Transcript from Epic of Evolution: Life, the Earth and the Cosmos

1/19/2000

UG: My name is Ursula Goodenough. I’m a professor in the Biology Department.

CB: I’m Claude Bernard from the Physics Department.

MW: And Michael Wysession, Earth and Planetary Sciences.

UG: So as you probably all figured out this course has a single numerical name, namely 210, but it’s coming out of three departments. So Biology 210, Earth and Planetary Sciences 210 and Physics 210 are the same course and so we will probably be referring to this in a lot of places as just BEP 210 which stands for those three things just so that there’s something in front and it doesn’t really matter which one of those three you registered for because it’s the same thing. So this is a new course and we’ve needless to say tried to coordinate a course with three instructors plus a T.A. which means that immediately I need to introduce Heather Morrison. Say who you are.

HM: I’m a graduate student in philosophy and I’ll be running your discussion sections.

MW: And we have a grader.

UG: Oh, yes, I’m sorry, this is off to a good start here.

VS: I’m Van Savage, I’m in physics and I’m just going to grade the mid-term and the final and also if you have questions after class you could ask or something.

UG: Okay, so we have divided up what we are going to say here. I’ve already completely messed it up but let’s hope that we can continue better as we go along. And what I want to start out with just the story of how this course got going. So the story of how this course got going really has to do ultimately with what has happened to our scientific understanding of nature in the last I’d say 20 years. So before those 20 years up until quite recently science was a series of disciplines and there were geologists over here and there were biologists over here and physicists also coming in with a lot of understanding and that, once you understand something then that generates a whole lot more ways to understand so everything’s gotten very active. But about 20 years ago it started to become clear that the whole thing was more than just these pieces, that the whole thing made sense in a coherent kind of way. That there was a large meta version of what has happened from the beginning of the universe until the present and there’s a very famous biologist that some of you may have heard of, E. O. Wilson, who’s written a lot of books and he actually coined the term, “the epic of evolution” for this large understanding. So we called the course the Epic of Evolution for that reason but we also called it the Epic of Evolution because in fact it turns out that about 5 years or so ago I joined up with a philosopher named Loyal Rue and we put on a conference which we called the Epic of Evolution where the deal was that a bunch of scientists came and told this story, this understanding, in various ways to an audience of conferees who were largely non-scientists. And then we had philosophers and religionists and other people comment toward the end of the week on the meaning of this story, how to relate to it with the sort of meta premise being that all philosophical systems, religious systems, large understandings, have a core kind of a story to them. So in particular at that conference we were asking what are the philosophical/religious potentials of this large story compared to other large stories that have come down to us in various cultural contexts. So we put on this conference and we needed a geologist and I had gotten to know Mike here and he agreed to come and do the Earth part of it and I did the biology part and we had astronomers and other people doing this and it was a great conference and at the end of it Mike and I said gee, it would really be cool to do a course like this for non-science majors at Wash U. And so we talked about a little bit and we said, well, it would be great but we really need a physicist and neither of us knew any physicists and so we just kind of put it on hold. The next thing that happened was that I actually wound up being so interested in this that I went ahead and wrote a book called “The Sacred Depths of Nature” and in which I just covered the biology part of the story and really just a subset of that. And there is something called The Ethical Society of St. Louis which invited me right after the book came out to do an adult ed. series talking about the book and Claude Bernard showed up at that. Actually I sort of knew he was on campus and in fact the fun thing about Claude and me is that I knew Claude when he was your age so I knew him when he was an undergraduate in college and I was on the faculty of that college and so we go way back but there was about a 20-year hiatus and all of a sudden we discovered we were at the same campus. So Claude came to this adult ed. job that I did and he was really clearly interested in what was going on and all of a sudden I realized hey, wait a minute, we’ve got a physicist. And so I asked him whether he would be interested in joining Mike and me in developing a course that we’re now doing and he said yes so then we had no excuse but to do it. The Epic of Evolution conference that started this all off had just religious and philosophical responses to our understanding of nature to the epic and we’re certainly going to have that be one of the ways that we’re responding to it in this course, but we’re also really opening it up in general. The real thing that we hope will happen in this course is that as we tell of this epic, as we bring it to you, that you will sort of by the end of the course feel comfortable working with it, feel comfortable sort of feeling at home with it, and can bring that understanding as well to your understanding of political issues, environmental issues, all the other things that you will do as you go through your life. To that end. and we’ll be talking more about this with other people, we in particular have designed these discussion sections that we will have to be the place where you talk about the meaning of it and there’s also a term paper where you will have a particular opportunity to do that in a very detailed kind of way. We’re assuming that most of you are not science majors otherwise why you take an A course, right? But we don’t rule out the fact that there’s some of you here who might be freshmen who still haven’t decided, etc., or scientists who just decided that they would be interested in this larger approach to the discipline anyway. But we assume that most of you are not science majors, presumably a lot of you just because you happen to have talents and interests in other fields but it may be that at least some of you, let me be conservative, also found that you’re K through 12 contacts with scientific explanation were let’s say less enthralling than some of the other things that you did. And this probably has a lot to do with the struggles that are going on in our education system right now to figure out ways of presenting this in a way that makes it interesting to everybody. But your experience may have been, somebody described her year of high school chemistry as a year of struggling with a Bunsen burner. You may not have been terribly interested in watching balls rolling down inclined planes or learning the parts of a leaf or whatever. This all may have just not interested you. It may be that the way that we present this epic of evolution won’t interest you either but we can assure that it’ll probably be different than the way you’ve heard it before. We are going to not focus, even though this is what we all do ourselves as scientists, we’re not going to tell you which scientist made which discovery. We are not going to give you a lot of data about how the experiment was done and what hypothesis was tested, etc. We’re going to really try to tell it to you as narrative and I think that that will be a different kind of an approach than you’ve had to it before and we hope it will be interesting. So to the best of our knowledge this course is an experiment. I don’t think anything like this has ever been tried before. We’ve certainly never tried it before and what we would really like is to have it be something that you all sort of actively participate in, give us a lot of feedback, sort of get into it and we can all see how good a go we can make of it.

