[Elizabeth Fee:] Good afternoon. My name is Elizabeth Fee and I'm chief of the History of Medicine Division here at the National Library of Medicine. And I am delighted to welcome you to the History of Medicine seminar series. We have a very special speaker today, and I especially like to welcome his good friend, Doctor Elias Zerhouni. So our speaker today is Doctor Bulent Atalay, [PhD] who received his early education in England and the United States, attending Eton in the UK and Saint Andrews School in Delaware. He went into physics by accident when a secretary in the college admissions office misread his career aspirations as physicist. Instead of physician. But he found he did have interests in physics. He received his professional training, BS, MS, MA, PhD, and postdoctoral work in theoretical physics at Georgetown, UC Berkeley, Princeton, and Oxford University. Now he is Professor of Physics at the University of Mary Washington and Adjunct Professor at the University of Virginia. And he is a member of the prestigious Institute for Advanced Study at Princeton University. He is an accomplished artist, and he has presented his work at one-man exhibitions in London and Washington. And has and his two books of lithographs can be found in the permanent collections of Buckingham Palace, the Smithsonian and the White House. Four years after the release of Math and the Mona Lisa by Smithsonian Books in April 2004, the book has already appeared in 11 languages. With one more Polish still pending. Doctor Atalay has just completed collaboration on a new book, Leonardo's Universe: the Renaissance World of Leonardo da Vinci. Would you like to stand and just hold up the book? -- with Keith Wamsley. And this book is about to be released by the National Geographic Books on January the 6th, 2009. So this is, in a sense a little birthday party for the new book. Doctor Atalay's title for today is Leonardo and the Unity of Art and Science. Let me just make another announcement, which is that the next History of Medicine seminar will be held on Wednesday, January 14th at 2:00 o'clock in the Lister Hill Visitor Center. And Doctor Gail Kern Paster of the Folgers Shakespearean Library, will speak on The humor of it: bodies, fluids, and the history of medicine in Shakespeare. So you're most welcome to attend any and all History of Medicine seminars. And with that, Doctor Atalay. Please help me welcome. [Applause] [Footsteps] [Dr. Bulent Atalay:] I'm flattered. I'm honored to be here. To see Doctor Zerhouni is even greater honor. He was my son's advisor. My son did an MDPHD at Hopkins some years ago -- 12 years ago he graduated. And among Dr. Zerhouni's 2 Lauterbur Prizes, one of them I think is with Michael. Right? Now Michael is at Brown University Medical Center and unfortunately he's happy there, because I'd love to have him come here, or to to Hopkins, where we'd be closer to him. This lecture has many legs. I do art and I do theoretical physics. I, my book of lithographs of historic Virginia were given to the Queen when I was a postdoc at Oxford in the early 70s. And there's a way you address the Queen, you say, Dear 'Ma'am,' and Sir. MA apostrophe, AM and Sir. And you must sign off the letter with I have the honor to be your obedient servant. My books were given to the Queen by the Nixon family. My book of lithographs of Historic Virginia and the Queen wrote to the Department of Theoretical Physics at Oxford. Everyone's in the physics department was impressed. It said "we were enchanted by your last book. Would you be interested in doing one of England?" Well, I was there to do serious physics, but when the Queen commissions you, you have to sort of give at least the weekends to a project like that. A couple of years later, my book of lithographs, Oxford and English Countryside, was published. And by then I was back in the States. I was at Princeton at the Institute of Advance Study. Another letter arrived from the Queen. She had received the 1st 5 copies off the press and she said, "Dear Professor Atalay, we were enchanted by your last work." I think it was a form letter. It was exactly the same wording. "Please send us a copy of your next work." My Israeli co-author and I. One of my closest friends, we immediately bundled 10 papers we had done together and we shot it off. Shot the collection off to her as the perturbation theory for projected states. She wasn't much impressed with theoretical physics, but this newest book, the National Geographic book, I will send to her as soon as -- it's released. Over the weekend they had advanced sales at the Aspen Institute and the 1st 50 copies that were sent there were immediately purchased. And if anyone wants these nice business card bookmarks that the National Geographics invented, I'll be happy to sign them for books, but they won't release them till January. [paper card rustle] It was over the years. I did, oh, the story I just told you about the Queen. It has a precedent. 150 years ago. Until 150 years ago, Oxford dons were not allowed to marry. It seems they had misbehaved 300 years earlier and the king had passed an edict, made a decree these clowns don't marry. Then in the 19th century, the mid 19th century, Queen Victoria changed the law and she said henceforth the - the dons, the clowns may marry. Well one of the dons A fellow named Charles Lutwidge Dodgson was never married. He was a professed bachelor. He was also he was a mathematician, a pioneer photographer, and his hobby was making up stories for children. Maybe some of you in this room know about Charles Lutwidge Dodgson. At the behest of a friend, he published a book. He changed his name to to Lewis Carroll. And the queen got a hold of Alice in Wonderland. She wrote to Charles Lutwidge Dodgson "We were enchanted by your last book. Please send us your [?]" [ Laughter ] As she received a book in abstract algebra. So. So even the bizarre does sometimes repeat itself. I had an ignominious beginning to my art. Actually I was -- my father was a military attaché from Turkey to London in the late 40s. I was a little kid, and I used to draw and paint as a child, and the one thing I knew about Leonardo was his pronouncement that the eyes were the windows to the soul. Now we lived in the Curzon house. The Lord Curzon had been a very prominent English statesman. I think he had been the governor or viceroy of India among other things, and in this house were the 17th, 18th, 19th century Curzon family portraits. I used to look at them. There was no soul, the pupils were all closed. My family had recently purchased a bottle opener that made very nice round circles and I went around opening the windows on all these paintings. No one noticed my handiwork for months and months until. The devil, dressed as a as a diplomat, came to visit and put out. Apparently I wasn't there. This was late in the evening. He put out his hand to shake my father's hand, but without stopping he kept raising his hand and he said there are holes in those paintings. Do you have a son just like that? He had found the culprit and my I - I had just received a set of lead soldiers. And painted hand painted lead soldiers. My father in in great great agony dumped them into the furnace and just about the time the paintings were restored, the furnace was replaced. So that was the beginning of my artwork. Then after that we came to the States where my father became the military attaché to Washington and -- I went to a school called Saint Andrews in Delaware. I don't know if anyone's heard of it, but it's where the Dead Poets Society was filmed. In fact, in the 1980s, I was on the board of trustees and Mr. Robin Williams and Peter Weir came to to plead with us to