Texas. Thank you jim. Id like to start by explaining how i came to write this and why i came to write this. And to that purpose ill read from, initial part of the preface. Im a physicist not a historian but over the years ive become increasingly fascinated by the history of science. My own handwriting is touch on history, its been mostly the modern history of physics and astronomy, roughly from the late 19th century to the present. Although in this era we learned many new things. The goals and since the physical size have not materially changed. The physicist of 1900 were somehow taught todays standard model of cosmology or of elementary particle physicist, they wouldve found much to amaze them at the idea of seeking mathematically formulated and experimentally validated impersonal principles that explain the wide variety of phenomena would have seen quite familiar. A while ago i decided i needed to dig deeper to learn more about an earlier era in the history of science and the goals and standards of science have not yet taken their prices shape. As is natural for an academic when want to learn about something i volunteered the key to teach a course on the subject. Over the past decade of the university of texas i have from time to time the undergraduate taught undergraduate courses in the history of physics and astronomy the students had no special background in science, mathematics or history. This book grew out of the notes of those courses. What i found from my experience in teaching and from the reagan i had to do somewhat surprised me. People who recall the scientist in the past not only did know what we know about the world they didnt have the foggiest idea of what the worst in about the world or about how to learn it. You shouldnt imagine that the idea that i described of searching for and personal mathematically expressed laws of nature which can be used to explain a great deal and are validated by the success of those explanations nothing like that was imagined in the past. Science as we know it was not obvious to be put never seen it done. This is illustrated by a controversy that continued for over 1500 years, from roman times to the scientific revolution of the 1500s 1600s in both europe and in the lands of israel. This is when one of the stories i tell in the book. This one was about the planets. In many ancient civilizations people have noticed that there are five things in the sky that look like stars and like the stars and the sun and the moon seemed to go around the earth once a day once every 24 hours from east to west but over longer times these five wanderers moved in addition from west to east against the background of the stars through the constellations of the zodiac. And the greek called these wandering stars or planets and the romans gave him the name of gods mercury, venus, mars, jupiter, saturn. Some people engage world like plato actually thought they were gods. When the ancients turned away from mythology and started to develop a naturalistic picture of what these planets were, two theories emerged which were the subject of debate as i said for 1500 years. This is not an argument between those who think the earth is at rest and those who think the sun is out rest. Everyone with a few interesting exceptions in the ancient world thought the earth was at rest and this guy can do things in the sky were going around the earth. The argument was about how they go. One theory adopted by aristotle was not the planets are bright spots on seizures that rotate with the earth at the center, but the spheres have come to access on the sphere in which the planet right is attached to outer spheres, and the axes of these outer spheres were attached to get further spheres. And so you have a complicated rotating mass of the spheres but all of them with the earth at the center. The other theory had the planets going on circles but not around the earth, around moving points in the sky. The circles were called epicycles which themselves went around the earth, or went around other moving points which went around the earth. So you would have epicycles on epicycles on epicycles. The followers argued that the theory fit the data well which it did pretty well, for reasons we now understand. In a sense it was a sense of copernicus history. Appointed based on the earth or point of view based on the sun. The followers of aristotle said the theory of epicycles was nonsense. Things in the heavens can then move on the epicycles orbits. After going through goes with the earth at the center. And they knew that their theory didnt agree very well with observation and they felt, well something that really concerns mathematicians. Its not something that we have to worry about we, who are considered the true nature of things. Throughout the islamic period ended in early modern europe, the followers of aristotle often called natural scientists intended to be people like physicians are people we would today call philosophers whereas the astronomers and mathematicians tend to be comic. In the end, of course, the controversy was swept away by the adoption of the third of copernicus, that at the planets, including the earth and the moon, well no the planets and the earth go around the sun. Only the moon goes around the earth. It became understood that if there he worked as well as it did because it reproduced most of the features of the copernicus theory. Copernicus did not develop his theory because he was more attentive to observation and the followers. Let me know read a little bit from the book. Copernicus could not claim that his scheme to observation better than that. But one thing it didnt. Indeed it could. Since for the most part because based is very on data from a weapon from his own observations. Instead of appealing in observation, copernicus pointed out a number of