MW: I think one thing to keep in mind with this class also is how you unique this endeavor is. Throughout your whole educational system, your whole educational history, you have learned things in compartments, which doesn’t really make a whole lot of sense because there’s only one world and yet we have our chemistry and we have our physics, and we have our philosophy, and we have our history. And this whole university and all universities are really good at breaking things down in little pieces and there’s not a lot here if you look through the course description that puts things together. I think largely because it’s a lot harder to do and partly because the people teaching the classes are all experts on particular things. I mean I’ve spent the last 10 years looking at the boundary between the Earth’s core and mantle. This is my sort of niche in the realm of research. It’s not going to play a major role in most people’s lives. However, to really appreciate our world we need to be able to step back and piece it together. All of us have dealt with aspects of change and evolution of our world in various ways. Obviously biology is filled with evolution in various ways. I teach a class in the Geology Department called Evolution of the Earth. There’s at least one person in here who’s taken that class. And in there I try to touch on the Big Bang and evolution of the universe and I try to touch upon the origin of life and the evolution of life but I don’t know those sides of the story very well so I do a lot of faking it. What we’re trying to do here is get three people from different fields who understand the stories within their areas and put them together and try to give the story of our universe, of our world. It’s obviously going to have an extremely anthropocentric view in the sense that we’re going to be most interested in the line of history that leads up to us. So I’m not going to spend a lot of time about the surface of the planet Pluto. I’m going to spend more time on Earth because that’s where we live. Not to say that Pluto might not be very fascinating but that’s just not going to be relevant to us. And likewise with biology I’m sure Ursula is going to spend a lot of time on human brains and development as opposed to some other creature. So there’s going to be that bias there. Obviously we can’t do the whole universe in one class but we’re going to try to do a large part of the universe in class. So that alone was actually scary to many of colleagues in my department. When I proposed this course a lot of them were like very nervous at the prospect of having the course that covered three different departments even though we’ve actually made some strides in our department and we actually have for instance a course called Bio-Geo Chemistry. I mean we’re recognizing that to understand certain systems we really need to cross boundaries between different disciplines. However, we thought what the heck, let’s shoot for the moon and try to do everything and in the discussion sections we’re going to put in history and literature, and culture, and religion, and philosophy. Obviously in 14 weeks we’re not going to cover everything but I think if you take anything from this class it’s the understanding that there are connections and bridges between everything. Everything is interconnected in terms of the history of our world, the different disciplines, the thoughts or views. As broad a picture as you can get of these things the better understanding and hopefully I think appreciation for the world you can develop. So that’s sort of the goal from where I see it.