let them use the campus for this film. We were reticent because that year a child had committed suicide. But fortunately, they did use the campus. They made a wonderful film. But in those days, in the late 50s, when I was a student there, the father of a student came to give a talk. He was an engineer by training. He gave a talk on dynamic symmetry. About Fibonacci and the Golden Ratio. And for the first time I saw how mathematics and art could be used together. How they could, how mathematics could be used in composition. And over the years in fact, I just told a friend that we had a substitute art teacher one Saturday. The man came in, he introduced himself as Andy. And he sent us out to do some drawings of trees. Then when we came back, he put some magical touches on them. They came to life. He was a superb artist. We didn't realize then, but this was Andrew Wyeth. His son Jamie wrote a nice blurb for the back of my other book, Math and the Mona Lisa. So over the next 25 30 years, as I did my art, I would use these ideas, these mathematical symmetries and patterns. What I realized was this is what Leonardo had been doing 500 years earlier. I was the product of an education, and he had absolutely none. But he was, [?] and he did it better than anyone else, anyone else in history. So as I gave lectures, especially on cruises, my wife and I have been very lucky for two cruises in tandem. Each summer we go on the Crystal Serenity and I give talks on an academic salary, I could never do this. But if you're an embezzler, an intellectual embezzler like this, you can do it. And I kept getting pressure to publish some of these these notions how Leonardo used --mathematics. How he uses science, how we invented everything. These magical works he did. Finally, in 2000, I was teaching a graduate course called Character of Physical Law. This was a title that Feynman had used in one of his series of lectures. And in the -- I was teaching the class and I in a weak moment, I told the students not to take notes, that I would write out the notes for them. Well, these became the seeds of a book. Initially it was going to be called the two Leonardo's, and indeed there are two Leonardo's, and I'll tell you about them. Actually, one of them was Leonardo, obviously. The other one was Leonardo Fibonacci de Pisa, who lived 300 years earlier. Oxford University Press and the Smithsonian were both interested in publishing the book. I went with the Smithsonian Halfway through the book, they said this sounds like 95% Leonardo da Vinci and only 5% the other person. Can you think of another title? One with a possessive would be good. That's because Davis Sobel's book was out Galileo's Daughter. And she wanted to. They thought this would be a good, inspiring title. I said yes, I said Leonardo's model. That's a double entendre, just like the two Leonardo's. In science, we always use models to explain things, especially in physics. Mathematical models is the way we we explain nature. And then there was the woman who sat for the most famous painting in the world. They said great, we'll make it Leonardo's model. A good friend of mine, a Nobel Prize winner here in Maryland. In fact, Bill Phillips said that's perfect. That's perfect model is very important for physicists. When I was finally finished with the book, 13 chapters, they invited me back in and they said it's not going to sell with this model, with this name. We have to change the name, I said we've been using Leonardo's model for months. And the book keeps referring to Leonardo's model. I said, what would you change it to? They said, what do you think of Math and the Mona Lisa? I thought from it there was alliteration. There was also the license to put the most famous painting in the world on the cover. I said, I guess it would work, I said. The publisher, the editor, smiled from ear to ear, pulled out the cover. It had already been printed. They decide these things for us. And they seem to know much better than an author would know. The marketing department really does do much better. It's in 12 languages now. I can read them in two in English and Turkish. And the Turkish translation is much better than than the way I would have written it in Turkish. It made sense. A very long time ago, in fact, exactly 30 years ago, in 1978, I was attending a conference in San Francisco. Sir John Eccles, the brain physiologist, Nobel Prize winner from Australia, had invited me to the conference. There were 400 people. I think there were 18 or 20 Nobel Prize winners, but fourteen of them were attending one session. That was truly a slippery topic at best. Extraterrestrial Intelligence Within the Framework of Rigorous Science. Now, let me ask you how many of you in this room believe there is extraterrestrial intelligence? I'm not going to say Leonardo is extraterrestrial intelligence. OK, that's quite a few. How many of you believe there's terrestrial intelligence? We do live in Washington, so. There's very little evidence of well, this was the idea we were working with the Drake Seven Factor formula or the Marks 9 factor formula. We know that the Earth has been a successful laboratory. We live near a star called the G2 type. And at a certain distance from this G2 type of star, that'll live a total almost 10 billion years, there has been the the appearance and evolution of life. So that's these are some of the factors that go into the formula. The probability turns out to be about 10 to the minus six, one in a million. But we live in a Galaxy of 400 billion stars, that's 4 times 10 to the 11. When you multiply the two two numbers, that's 4 times 10 to the five there should be 400,000 intelligent civilizations right now. This doesn't mean we can communicate with them. The distances are too great, although there's a good chance radio signals are out there in the airways, just as our signals are constantly going out. For 50 years now, we've been broadcasting in the megawatt range. And Elvis Presley and Leave It to Beaver from the 50s are all out there. They're now past about 450 stars. They have to go much farther, a million stars, before they get to the right density, the right probability, or the next concentric circle. So this is the sort of argument we were making and. At one point I got up to a microphone to say something, something inconsequential. But right in front of me was Yuval Ne'eman, Israel's greatest physicist. And right behind me there were two Nobel Prize winners, Sir John Eccles and Wigner at Princeton, and he and I decided to pull out of the line. But Eccles was holding my jacket and he said Atalay, we want to hear a youthful opinion. And certainly 30 years ago I was more youthful and more opinionated. I couldn't sit down. Yuval Ne'eman said In my country, he said we have a story. A woman is pregnant for the fifth time. She goes to her doctor and she says I'm really worried about this. The doctor examines her and says you have nothing to fear. She says you don't understand this is #5. This goes back and forth until. She says you keep missing the point. According to statistics, every fifth child born is born Chinese. [ Laughter ] 21% of the world is Chinese, so this is quite right. He gave me the microphone and sat down. I had forgotten to what I got up to say in the 1st place. Fortunately, just a few weeks earlier, I was in the doctor's office in Oxford looking at The Lancet. And in the last that they had a story about the fifth child, a woman goes to her doctor and says she's pregnant for the fifth time. This is a true story and you have to vote on this. The woman says she's suffering from tuberculosis and her husband is suffering from from, I think, syphilis. So this is a real problem