his theories aesthetic advantages. One advantage is that the motion of the earth account for a wide variety of apparent motion of the sun stars and the other planets. In this way copernicus was able to eliminate one of the distasteful features of the other which a modern physicists would call fine tuning. For example its a common obsession we never see dean is far from the center its the morning star of the evening star, its never high in the sky at midnight. In order to account for the the followers of ptolemaic had to assume that the center of the epicycles of venus always stayed on the line between the earth and the sun, going around the earth in precisely precise when you india to make several assumptions about the other planets. We call this fine tuning, yet imposing a quality a quality of the time it takes to set of epicycles is to go and the earth with the time it takes the sun to go around the earth. It imposes and equality on things of the world where theres no reason why they should be equal. A fine tuning in a theory of nature is like a cry of distress. Its something tell you this is not right. And we continually face this sort of thing in physics. Physics. I tell a story in here about one of the great advances in physics about 50 years ago was made because some physicists were dissatisfied with the finetuning of series at that time. Right now we face a similar situation. Theres a problem associate with what is called dark energy. Dark energy is an energy and space itself. Not in any kind of particle the we know about or because it causes the extension of the universe to accelerate, speeding up, contrary to what you may think is gravity pulling everything back together again. Its like a repulsive repetition of force to it only becomes effective in very large businesses. Now, naturally physicists have tried to calculate the amount of dark energy the number of calories per cubic meter of space, say your. We can calculate some and not others. The contributions that we can calculate turnout to be much too large, too large as compared to the amount of work energy measured by astronomers observations of the universe is expanding. The terms in the dark energy we can calculate are too large body very large number. Won with 56 zeros following it. Quite a discrepancy. Its not a paradox because there are other contributions we cant calculate and they depend on constants of nature we dont know. We can adjust of those constants to make a cancellation. The 56decibel places. That is the kind of finetuning that tells us that we dont understand whats going on. Copernicus was largely led to his theory by the desire to eliminate the finetuning in the geocentric theories of the planets. Well, i felt a number of these stories, not just about planets but about other things i tell like the nature of matter, about the nature of light. And in all of them you see not just that the ancients didnt know what the matter was or what light was, but they did not even ask the question. For example at the very beginning of greek science decreed that all matter is water. And why then does matter not like a state of water . They didnt consider that question. And why should we think matter is made of water . Never offered a reason. Until the time of aristotle in fact the greeks who can when i was an undergraduate i heard called physicists never really considered why we should believe their theories and offered no argument. With aristotle, thinking about the world again more serious and more argumentative, ngc perhaps the beginning of science but aristotle had no use for mathematics and he was committed to a kind of things are what they are for the purpose, which weve learned to discard. But im not just telling stories about events in the history of science and about discoveries. I also tried try to bring some of the personalities alive. These after all were real people. We dont know much about the greeks, but when you get them early modern times, we have a lot of information and can build a pretty good picture. For example, this is what i visited about newton, the greatest physicist, not only of his age but probably of all ages. With the newton we come to the climax of a scientific revolution. But what an odd bird to be cast in such a historic role. Newton never traveled outside a narrow strip of england linking london, cambridge and its birthplace in lincolnshire. Not even to see the sea, is tied so much interested in. He never saw the sea. Until middle age he was never close to the woman, not even to his mother. In fact, vote there in his philosophical letters describes how he was in london when newton died and the doctor and surgeon confirmed through voltaire and it never had intimate relations with a woman although voltaire doesnt say how they knew. [laughter] nude nasty potential with mayors have little to do with science such as the phrenology of the book of daniel. A catalog of newtons menu script put on sale at sothebys in 1936 showed 650,000 words on alchemy and 1. 