CB: I’ll just add a few words. I think Michael and Ursula have really expressed the general philosophy of the course. I just wanted to say a few words about where I’m coming from as a physicist. My training and my research are not in cosmology, which is the subject of this course, but in elementary particle physics. I spend my time thinking about the smallest things, quarks in particular, which make up protons and neutrons. Although I’ve followed cosmology to some extent, I wasn’t really paying attention to what was going on in the field in great detail . So when we decided to do this course I started to read and the more I read the more excited I got. It’s amazing --- I think it’s really fascinating --- how the very smallest parts, namely the physics of particles and nuclear physics, fundamentally affects and is affected by the biggest things -- the Big Bang and the growth of the entire universe. And the interplay between the smallest and the largest is going to be a recurring theme in what I’m going to be talking about. For example the nuclear processes that occurred very early in the history of the universe during the time of the Big Bang and the nuclear processes that take place in the center of stars are what forms the elements that the Earth and living creatures are made out of. Carbon, oxygen, nitrogen, hydrogen, etc. were made primarily in stars out of the products of the Big Bang. The stars then exploded and sent material into the interstellar dust, which then condensed again into other stars and into our solar system. And eventually those atoms, which were created inside of stars, became part of you. So we’re part of the whole universe actually, and our stuff really is part of this whole story. And the more I learned about it and the more I read the more excited I became about doing this course. It’s really an awe-inspiring subject. The formation of the universe, the formation of the Earth, the formation of life, and the evolution of life help explaion why we are what we are. And I’m really excited about it, and I hope that you guys will also get excited about it.

MW: You want to start in on the syllabus?

UG: Nuts and bolts.

CB: Okay, nuts and bolts. Does everybody have a copy of the syllabus? Let me just go through it. There are a lot of things I don’t need to say that are on here that are just self evident. As we said, Heather is going to be running the discussion section. But at least one of the rest of us, the three professors who are involved, will be at each section but we’re not there to lead the discussion section. That’s Heather’s job. We’re there as a resource if issues of science come up. For the rest, we will participate but not be leading the discussion. Here’s the contact information.

About the Web site: I discovered a peculiarity of Microsoft Word here. Whenever you put in a Web site it automatically underlines it as if it’s a link. But in underlining it, it goes over the underscores in the phrase “epic_of_evolution,” so between “epic” and “of” and “of” and “evolution” there should be underscores, which is the capital hyphen on your keyboard. What we’re going to be putting on the Web site are first of all transcripts of the lectures. We’re taping the lectures and we’re going to edit those and put them on the Web site. There’ll be some delay between when we give the lecture and when it actually shows up, maybe a week or so. I don’t think the transcripts will be substitutes for attendance because they won’t have all the visual aids, they won’t have the slides, the videotapes, etc., but I think they’ll be a good way of reviewing and figuring out and checking on things that you missed or didn’t understand at the time. The Web site will also have lists of study questions, just basic questions about the lectures that will help you in organizing the knowledge. Some of those study questions will probably appear on the exams. There’ll also be reading assignments. The idea is that you’re going to be reading along in some of the required books with the lectures and you’ll finish each group of readings by the time we get to the discussion section for that group. Next week’s discussions are a special case because we’re going to only have one real lecture --- on Friday --- before that. So I’m going to be lecturing on this Friday and then all of next week about basic cosmology. And then the following week, the week of January 31st, there’ll be discussions that are in some sense based on those lectures. The first reading assignment should be completed by that time. I didn’t want to overburden you today, but I’ll hand out the list of reading for that first block on Friday.

UG: Can I interrupt right at this point? One of the things I should have said, maybe it’s obvious in here somewhere, which is that in addition to, one of the ways that we’re going to try to integrate the story is that we are lecturing sequentially, we have a round robin. So Claude is going to do three lectures on cosmology, the following week he will be in discussion sections working with you on that material along with Heather and meanwhile in class Mike is going to be telling you about the Earth. And then the next week he will be in discussion section and I will be telling you about biology. And after I have three times of biology Claude will come back in. So we decided that that was the best way to integrate it and keep it going and so that you wouldn’t get a whole bunch of physics and then a whole bunch of Earth and then a whole bunch of life. But it’s going to keep coming at you. To the extent that this is confusing we want to hear about that but we also hope that confusion will also mean that you’re not just thinking about these topics as three separate entities but trying to keep bringing them together.