and and the doctor has to advise this young woman, especially since she's already had four children who are blind, stillborn, deaf and dumb and the 4th one has tuberculosis. True story. How many of you would say she should have the fifth child? No one here? 2 3 4 5 hands in the right side of the auditorium, okay. In that room with 80 people, there were, I think 65% of them said terminate the pregnancy. The baby that was born was Beethoven. But you see, this is an anecdote and you can't base this is not a valid statistical problem in this case. But maybe of course Beethoven became death later on. But he produced some of the greatest music, maybe the greatest music ever produced? You know, Ne'eman came up to me right afterwards, the Israeli, and he said try this one, he said. A woman that's pregnant for the first time. She's in her mid 40s. She's married to, she claims, a distant cousin who's in his mid 60s. It turns out she's married to her cousin, to her uncle. Would you like to vote on that? Who says have the baby? Just one -- two. Three okay, this baby was born. This was Adolf Hitler. [ Laughter and electronic beeping] Again, you've got to be careful because these are anecdotes. The final story is of a 15 year old girl impoverished gets pregnant. Her boyfriend has money, but marriage is out of the question for socioeconomic reasons. I won't ask you the the to to choose in this case. This is Leonardo da Vinci. The love child of a 15 year old girl, a 26 year old notary, Ser Piero da Vinci d'Antonio, probably in Vinci, but it could be in the village of Anchiano. [?Not quite, no.?] We know the exact time of his birth and the parents, but we don't know where he was born, his grandfather, the notary, wrote my son Piero, son was born Leonardo and the date was April the 15th, 1452. We know that the boy lived with his mother for the first five years. And the next 10 years he lived with his father, who came and took the child. When the woman he married turned out to be barren. In the words of the day, he had no schooling, he attend he when he was 15, the family moved to Florence, where he became The Apprentice of of Andrea del Verrocchio, prominent artist, goldsmith. Absolutely perfect fit. Like Leonardo -- Verrocchio had been an illegitimate child and he would teach the apprentices di Credi, Botticelli, Ghirlandaio. Ghirlandaio became the the teacher to Michelangelo. Incredible, stable in a sense of of artistic talent. He would teach them to learn from nature and not from each other and he would tell the students. He would tell the students to learn the body from the inside out. He had no idea to what levels Leonardo would go to learn the the body from the inside out. Sherwin Newland, who was his professor of surgery at Yale. And a very fine writer and Leonardo expert, especially on the medicine, calls him quite simply the finest anatomist in history. He was doing his own anatomical dissections and he was drawing them with this remarkable talent he had. He was always -- he was left-handed. He didn't have a poor first grade teacher who would tell. I think we can probably put down the other screen, Tony. Is he around? [ Motorized screen deploys ] Thank you. [ Motorized screen deploys ] [ Constant projector fan noise ] [ Lights out, overhead projector activated ] When a left-hander and a left-hander draws, he shades with his with a negative slope. This is a negative slope. I'm completely righthanded, so I have a hard time doing it. This is a negative slope. When I draw, I shade with the righthanded stroke or positive slope. That's the telltale clue. All Leonardo's drawings have have a negative slope. He also wrote backwards. He wrote with his left hand. He wrote Leonardo like this. [ Transparency illustration ] This is the way he would have written. It's just much easier to pull a pen than to push it. Especially if you're using a quill. It would get stuck in the paper. You see people who are left-handed now sometimes pulling a pen this way so it wouldn't get stuck in the paper. We have about 4000 pages of the original 20,000 pages that is estimated to have been produced by him. It's all left-handed except when he's applying for a job. Then he writes from left to right, presumably with his left hand. Just to help you remember, that's right here. [ Zipper opening a case] So you may know this already, but these are a pair of striped ties. Here's the negative slope, the left-handed slope. It's an American tie. All American striped ties have negative slope. Here's a European tie. English in this case. Now this is Italian has a positive slope. All European and Asian ties have positive slope, so Leonardo's I had shading would have been this way, and it also shows that he was probably American after all. [ Laughter ] I'm wearing a sort of loud tie, but it's designed by Leonardo. You see the drawings now, the other Leonardo. Let me tell you about the other Leonardo -- then Leonardo Fibonacci de Pisa of Fibonacci de Pisa was educated at the University of Fes, the oldest university in the world, dating back to the 9th century AD. He was there because his father a minor customs official from Pisa. Was living there and he learned mathematics and and astronomy from the Arab scholars. Certainly far ahead of medieval European scholars. Whenever you see a word with A L in front, like algebra, it's an Arabic word. A L all means -- the -- algebra. -- Alcohol. Alchemy. These are all Arabic words and Arabic inventions. Alimony is not. Alimony I understand comes from Southern California. [ Laughter ] Well, Leonardo Fibonacci de Pisa came back to Europe to Pisa and in 12O2, while the Leaning Tower was just being erected, he was living in the shadow of the Leaning Tower. He wrote a book called The Liber Abaci. The Book of the Abacus. The Liber Abaci, sounds very much like the name of a late pianist. In The Liber Abaci he introduced, he starts out by posing this question. He says read this number. XCVIII. Anyone read this number [ XCVIII ]? -- 98 is right. How about this number? It's a little harder. [ LXLVIII ] L is 50. Maybe that's a clue. 50 -- 10 less than the next 50 -- 98 again. So it's not ambiguous. You can write the same number in different ways. 1999 you can write four or five different ways. He suggested following the Arabs making 98 like this with two symbols. There is no zero in the. In the European or the Roman system, following the Arabs, he introduced the zero. The zero had been invented back in the 6th century BC In India. Aryabhata, the great astronomer in 500 BC, had formalized the zero. In The Liber Abaci, Fibonacci proposed the following symbols, one vertical line for 1. 2 horizontal lines, tenuously connected for 2. 123 -- 1234 -- 12345 -- 123456. So the number of straight lines reveals the value of the symbol. The seven takes some imagination. The case of seven he proposed -- 1234567. The 8. 12345678. The nine he borrowed from the Arabs and the zero from the original Hindu literature. A circle. The Arabs actually make their numbers like this. Rotated 90 degrees you can see the Arabic numerals. This is 4. This is 5. 6 is like our 7. 