to scientists arguing and one of them says I believe that the dinosaurs went extinct because a comet hit the earth why do I believe that because that's what my father and grandfather believed and that's what people in my country have always believed but I believe that it was a virus that drove the dinosaurs extinct why do I believe that because my father and grandfather believed it and that's what people in my country have always believed or suppose the conversation went like this never mind the evidence I just know that a comet struck the earth because it's been privately revealed to me that a comet struck the earth but I just know that it was a virus because I just know it because I just know it because I have faith that it was a virus if you overheard conversations like that you'd think they were pretty odd scientists wouldn't you you'd see no reason to believe any of them growing up in the universe partly means evolving from simple to complicated inefficient to efficient brainless to brainy but it also means growing out of parochial and superstitious views of the universe growing up to a proper scientific understanding of the universe based upon evidence public argument rather than Authority or tradition or private revelation growing up means trying to understand how the universe works not copping out with supernatural ideas that only seem to explain things that actually explain nothing well you might say can we really afford to be snooty about the supernatural after all many of us have probably had uncanny experiences that sound like telepathy we perhaps dreamt about somebody with whom we hadn't thought of for years and then the very next day we had a letter from them and we think what an amazing coincidence there must be something supernatural it seems so spooky that's a supernatural explanation what would a natural explanation of an event like that be well what we've got to do is to come to a proper assessment of how likely it would have been that this could have happened anyway by sheer luck and there are ways of doing that and we can run a very simple experiment here on a very small scale they're going to do it by tossing pennies it may be that somewhere in this audience is somebody who is psychic and is capable of willing a penny to come down heads or tails and what we've got to do is to identify that psychic individual so Bryce is going to toss a penny and I want to I'm going to ask everybody on this side of the will forget about the gallery because I can't see them up there everybody on this side of me here is to will it to be cut to come down heads really think of it coming down heads try to make it come down heads we will try to see whether the psychic individual is that side or on this side everybody should will it to come down tails okay so off we go so tails right so if we've got a psychic individual it must be on this side now would everybody on this side then please stand up we're going to try to do this by elimination now everybody on this side of the aisle will it to become heads everybody on this side of the aisle will it to come down tails heads heads sit down please stay standing up now it's got a bit of a problem here let's say everyone from behind the row that was holding up the ancestral portraits should will it to come down heads and everyone from the ancestral portraits downwards tails toes right the back rows then sit down please right now we're narrowing it down with how many tosses are we done three right now one two three four let's say the back two rows of those standing will it to be heads and the remainder tails tails back two rows sit down please right now one two three four five six month is it okay we'll make it simple the back row heads and the front two rows tails toes back row sit down right back row heads front row tails tails tails now right let's say but from coca-cola to the left heads and the other one tails heads heads down please no coca-cola stand not right right um heads tails heads heads right well done I don't know how many tosses that was but congratulations let us suppose that it was eight it was was it right now what's your name who got it yes Johnny yes welcome Donnie now the question is is he psychic he managed to he managed to get it right eight times in a row and that's pretty impressive but of course there's absolutely no evidence whatever that he's psychic he did indeed think about heads and tails and it did come down the right way but if you think about how we set the experiment up with successive divisions he could have thought about ham and eggs and it would have given the same result it had to come out because of the number of people here it had to come out that somebody was apparently psychic now we've only got a few hundred people in this room but if we could do this with a million people or two million people we could have gone on tossing pennies for a very long time at the end of that time we'd have got a very impressive result now when people write into the papers with uncanny experiences it's just like that because the circulation of a tabloid newspaper is up in the million and if only one of them has to write in then you can see exactly what happens there's got to be somebody out there having an uncanny experience at this very moment and it means absolutely nothing so don't whenever you hear a story about uncanny spooky telepathic experiences think about this experiment and think about how likely it would be to come about anyway put your trust in the scientific method put your faith in the scientific method there's nothing wrong with having faith I'm going to move Faraday out of the way nothing wrong with having faith in a proper scientific prediction this is a heavy cannonball I understand here and I'm going to release it and it's going to come it's going to go over there it's going to come roaring back towards me and all my instincts are going to tell me to run for it but I have enough faith in the scientific method to know that it's going to stop just about an inch short or perhaps less of my head so here goes I felt the wind of it the Nobel prize-winning scientist Sir Peter Medawar in a book written jointly with his wife wrote the following only human beings guide their behavior by a knowledge of what happened before they were born and a preconception of what may happen after they are dead thus only humans find their way by a light that illuminates more than the patch of ground they stand on well that's all for today in the next lecture I shall be turning to the problem of design and the difference between genuinely design things like that electron microscope and apparently designed things that are not really designed like this elephant and like this Swift thank you very much Oh Oh

Channel: The Royal Institution

Views: 132,263

Rating: 4.894628 out of 5

Keywords: Science, Ri, Royal Institution, Biology, Science Communication, Evolution, Evolutionary Biology, Origins, Animals, Dawkins, Darwin, Richard Dawkins, Christmas Lectures, Creationism, Butterflies, Theory of Evolution, Experiments, Archive, Royal Institution Christmas Lectures (TV Program)

Id: dw4w1UsOafQ

Length: 57min 36sec (3456 seconds)

Published: Sat Apr 13 2013

Reddit Comments

[u/AluminiumAwning]

Does anyone know if the 1989 lectures are available to stream? I seem to remember they were about audio and video technology.