3 Million Words on religion. With those who might be competitors newton could be dojs and nasty and theres some stories in your doctor really quite shocking about the way didnt behave to people who are competitors. Yet he tied up strands of business, astronomy and mathematics whose relations have perplexed philosophers since plato. Writers about newton sometimes stressed that he was not a modern scientist. The best known stable along these lines was that of john made of teens who about some of the newton papers in the 1936 1936 option. He said newton was not the first of the age of reason. He was the last of the magicians, the last of the babylonians and samaria and, the last great mind which looked out on the visible and intellectual world with the same eyes as of those who began to build our intellectual inheritance rather than, rather less than 10,000 years ago. I dont quite buy that. Newton was not a talented holdover from a magical past. He also wasnt a modern scientist. Rather he crossed the frontier between the natural philosophy of the past and what became modern science. He provided newtons achievements was not just al gores personal behavior. Provided that there done that all subsequent science has followed as he became modern. In writing this the center of much interest is how we came to modern science. And so i find myself forced to consider what aspects of the thought of the past was progressive would help to develop what we now have as science come and what stood in the way. This kind of judgment was him is sometimes called we dish whiggish, coined by Herbert Butterfield in 1931. Judges the past by the standards of the present. He was considering political history. Butterfield opposed historians like mccauley who judged the figures that he wrote about in terms of what led to modern parliamentary democracy. Butterfield made a good case that transport is not appropriate in political history. It certainly wouldnt be appropriate in artistic history or you cant really argue that theres a definite sense of progress whiggary. But i cleaned it is the appropriate way of looking at the history of science where there is a definite sense of progress. It is cumulative. For example, heres what i had to say about aristotle. Well, first i quote in opposition to the kind of history that i intend that i intended to write, a wellknown historian of science [inaudible] gosh. Lindberg David Lindberg who died recently in january. Heres lindberg. It would be unfair and pointless to judge aristotles success by the degree to which he anticipated modern science, as though his goal was to answer our questions rather than his own. The proper measure of the philosophical system for a scientific theory is not the degree to which it anticipated modern thought but its degree of success in treating the philosophical and scientific problems of its own day. I say i dont buy it. What is important in science is not the solution of some popular scientific problems of ones own day, but understanding the world. In the course of this work one finds out what sort of explanation are possible and what sort of problems can lead to these explanations. The progress of science is largely a matter of discovery, what question should be asked. And i also make some comments on descartes. I call his theory of how to do science one of the most overrated contributions to the scientific revolution. And this is this has attracted a certain amount of attentions of the scientists of descartes but i drive the point home by commenting that although descartes had attempted to lay out what he called a method for rightly conducting the reason and determining scientific proof, thats his words, he got so many things wrong. And heres my little list welcome for some who claim to have found the true method for seeking reliable knowledge, it is remarkable how wrong descartes was about some aspects of nature. He was wrong in saying that the earth is the distance to the earth is greatest from pole to pole rather than through the equatorial plane. He, like aristotle was wrong in saying that a vacuum is impossible. He was wrong in saying that light is transmitted instantaneously. He was wrong in saying that space is filled with material that carries the planets around in their past. He was wrong in saying that the pineal gland is the seat of a cell responsible for human consciousness. He was wrong about what quantities can serve went particles collide. He was wrong in saying that the speed of a freely falling body is proportional to the distance. Finally, on the basis of observation for several lovable pet cats im convinced that descartes was also in saying that animals are machines without true consciousness. So much for descartes. [laughter] its interesting, by the way i butterfield who originated the idea of putting down the way historians wrote a book about development of science and in this book he sounds completely whiggish which i think is appropriate when talking of science because science come in science as we cannot in most fields, we can identify a clear line of progress. Heres a butterfield on the scientific revolution. He said it outshines everything since the rise of christian did it reduces the renaissance and reformation to the rank of mere episodes, their internal displacement within a system of medieval christmases. Now, its all been unplanned as i keep emphasizing. There was no idea if anything like modern science at the beginning, which raises the question, how did we get here . What theories of accidents lead us . I dont know the answer to that but i have an image of the world acting as a natural not particularly are fully built teaching machine reinforcing our successes just as in skinners way of educating pigeons, reinforcing our successes not with little else of pigeon food but with moments of great happiness, when we succeed in explaining something. This is the end of the main part of the book, and i will read this which offers this point of view. Having surveyed the fish of the physical size, i would like now to offer some tentative thoughts on what drove us to the modern conception of science represented by the achievements of newton and his successor. Nothing like modern science was conceived as a goal in the ancient world or the medieval world. Indeed even if our predecessors could have imagined site as it is today, they might not have liked it very much. Moderate sized is impersonal, without room for supernatural interventions or outside the Behavioral Sciences for human values. It has no sense of purpose and offers no hope for certainty. So how did we get here . Faced with a puzzling world, people in every culture