8 - 789 and there's the zero in the real Arabic numerals. He did algebra in the book. There were 13 chapters. The 1st 12 chapters were all about the number system. Then finally in the last chapter he introduced a new problem. a problem of rabbits left to multiply in an enclosure. Now the rabbits are going to multiply according to the rules. In the first month in a room like this, there's one pair of rabbits. In the second month, they mature for one month. In the second month, when they're two months mature, they give rise to one new pair as an offspring. In the following month, the original pair reproduces again, but the second pair is 2, is immature or not mature, and they don't reproduce. But the following month they all reproduce. So here's the way it goes. In January, the first month is 1 pair of rabbits. In February we'll give them an year, one year. In March we'll give them a second year, and they reproduce. In April, the 4th month. Here's the original pair. Is 1 new pair. This pair comes down and gains an ear. In May the 5th month. Here is the original pair and one new pair. This pair gains an ear. This pair comes down, gains the second ear and reproduces. You see how it works? It's all in the ears. In June the 6th month. Here is the original pair. One new pair. This pair gains an ear -- this -- Oh -- This one gains a ear. This one gains a second ear. Wait a minute. This one came down and reproduced. This one gained an ear. This one gained a second ear and reproduced. This one was mature. They reproduced. This one gains an ear. Now the numbers are 112358 -- 8. Now his question became, is there a way to ascertain how many rabbits there will be at the end of the year? If he keeps drawing these ears, however, he's going to fill up the sheet very quickly. Did anyone tell me how many? 112358 --13 --21 -- 34 -- 55 you see a pattern yet? 89 -- 144 233 -- 377 -- 610. What's the algorithm? [ Indiscriminate audience feedback ] Add the last two to get the next term. 2584 like this. This is called the Fibonacci sequence or the Fibonacci series. This is what he discovered and published it as the 13th chapter of the Liber Abaci. What he didn't know was these were nature's numbers. Nature likes these numbers. If you take a pine cone, there are these scales that go up in a Helix clockwise, and then they go this way. You turn it over and look at the base. There are these spirals that go this way. Then as you look at this spirals, you will suddenly notice there are spirals that go in the other direction as well. [ Marker placed down ] [ Another color selected ] Like this. There will be thirteen in one direction, 8 in the other. It can't be anything else. A pair of Fibonacci numbers, always the same. This is the phyllotaxis of the pine cone. If you take a sunflower, [ Drawing ] you find that there are the seeds make spirals in one direction and then spirals in the other direction. The phyllotaxis of the sunflowers 89 to 55. There are some species that are 55 to 34, but always sequential pairs. Here's the 21. 34 -- 55 -- 89 pairs of Fibonacci numbers in sequence. If I draw or paint a tree, I start from the bottom up. Here's here's how it goes with a tree. I start at the bottom, and at one point the tree branches into two and then after a while one of these will branch, but this will not. After a while, one of these will branch. This will not, but then this will branch. Then at a different level, one of these two will branch, this will not. This will branch and one of these two will branch. Like this. I'm right-handed so I would have the shading this way I would make it if the light is coming from the right, this side of the tree is darker obviously. But what does it have to do with Fibonacci? You see any pattern there? [ Indiscriminate audience feedback ] 1 -- 2 -- 3 -- 12345 -- 12345678 and at any given height is a Fibonacci number. Now no self respecting artist really goes around counting branches. Leonardo did. Leonardo was compelled always to look for patterns. And his notebooks, he shows these patterns. That's what he was doing. Now. Of the four characters I mentioned earlier, the tales of the fifth child, the first one was apocryphal. Well, it was. It was the Chinese baby. But the others, Beethoven, is a transformative genius. Hitler is an evil genius. Leonardo is a transformative genius. There's a difference between the ordinary genius and the transformative genius. We all know some ordinary geniuses. I've known. I've worked with 20 Nobel Prize winners in physics. Most of them are amazingly intelligent. They've also come from supportive houses. This case of Dirac -- Dirac, who synthesized quantum mechanics, comes very close to being a real transformative genius. But the entire 20th century probably produced only one. Albert Einstein is probably the greatest genius of the 20th century, the man of the 20th century, according to Time magazine. Of the 20 Nobel Prize winners I know. We can. We can usually explain how an ordinary genius comes about. The parents are smart. There are lots of books in the house. This makes a big difference. Whether they read them all is in in material. They never do. But the books are there. Not just one huge Bible, but lots of books in the house. There's a correlation between the number of books in the house and the SA T's -- SAT results. George Will published some very interesting statistics on that once. It's probably the mentality in the house. That's what the large number of books suggest. But with these transformative genius, there's no explanation. You never know where they come from. In the case of another in music, probably Beethoven. Not too far behind Bach and Mozart at the Aspen Institute there was a very good science musicologist who was convinced it really was Beethoven and [?] who lived in the time of Beethoven. These are people who define entire fields or write new paradigms. In the sciences. The greatest scientist is Isaac Newton. Probably as far above Einstein as Einstein's above is above the rest of us in the field. In literature, no one will argue who the greatest writer is. You start ranking at #2. It could be Milton, Inc, or it could be Schiller, but or it could be one of the great Russian writers. But about #1, everyone will agree. They'll even say Shakespeare in Russian is the finest literature in Russian. So about transformative geniuses, everyone will agree, but we never know where they come from. In art, you start ranking at #3. It could be Raphael or it could be Rembrandt. Numbers one and two are sewed up. Leonardo and Michelangelo are the two greatest drivers of all of art. They're that far above. They're in the stratosphere by themselves, and then the others are distributed below. In the case of Michelangelo, Michelangelo lived to be 89, He was prolific, and he produced those incredible magical statue statuary. And under protest, he painted a ceiling. One of the greatest works of art in history under protest. Leonardo. How many paintings did he produce? Any idea? More than 3. [ Laughter ] 15. You're in the right ballpark. He probably touched 17 paintings. Six of them we know are 100% by him. The three portraits, Mona Lisa, the Cecilia Gallerani in Poland and the Ginevra de' Benci in Washington, the only Leonardo outside Europe. But here is the most important one of the two most important artists in all of history. What was he doing the rest of the time, is the question, and what he was doing was science. The rest of the time, I'd like to. With these numbers that I gave earlier me quickly give you one more thing and then we'll go to the slides. My wife isn't here to go like this to for me to go on to the slides, so 1 / 1 is 1. 2 / 1 is 2 -- 3/2 is 1.5 -- 5/3 is 1.666 8/ 5 is 1.60 -- 13/8 is 1.625 21 / 13 is 1.615 34 / 21 is 1.619 -- 55 / 34 is 1.617 1.618, and as you go farther and farther, by the time you get out to here, the ratio is 1.618034. This is the golden ratio. This is the symbol the the ratio designated by phi or fee. The golden ratio. We seem to have an affinity for the for the number. We see it in nature as subliminal messages. It's in all the plants. It's in crystals. We have an affinity. We like this number whether we can put our finger on the reason or not. We like this ratio. For example, 3 by 5 index cards is a golden ratio. It comes out of The Liber Abaci and the amazing thing is amazing thing is that 1800 years earlier, the Pythagoreans could create that number with a with a very simple construction. They would take a square. They would bisect the square. They would take a compass and put the pin of the compass here and the pen over here. So this becomes the the radius of a semicircle like this. It's more like it. Now they extend, let me do this again. Here is the square. It's been bisected. This diagonal is used as a semicircular arch arc. This is extended. You drop a vertical line and you complete the rectangle like that. This is 1 unit by one, or -- .5 -- .5 -- 1. Now using the Pythagorean theorem you find that it's the square of. 1 + .5 square, which happens to be 1.118034. That's what this distance is. Therefore that's what this distance is. You add to this the .5 over here, You get, 1.618034. That's the golden ratio, approximately the three by five card. Or or here, a credit card. It's meant to appeal to us. You see, it appears more to my wife than it does to me. But but it's a golden, it's a golden ratio. I'll just leave it. That's OK. Thank you very much. The Pythagoreans invented this in the 6th century BC. Then in the 4th century, 5th century BC, what's generally accepted as the most beautiful extrovert building ever built. Extrovert because they couldn't span large distances, they had to have too many columns inside. They built it in one of these rectangles. Like this. Or 8 columns, 3 steps at the bottom. There are the columns. they're fluted. The fluting gives it a lighter-- lightness. They're a little bit fatter on the sides than they are at the top. They sort of flare, a little bit. And then Pheidias, who designed it. Pheidias was the greatest sculptor of antiquity. He and his two assistants, Callicrates and Ictinus, built this building and then Pheidias came back. That's who gives us the pi for that symbol, he inscribed the-- What's the building? [ Indiscriminate audience feedback ] Parthenon. The Parthenon, right, Pheidias came back and embellished it with the most beautiful carvings ever, ever done until the time he carved them for the British Museum. Have any of you here seen them? The Elgin Marbles? Yes. But but Pheidias was so clever, he realized that a perfectly straight line will look like it's sagging because the horizon itself is convex like it this. So held against the convex curvature, a straight line will look like it's sagging. So Phineas made sure that this was convex with a radius of curvature of 3 1/2 miles, and he made the columns meet in the air. At a mile and a half, you look at the Parthenon. Now it looks perfect. It looks like all the lines are straight. But when you take photographs from a distance and measure them, you realize what he was doing was putting optical illusions in to to neutralize the disparaging optical illusions, what nature plays on us, in a sense. So the greatest extrovert building ever built. In a golden rectangle. The Romans used the Greek principle, and then it was forgotten in the medieval days and the Renaissance, it was reintroduced. You're an artist in the Renaissance and you're going to do a portrait first. You start with a rectangle, maybe 100 centimeters by 162 centimeters. That will give you the 1.62 or 1618. You draw the diagonals in of the square and of the rectangle, and you plant the head right here, that's the golden spot. Just like on a tennis racket, there's a golden spot. That's where you put the head of the of the subject. Are there any artists in the room? Willing to admit, I see two hands. They're only like this. Well, it's supposed to be 5% of the population. One out of 20 people apparently have artistic ability according to Betty Edwards' wonderful book Drawing on the Right Side of the Brain. Until we're ten, we all improve our drafting ability and then some metamorphosis occurs and we start to to regress. Only one out of nineteen 5% keeps getting better. They look at what they're drawing. The other is go by their memories more rather than what they're looking at. For example, on the face, the eyes go on the equator. You divide the equator into five. The eyes go here and here, like this. The width of the mouth is the distance between. If the pupils like this, if you're a Leonardo, you might even know that the forehead divide the distance from the hairline to the eyes compared to the length of the nose is 1 to one 1.618 to 1. But only if that's a perfect face. And if it's a really perfect face, then the length of the nose compared to the distance between the nose and the mouth is 1.61821. It's called the Marquardt mask, fashioned in California by aesthetic surgeons based on Leonardo's numbers. And that's what they use to improve the face. One last thing. I'll go to the slides right away. Here's an XY axis. If you draw this, measure this distance and you contract it to 62%, Here's 50%, here's 62% and mark it over here. Now you take this, contract it to 62%, contract this to 62%, and keep going clockwise. You connect the locus of points like this. This is a spiral called the logarithmic spiral. The spiral nature likes. There are other spirals. For example, this is a spiral. This is a garden hose, our comedian spiral. This is the logarithmic spiral. Nature likes the spiral. There are even creatures that that. Make their homes in these spirals like they go like this. I drove on. Yeah, that's right. The the chambered nautilus is a logarithmic spiral. So is a hurricane. When you watch hurricanes develop on television, sometimes shot by by NASA satellites, they look like. In the northern hemisphere, there are clockwise counter clockwise spirals. In the southern hemisphere there'll be just the opposite. There's there clockwise spirals. Because of the way the Earth rotates. And their spirals when you go to, I think we can go to the other screen. Now there's also the spiral galaxy-- galaxies are spiral galaxies-- logarithmic spirals. Nature does not like the other spirals. [ Motorized screen retracks] We can probably turn down the lights some more too, Tony. Oh that's Math and the Mona Lisa the last book, the one that wound up in in so many languages and in that picture. In the back. I don't know if you can make it out the so-called grotesques. This was designed by the Smithsonian, but right there for me most important drawing of all. About eight years seven years ago, we had an exhibition at Mary Washington where we collected some of Leonardo's inventions and from the National Gallery. But we bought some facsimiles of the drawings. My colleagues wondered why I would select this one. This turns out to be the design for the reflecting telescope, 168 years before Isaac Newton invented the reflecting telescope. Oh, these are some of the covers. The international covers of the book is one that doesn't quite belong in there. That's from Mad Magazine. [chuckles] Alfred E Newman. That's an early laptop. How many of you here use Macs? Macintosh computers? Not too many. Anyway, when I start getting royalties for Mac and the Mona Lisa, I bought a nice 17 inch G4 Mac G4 and I received a letter from a friend. An Italian friend who said Umberto Eco wrote an essay about Macs versus PC's. It seems the Macs are the Catholics of the computer world, and the PCs are the Protestants they can interpret any way they want, so that's a later model. There's the Parthenon, as it would have appeared if the lines were straight. Of course here it's been exaggerated, but it would have looked like it's-- concave. The size of the columns would look like they were concave. Instead this has been exaggerated in the other direction, where there's a convex curvature. It's a picture I took at the Parthenon a