have sought explanations. Even when it abandoned mythology, most attempts at explanations didnt they do anything satisfying. Thales tries to understand matter by guessing that it is off water but what could he do with this idea . What new information did they give him . No one in ancient greece could build anything on the notion that everything is water. As i said elsewhere the theories developed in those days had no bite. But every once in a while someone finds a way of explaining some phenomenon that fits so well and clarifies so much that it gives the finder intense satisfaction especially when the new understand is quantitative, and observation bears that out in detail. Imagine how ptolemy must have felt when he realized that by adding his own mathematical device called an equal to the epicycles of earlier astronomers astronomers, apollonius and hipparchus from he found a theory of planetary motions that allowed him to predict with their accuracy where any planet would be found in the sky at any time. We can get a sense of his joy from the lines of his eye quoted earlier, adequate and today so i will quote him now, when i search out this is ptolemy as quoted in the greek anthology which i search out a mass wheeling circles of the stars, my feet no longer touch the earth but sidebyside with zeus himself, i take my food of the gods. That joy was flawed. It always is. You didnt have to be a follower of aristotle to be repelled by the peculiar looping motion of planets moving and epicycles in ptolemys theory. There was also a nasty finetuning it had to take precisely one year for the center of the epicycles of mercury and venus to move around the earth, and likewise for the outer planet. For over 1000 years loss of us argued about the proper role of astronomers like ptolemy, really to understand the heavens are merely to fit the data. What pleasure to purpose must have felt when he is able to explain that the finetuning and looping orbits of the ptolemy schemascheme of us simply because we do the solar system from a moving earth. Still flawed the copernican ferreted not quite fit the data without ugly complications. How much of in the mathematically gifted kappler must have enjoyed replacing the copernican mess with motions on Alexis Gobain his three laws. So the world ask honest like a teaching machine, reinforcing our good ideas with moments of satisfaction. After centuries we learned what kind of understanding of possible and how to find them. We learn not to worry about purpose of such worries never laid the sort of delight we seek. We learned to abandon the search for certainty because the explanations that make us happy never are certain. We learn to do experiments not worry about the artificiality of our arrangements. We develop an aesthetic sense that gives us clues to what theories will work and that adds to our pleasure when occasionally they do work. Our understanding of generally. It is all unplanned and unpredictable, but at least we know that reliable knowledge and gives us joy a long the way. Thank you. [applause] so im happy to answer questions or what a privilege to ask a question that ive been curious for a long time. Lots of people. I hope i can make my question clear. I understand the universe started out very small and its been expanding for billions of light years. My question is what is the universe expand into . Im more interested in the space outside the universe. Just for a name, i dont know what you all call the. I will call it outer space or universe of space. Is anything scientists even think about our study are speculate about or is it of electors to scientists . There are some images that could be given and the Experimental Evidence seems to point to one answer. The best we have is that you shouldnt ask about outside because the universe as far as we know it is infinite. There isnt any outside. That matter that we see within a few billion lightyears of earth continues beyond that out to infinity. And its all expanding its not expanding from any center but the expansion does not mean like what would happen in this room if anyone started running away from a Central Point and maybe expand out into the parking lot. The expansion, you can imagine a universe filled with, not with people but with galaxies and they are all rushing away from each other. There is no center and there is no outside. The expansion of the universe just if it means every galaxies getting further away from every other. Thats all that means. It doesnt mean theyre some surface that is expanding. Thats the best answer we have nothing to our other possible answers. 20 or 30 years ago it was plausible that the universe was closed like a threedimensional surface of a four dimensional sphere. Thats harder to pitch and we dont believe in it anymore anyway. Forget it. Your examples have all been western. So were there no asian if there is that you considered, or are they in your book and you just didnt mention in . Well, i have a whole chapter on arabs science. The arabs picked up the torch which was pretty well going out at the end of the western roman empire. The greek half of the roman empire continued after the decline of the empire in the west for a thousand years and until the fall of constantinople in 1453. And no science was done none that i know of in the byzantine empire. But the arabs did pick up the torch, and not only translated greek works into arabic and learned greek science but improved on. And i have a whole, the great games in arabs science there are great names in the arab science, and this flowering of arab science itself petered out. Thats very controversial by the way. Many, especially muslim historians, try to emphasize the continuation of muslim science into early modern times. But, in fact, none of the great names are found after about 1100. And