long time ago 25 30 years ago. I was there with a dean from the University of Virginia, and at one point I saw him tying his shoes, but then when he stood up he was ashen white. And I said, oh my god, I said, are you sick? And he said, no he had just thrown a piece of the Parthenon, he said, and he could wind up in prison. Well, we sort of covered from as we walked off the Acropolis. Just then a truck appeared and dumped tons of stones for the next day. So they were ready for for this late dean. This is Wilhelm Renken's image. One of the first two or three images he had, he produced. Wilhelm Renken won the first Nobel Prize in Physics in 1901. But here are bones of the hand, the carpals and meta carpals. If you divide A/B by BC, it'll be 1.618. If you divide BC by CD, it's 1.618 all the way down. It's also true of the hand and the forearm and the entire arm, that golden ratio. It's also true for the width of teeth. That's what aesthetic dentists use when they make the incisors 1 unit wide, and then the next pair will be .618 of the width of the incisors. In the 19th century, Fechner took our rectangles in different proportions and canvassed a lot of people, and he found that there was a great preference for the ratio 1.62 -- 35% of the population, like this ratio over all the others. I use my Macintosh and graph theory to draw the five. Polyhedra. These are. These were discovered by the Pythagoreans. This is the the tetrahedron. The octahedron. The cube. This is the dodecahedron. These are truncated or stellated figures that my computer could design. Leonardo, 500 years ago he illustrated a book for his friend Luca Pacioli. Where he invented transparent polyhedra so you could see right through them and see the edges On the other side. There's the book, and this is Leonardo in his deathbed. The painting is from the 90 from the 20th century, but Leonardo attended to by King Francis, the first in the time of Florence. There had been a rivalry between Brunelleschi and Alberti to design the doors of the octagonal building, the Baptistry. Fortunately, Ghiberti-- Lorenzo Ghiberti won the competition and he spent almost his entire life building carving these doors. These gilded doors, which later Michelangelo deemed I called the The gates of Paradise. And they've stuck. For 400 years we've known them as the Gates of Paradise. And anyway, this allowed the loser Brunelleschi, to go to Rome. And when he came back, he had developed perspective, linear perspective for artists. So one of the most important discoveries in all of art, depicting buildings as they should look rather than as we think they should look. Perspective. He also built the Dome, the famous dome of the cathedral in Florence. On the orphizi there is Leonardo and one of the they have in the niches on the sides of the Orphizzi, Orphizzi, some of the great sons of Florence, including Machiavelli, Michelangelo, Donatello. But this is Leonardo. David versus Goliath. Florence always saw itself as David, always being invaded by larger powers, Milan and Pisa, and each time it came out and survived, it would commission a new David. This is the David of Donatello, 1430s. This is the David of Verrocchio, Leonardo's boss. The competition was laid to rest by Michelangelo's David another 40 years later. Nobody ever did David's after that. It was this one was too good. But the second one is to me, the most important. It was done around 1471. This is I took this photograph last summer. It's very high. There's a a pedestal about this high and then the statues stands another five feet. I had special permission. I put my camera on top and I extended the tripod full distance and took the picture from the side. I look at this David, look at Leonardo in his old age. He was the model for that young David. You can see the nose, the eyelids, the cheekbones. It's David, the transformative genius as a teenager. When Verrocchio got a commission to to paint the The Baptism of Christ. Well, he designed it and he painted most of it, the rather stiff, wooden looking figures. But then he asked his assistance Botticelli, and Leonardo to paint the angels. This is Botticelli's angel looking at Leonardo's angel. When Verrocchio saw Leonardo's work, he gave up painting. Never to take another paintbrush in his hand. This is the genius recognizing the transformative genius. Just like Isaac Newton. His, the bubonic plague was sweeping through England and Oxford and Cambridge were closed down. Isaac Newton, with all his colleagues, went home when they reappeared at Oxford at Cambridge rather 16 months later. Isaac Newton had a list of his mental inventions. He says he applied the binomial theorem to to determine the slopes of curves. Then he says, now I know fluxions. Then a few weeks later he says, now I've invented inverse fluxions, differential calculus and integral calculus. Then he discovers his three laws of motion. Everybody knows the third law. Goes for every action. What's the rest? There's an equal and opposite reaction. For every force, there's an equal and opposite force. I pressed down on the floor with my weight. The floor presses up with me with an equal force in the opposite direction. Anyway, he discovered these. Then he discovered the universal law of gravitation. What keeps the moon in its orbit? This is really the beginning of mathematical science, and it's also he wouldn't publish it for 20 years, but when he finally published it, it completely revolutionized science. On the list of 100, the 100 Most Influential People in History, he's #2, because the Industrial Revolution, as a result of the scientific revolution, starts off with Isaac Newton. He's that significant. But you see, when he came back and showed a list of his inventions, mental inventions, to his professor, a great mathematician, Isaac Barrow, Barrow immediately retired and became a priest-- [Laughter] --again, a transformative genius being recognized by a by an ordinary genius. At 19, Leonardo put that sphere, it's a 2 meter or 8 foot diameter sphere on top of Brunelleschi's wondrous dome. But this is where his mechanical abilities skills started. When he was about 27, he applied for a job as a engineer, military engineer in Milan. In this castle he worked for the Sforza. He was a bundle of contradictions. He was a pacifist who worked as an engineer, as a military engineer. These are some of his drawings of they're called the grotesques and the proportions of the face, the golden rectangle, the proportions of the face you can see in this drawing. He is designing the side-wheeler. The left-handed shading. You see the negative slope here-- and there's a replica and exploded diagrams of gears. This is 500 years ago, They wouldn't appear again until the 19th century. Here's the automatic transmission and this page. These are robotics. Well, this is just an odometer. It's a very simple wheelbarrow. Every time the wheel turns 30 times, it causes this wheel to turn once. Every time, this turns once 30 times. This one turns once, so 30 square. This has to turn 900 times for this to advance by one and a little ball falls into this box. Here you just take them out and count the number of balls. It's a simple design. But these are not. These are robotics, and this is the robotic knight. What he seemed to have that we don't have is preternatural vision. He could freeze motion in the air. The last person I've heard of who could do this was Ted Williams, the baseball hitter. He used to insist that he could see the seams and writings on a baseball. That's what you need to to actually-- preternatural vision. Leonardo illustrated rings of notes and notebooks with the serial motion of wings flapping. He knew exactly how the wings of a of a bird had to go in order to elevate for the bird to ascend? He made these ornithopter wings, strap-on wings and clearly there wasn't enough energy in a manpowered ornithopter wings. You can imagine his assistants coming to work and being told they were going to test fly. Then he invented the aerial screw, which in the 20th century inspired Sikorsky to make the helicopter. And in case that failed, the parachute could come down with with the flyer. This was tested in 2000 in South Africa. It works. Unfortunately the frame a wooden frame around. It would crush the person coming down with it. But it shows that it would work. The evolution of the bicycle in the 19th century. 1818 a man would take a pair of wheels for a walk. Then the unicycle was invented, was balanced in the back, front and back, with small wheels in the rear, with a small wheel in the front. Finally, by 1895 the modern bicycle came to fruition. So 100 years in the industrial revolution, there is a $3000 Mercedes-Benz bicycle. These are designs for chains. And gears with sprockets and a bicycle 500 years ago. It's a little scary when you see things like this in the notes. There's the great Tower of Pisa. I saved some money on the footings, but don't worry, no one will ever notice. And here's what it looks like. And here are two people who know this Leonardo and Galileo. Galileo found that objects dropped from the side descended in the first, second one unit of distance, and then three, and then five, and then seven, and then nine. It's called the the odd number law. Leonardo measured with cruder instruments 100 and 120 years earlier. These were 123456 -- Again, sequential integers. When you take a sum of these numbers, they're both quadratic square of the time. This means constant acceleration, completely different than what Aristotle had taught and wrote about and that was still being used in schools. Here's the Aristotelian law that gives you the trajectories of cannonballs. Here is Galileo's discovery of the same time there were parabolas. Here's Leonardo's discovery 100 years earlier. They're parabolas and then the hands of Isaac Newton. These became ellipses, and it shows how you can attain an orbit 5 miles per second. You hit any hill at 5 miles per second and you'll go into orbit. Here's Galileo's telescope 1609. Isaac Newton's telescope reflector 1668. Here's the Hubble. And here's the Leonardo telescope reflector 1500. His drawings of of vital organs from the back and even from the front. It's impossible to make out the details, but this is all written from right to left. Explaining what he's looking at and building the body from the inside out. He visits the hospital, Santa Maria this and meets a very old man and he asked him, he says, How old are you? The man says. I don't know, but I'm very old, Leonardo says. What is very old? The man says. I don't know, but my grandson is 58. Leonardo figures the man must be over 100, and with a smile, the man suddenly passes away. Leonardo, known as the most relentlessly curious man in history, says I immediately did an anatomy of him. He does a postmortem. Few weeks later he does a postmortem on a child. And he says, in the case of the young child, the blood vessels leading to the heart were supple and clear. In the case of the old man, they were occluded and they were brittle. He's describing atherosclerosis 500 years ago. In the 20th century, Russian physician Nikolay -- Who is it? [Nikolayevich] Anichkov discovered that. It was it was essentially hardening of the arteries with cholesterol settling. And his drawings of the heart, and this is a heart that my son gave me. It's a it's a film so I could rotate it and get almost the same configuration. It's a cat scan image capture. At Cambridge University there's a well known surgeon, Doctor Francis Keele I believe, who does mitral valve repair using Leonardo's methodology. This is how he would have written. It's a little hard to understand, I think, hard to read. It's called the Da Vinci font. Now I can flip it over. Nature, being in in constant and taking pleasure in creating and continually producing new forms because she knows that her terrestrial materials are thereby augmented, is more ready and more swift in her creating then is time in his destruction. He's talking about evolution. That's pretty good 350 years before Darwin. In the euro, one side is always the one, no matter where you go in Europe. But in the Italian euro, it's the Vitruvian man of Leonardo. In Austria, it's the Mozart bust. The rush on. In 1480, people in Turkey say Leonardo was invent, invited to do a portrait of Man at the Conqueror. Leonardo couldn't stay. He couldn't go. He had just accepted a job in Milan, so Bellini went to do this portrait. But in 1503, twenty years later, Leonardo was out of a job, and he wrote to the Sultan in Turkey asking for a military engineering job, just like in his original letter 20 years earlier to the Duke in Milan. He he says, I can build walls that no cannon can pierce. I can build cannons that can breach any wall, and the last three words are I also draw. I also paint, but in the middle somewhere around here, he says. I'd like to come and build a bridge for you, a single span bridge over the Golden Horn. Not the Bosphorus, but the Golden Horn. Unfortunately, he wasn't hired. This was the bridge that was built over the Golden Horn. It probably lasted 5 or 10 years. This is his design. There is the bridge seen from the side. There it is, and it was finally built 500 years later in Stockholm. On the road over the road between Stockholm and Oslo. I invented the the pyramid composition. This is a drawing based on his The Battle of Anghiari -- was discovered in 1998. In all great portraits over the centuries, a line down the center always divides the goes through one eye. Christopher Tyler in San Francisco, an Englishman made the discovery. He was treating patients whose right and left hemispheres had been surgically separated. I think it's used for epileptic patients. Well, he had these patients, 20 of them, and he took his art books. He said he's a great art lover. He drew a line right down the middle so that the patients could look at one side and the other side. With his two sides separated, he said what astonished him was in all these paintings, the line went right down the middle, right down one eye. It doesn't matter which eye, whether it's the trailing eye or the leading eye. Here in the Mona Lisa, the self-portrait at the National Gallery by Rembrandt. Here's Picasso. Now, Picasso knew this. It's never taught in art schools. It's something the great artists simply focuses on. If Picasso had known the principal, he would have put the eye down here somewhere, but he fell victim to it. He didn't know it. Here is the old rabbi by Rembrandt, and there's more life than the Russian tourist sitting in front of it. It's in the Hermitage, right down the eye, right center. That's my son. He got his degrees at Hopkins right down the eye. Go home and look at pictures you've taken of people. It has to be a single subject. And see if you haven't focused on an eye. It has to be right down the middle of the picture. Except in this Jamie Wyeth painting, Kennedy's sitting off on the side. You see he's off, sequestered in his own world, solving problems. Jamie Wyeth painted this, Andrew Wyeth's son. When I saw that, I was shocked because the ratio is 1 to .618. I wanted to use this in my last book, Math and the Mona Lisa. And I got in touch with Jamie Wyeth and he wrote a blurb for the back of the book and later he wrote to me separately. He said he loved chapter 8. That's the chapter he appears in. Now the other principal that was discovered the