with the scientific resolution came it came in europe in italy poland, france and england, germany and not in the lands of islam. No islamic astronomer ever conceived of the, well they conceived of it but they never took seriously the possibility that the earth goes around the sun. Yes, i will come to that. I am not aware of any development in china or in india that builds the kind of impersonal nonmythological quantitative theories that you find in the hellenistic and arab periods, and eventually flower in europe into a scientific revolution. The west got a lot from china and other sources come in the especially and babylon. We got the existence of magnetism we learned from the chinese paper. Well, paper came from central asia better than from china. From india we learned a great deal of mathematics, including what we called the arabic Number System based on powers of 10. We call it arabic because the arabs got it from india particularly arabs at the beginning of the arab period in the eighth century. And recall the arabic numbers. But they got them from the indians. The greeks did not do very well in arithmetic. May develop geometry to a very high level but they learn arithmetic such as it was from babylon, and based on powers of 60 rather than powers of 10 which makes calculations harder. But neither the greeks nor the arabs nor the western nor the europeans at the time of the scientific revolution i think were taking indians or chinese as models for how to do science. Thats something that developed painfully and not systematically systematically, especially among the hellenistic greeks and then was revived in the scientific revolution. So my book in fact i even apologized at the beginning and say Oswald Spengler would hate this because its so eurocentric. But i think you have to be when youre talking about science and, of course, theres a hold of the of astronomy among the mayans wanted to talk at all about because they were completely cut off from europe and didnt have anything like the scientific revolution. Its a very good question because thats one of the things that historians look for is is not being eurocentric, and i am eurocentric. Yes. Victor, you had your hand up for a while. I just want to follow up on that first question about outer beyond the what about you for the big bang . It is expanding but was all compressed into one matter and not it is all expanded with any ideas about they are we dont know. We can trace with a lot of confidence, we can trace the history of the expansion of the universe back to what looks like about a hundredth of a second after a moment of temperature and density. And lately through the development of a series called the series of efficiently can trace back much closer to a mathematical beginning. But whether that mathematical beginning is a real beginning or just a place where our theory breaks down, we dont know. So about the very history, a very, very early history of the universe we operate a good and i dont have a good answer for you. I know about you through the list of faculty at the university of texas and i know from that batch are interested in particles and interested in unification of fundamental interactions. Yes. That interests me very much because i think the interactions that you are talking about are interactions of particles that form our Building Blocks for Something Else that builds up in Building Blocks to advocate to atoms and molecules and organs and organisms and so on and so forth. I wonder, you asked a question thats listed in dr. Jensens book on kinnaman dreams and realities. You asked is there anyway we can learn to define realms that intuitions derived from life on earth come from intuitions from that, are inapplicable to the realms that you are describing or would like to describe . Have i stated that correctly . I think i have. I think its a fair question. The esoteric, that is the description of nature in terms that are not intuitive but that take you beyond ordinary human perception is a very attractive idea, and it goes way back to greek times. For example, well to thales visit everything is water but more deeply much of my by plato who gave arguments that nothing ever changes. Certainly not what it appears to be true. And it contradicted other greeks visit everything is always changing. The greeks perhaps deserve great credit for being willing to look beneath the surface of things but they never took the next step up explaining why, why although they have these theories that are so counterintuitive, nature looks the way it does. And they think there was a strain of intellectual snobbery especially in the hellenic period until the death of aristotle. You dont find this in the hellenistic period starting around 322 b. C. When the center of greek thought moves from athens south to alexandra. But in the hellenic period, theres a snootiness about appearances. Appearances are not worth considering. Whats worth considering is the truth based on pure reason. It got nowhere because you cant understand the world just by thinking about it. Today, our theories are increasingly esoteric. That makes it hard to give public lectures about them. [laughter] but they are always accepted and, when they are accepted, only because they are validated by observations which we can actually see whats going on in the laboratory. We can count in a tiger counterpart or observe tracks in the bubble changer chamber. Even though theory involves things we can even imagine, it makes protections about things we cannot only imagine but measured. And that is a large part of what the difference is between modern science and the ancient world. I think one of the great developments in human thought has been the abandonment of the greek snobbery. When biologists want to study the nature of chromosomes or the nature of nerve