same year it appeared made the front page of the New York Times. There's a preponderance of left cheeks over right cheeks in portraits. The question has always been who is deciding for the subject? Is it the painter or is it the is it the subject? Mike Nichols in Melbourne decided to put this to the test. Took a large group of 400 students. And he said, we're going to produce a portrait of you. And he took 200 of the people out, half of them. And he said this painting is going to hang in your boyfriends or girlfriends or your mother's house. And immediately it would be the left cheek 78% of the time. And men and women behaved exactly the same left cheek. Then he brought the other 200 in and let the 1st 200 go. And he asked them the same thing. But this time he said your portrait is going to hang next to Einstein. Now Einstein is a certifiable genius. So why do we behave? Everybody turn their right cheeks. See, according to the psychologists at the University of Melbourne, we emote on the right side and that controls the left cheek. So if we want to be endearing, we put out our left cheek. Doesn't matter whether it's our better side. If we want to be endearing, this is the cheek we present. We do mathematics right here in the inferior prior to lobe, just above the ear. Einstein had a special amount of that -- that controls the right cheek. So if we want to look smart, or if we want to be, to deserve hanging next to Einstein, we show this side. See it's a simple and elegant to next an explanation as any I've seen. I was giving a talk to high school kids at Thomas Jefferson, this very bright #1 school I understand in the country. And this one little girl asked whether when she goes to an interview, she should show her left or her right and she decides she would just oscillate slowly from one to the other. [Laughter] Okay. Now, in the three portraits, this one is in the National Gallery. It's just the square. First of all, the Golden Rectangle organizes the fleshy part of the painting. The height of the head determines the square, which is extended 62% in each case. The center line passes through one eye. They were painted exactly 15 years apart. (whispers) You have to go. See you later. Great. Thanks. Then in 1992, we wanted to borrow this for the National Gallery because it was it was the 500th anniversary of the discovery of America Columbus, and the painting had been created in 1492. So we, the National Gallery, appealed to Krakow to the Czartoryski Gallery -- where this billion dollar painting is, whether we could borrow their painting. The poles immediately replied. The lady was too fragile to travel. She couldn't come. The conservators from the National Gallery went to Krakow and examined her and found that it was in great shape. But more than that, they knew a secret about this painting. Leonardo's fingerprints. Were also in the neck of the chichilia. Leonardo had been putting paint on the paintings on the boards and using his fingerprints. He was finger painting and his fingerprints are in the in the painting. Right here is Leonardo's fingerprint. The National Gallery didn't have equipment cameras that could take these fingerprints, so the FBI came in and took these pictures. So Leonardo is now on file at the FBI and the painting came to the United States. We're down to the last few pictures, and I'm really sorry I've gone so long, first of all. In the mouth, there's an optical illusion. If you look right at the mouth, the smile disappears. If you look slightly away from the mouth, the smile comes back. If you look just with the fovea of the if you with the fovea of the eye, you look right at it. But there is no smile. It's an optical illusion. You need a more global view to see that smile come back. So one trick is to look away and come back. Look away and come back. Well, here's what he's done. The horizon line in the back is not level. It's slightly like this. This causes an unsettling effect and you go back and forth without thinking of it. It's inadvertent and you see the smile coming back each time. Do we do it on purpose? Chan I I was on PBS or NPR on Science Friday, and I was in DC. There was a Ira Flatow, who runs Science Friday was in New York, and Margaret Livingston at Harvard was in Cambridge, Boston, MA. We sounded like we were together in the same studio, but it was Margaret Livingston who had recognized this optical illusion. She didn't know whether it was done on purpose because it's the last painting he Leonardo did. But my experience is nothing is an accident with Leonardo. Oh, in the painting, the rocks that were always thought to be imagination, figments of his imagination. And the bridge right there, just next to her left shoulder, there are the rocks. The balls are rocks. And there's the bridge. Ponteboliano in Arezzo, which is close to Tuscany. The stealing of the Mona Lisa. In 1911, a Florentine national tried to steal them. Well, he stole the Mona Lisa. He had been put up to it by this embezzler who wanted to have copies made to sell to private owners. See. And once the painting was stolen, he hired a very good artist to keep producing copies of the Leonardo that he could sell to private collectors. Meanwhile, the person who stole it wasn't getting getting any money, so he tried to sell the original himself, and he was finally nabbed. But the the Mona Lisa was out of circulation for two years. That's my granddaughter looking at [Salvador] Dalí's Last Supper. There's the dodecahedron that that organizes the figure, and this is Leonardo's Last Supper, who's read The Da Vinci Code? Anyone here? Do you believe that this is a woman, or is it Saint John who says it's a woman? One-- she certainly does look feminine dosen't she? Well, Saint John was always depicted as a rather feminine character, even with paintings earlier, it is Saint John. It's not a that's an interesting little aside, but far more interesting. Leonardo was like a casting director. He knew exactly the images he wanted for his his characters, the 12 apostles in Christ. He would see them in the marketplace. He'd rush back and paint them. He had a hard time finding Christ a model for Christ, and a hard, even harder time finding a model for Judas. Finally he found his Christ and he painted him in. And a couple of years later a friend came and said, I found your Judas. He's in a prison in Milan. Leonardo went dutifully to the prison and agreed that this was a perfect Judas. And as he painted, do you see which one Judas is? Anyone see someone different from one reason or another? The only face that's in the shadow is Judas, right there. He's spilled his saltcellar and he's got a tiny little pouch in his hand. That's Judas. Anyway, as as Leonardo started painting the man, the man said, you don't recognize me, do you? Suddenly Leonardo recognized him and started trembling. It had been his Christ three years earlier. Certainly Dan Brown would have put that into his book if he had known. These are the names of the disciples. And leaving Hopkins one day I saw this huge billboard. This was discovered recently. They think that it's a Leonardo drawing 10 years ago when it was sold. Before it was, it was attributed to Leonardo is sold for £20,000, about $32,000 this year. Just recently when the attribution came out as a Leonardo, the price went up to £50 million. And we are finished. Thank you very much. I've taken-- [Applause] [Elizabeth Fee:] It's a little late, so I think we may skip the questions and answers for today. Those of you who have a burning question might want to come up and speak to --Card. The card. But please join me in thanking him for a very fascinating and enjoyable talk. [Dr. Bulent Atalay:] Thank you very much.