impulses they dont study eagleson lines as noble beast, but they study squids and fruit flies because those are the most useful for getting to the truth. We may be still guilty of some snobbery. We may be ignoring opportunities opportunities, but i dont know what they would be. I think thats been pretty will work out of our systems. Do you have a question . Yes, over here. Let me compliment you. I read the book last night. Let me compliment you. [laughter] it is inordinately readable. I read it on my kindle and for addressing the god question headon, and for the way you defined it evolution. Thank you. Thank you very much. Other questions just like that when . [laughter] just like that one. Spent some time to go at a tactic texas book festival usage of given up on the conflict of science and religion after one thing perhaps this should be a dialogue. Im wondering, given the resurgence of religious fanaticism around the world and simple once in this atlantic cover story just in march about isis would argue they have a sacred duty to kill people for the utilitarian purpose of terrorizing a good else into surrendering them to the more quickly. I think it would be worthwhile to stress as youve done the abandonment of the geocentric good, the bad of a centric view and the simple fact that they try to persuade people to use reason but simply to say reality and your own conscience should lead you away from these primitive savage barbarian world of these. A universe of 100 billion or maybe 400 galaxies absolute continuity of life for 3. 8 billion years simply falsifies all of these religious systems that people evolved and been naked and get sick of hundreds of thousands of years ago. Cycle you come back to this issue and not give up on it just yet. Theres a lot going on. I dont know that i give up on in this book. You know im no friend to religion and i used to take that issue very seriously. Ive mellowed out a little bit not that im more religious than it used to be if anything less. But i am no longer regarded as my responsibility to disabuse people of their religious views. I mean thinking that theres life after death makes them happier and facing death, who am i to take that comfort away . In other words ive given up missionary work. [laughter] so when the book i try without making a big argument about it i tried to describe as accurately as i can the relations between science and religion and all the publications. Because they are complicated. It isnt just a question of religion trying to suppress science or science necessarily destroying religion. One of the questions i struggle with is the death of science of creative science toward the end of the roman period of two the beginning of the byzantine period and the death of science, or at least the petering out of science in the islamic world after about 1100 or and there are some really striking examples of antiscience attitudes in both christendom and islam. At the same time it has to be admitted that scientists like newton were devoutly religious. He was not orthodox. He didnt believe in the holy trinity, and as a result he faced losing his fellowship at cambridge, and his professorship, until the king was induced to give him an exemption from having to swear belief in the trinity. But its a complicated story. However, i think its true that not in newtons time but in the century following newton at least within physical science science became thoroughly nonreligious, which i to say antireligious but religion was just driven out of consideration of physical science. And this i think is responsible for the enlightenment. In fact, the historian trevor roper once remarked he thought it was a success of newtons theory that led to the end of burning witches. And today my impression is looking at it from outside which i do that modern jewish and christian religious people dont really care that much about the conflicts between literal interpretation of scripture and what is discovered by science. I mean there are some people who are offended by the theory of evolution but most of the people who i know have identified themselves as religious dont really find that a problem. And as i interpret it its the great withdrawal. Religion in the west has withdrawn from the position it once occupied provided an alternative to science as a theory of the real world or it has retreated if you want to call it a retreat come into a theory of things of the supernatural god the afterlife and so one, a system around in public most important for most people, a system of ethnic identification. This hasnt happened so much in the islamic world and islam today seems to me very much like christianity before the scientific revolution. With the same kind of persecution of aviation, the same kind of war between the war between shiites and sunnis it seems to me a recapitulation of the wars between the protestants and catholics. They just havent grown up. I dont say that in the book last. [laughter] another question . Time for one more. Yes. Im excited about this opportunity to ask a question that is conducting again and again. You will probably be to answer pretty quickly but to facts or two observations ive made in my armchair understanding of physics. One is that its always been put to me that the wave equation and heisenbergs metric, mechanics or mathematics are essentially equivalent. But at the same time for some reason it seems as if heisenbergs accounts would work is always almost always progressing more significant for some reason. Is about not know. I dont agree with that. In fact, when physicists started to use this to solve problems, the simplest atom, the Hydrogen Atom was solve he wasnt smart enough to do. A great genius was able to use heisenbergs theory to find the energy level of hydrogen. No one has ever been able to use his these to do