UG: And in fact more to that point, at the end of each group of lectures so typically on the Friday we’re going to pass out a little sheet that asks for your comments, questions about what happened in the lectures, things that you would like to discuss in the discussion sections and we’re going to use that as part of the basis for what the discussion sections are going to be about, and also just for feedback about the lectures to see if we’re hitting the right level -- if it’s too easy, too hard, whatever.

CB: Okay, what else should I say here? The course requirements are listed at the bottom of the first page and the top of the second. The breakdown of the grade is 10% for your participation in discussion, 20% on the midterm, which is March 17, 30% on the final exam and 40% on the term paper which we will discuss a lot more detail in the section next week. In fact that’s going to be one of the main things to be discussing in the section next week because we won’t have had a significant number of lectures yet. Heather will talk about the term paper and how the project is going to be organized and what kinds of ideas we’re going to be looking for in that paper. I also listed all the books that we put on reserve. They’re in the Biology Library, which is in the Life Sciences Building. The first six here are the books that are required books that we’re going to be assigning readings from, and those are also the ones that are on sale at the bookstore. They’re all paperbacks so the expense won’t be that much. There are a few recommended books, which are also closely related to what we’re going to be talking about, and then a lot of other useful books that we put on reserve also. Some of the books in the list are starred. That just means that we put them on 2-hour reserve. They’re reference books, so we want them not to stay out for long because a lot of people might need to look at them. The other books, which are for further reading and maybe thinking about paper topics, can go out for 2 days at a time.

The main book that relates to what I’ll be lecturing on is the book called The Whole Shebang by Timothy Ferris, listed on the second page of your syllabus. I like the book because it’s well written and it’s generally clear. On the other hand, Ferris is not a scientist; he’s a science writer. Once in a while he doesn’t get the science completely right and sometimes he’s sort of right but a little confusing. So what I decided to do is to keep, also on the Web, a list of corrections and footnotes to Ferris’ book to fill in the gaps and to correct what I think are possible misconceptions that the book might give you. All the rest of the ones that I put on the recommended or useful list are by scientists and they have the advantage that what is in there is pretty much correct. On the other hand, they have the disadvantage that they’re not very well written and it’s hard to understand if you’re not a scientist already. Some of the books I loved, but I don’t think they’d be very good for learning this stuff to begin with --- they tend to implicitly assume a lot of scientific knowledge, which you’re not expected or required to have for this course.

Then finally in the syllabus is a list of our lectures. As you see and as Ursula was just saying, we’re alternating a week at a time on each of these different subjects in the hope that it will help to tie it all together. It’s all part of what brought us here and made us what we are. Hopefully this interweaving will help you see that and make it more exciting for you.

Okay, any questions about the syllabus? [Q: So the first week the discussion section will meet will be next week?] Yes, the discussion sections will start next week and those discussion sections will be primarily about getting you started on thinking about the paper. Although if you have questions about my lectures by then, you’re certainly welcome to ask or even bring up other issues. So that’s next week. Then the week after that will be the first set of discussions that are based on lectures. For that second week, which would be the week of January 31, you’re supposed to have completed the first set of readings so that you can have a basis for discussion.

MW: I’ll just mention a couple things. So in the syllabus we don’t list when the readings are due. What we will do though is keep you posted as the course goes through and as each one of us prepares for our turn at running the lecture we will assign the readings due for that. I will mention that if you’ve picked up the books already you’ve seen that the reading list is different from most reading lists you’ve seen for a course. For instance, the two books that I have in the required books is Tales of the Earth which is a book written both by a scientist and a science writer which is a compromise means that the writing is sometimes not very good and there are still lots of errors. But it’s actually one of the best -- there aren’t a lot of good books in my field that sort of talk about the story of the Earth in a non-technical way. One other book that I would recommend if you’re interested in reading more on sort of the history of the Earth in non-technical jargon is a book called Naked Earth by Shawna Vogel and that’s listed in the reference. The other book that I have on the required list is totally fiction. It’s called Cosmicomics by Italo Calvino and it is one writer’s view of the history of the Earth and somewhat of the universe as well. It gives you some idea of how the story of the evolution of the universe can inspire someone to view it in a slightly different way. So in terms of what we expect from you in the class, we expect the readings be done. I think that would just enhance your enjoyment of the class and also will allow you to participate to a fuller degree in the discussions. We do expect participation in discussions as Claude mentioned with the fact that that’s 10% of the grade. We do expect that on Fridays that you do these short little questions, and the questions will be sort of threefold: 1) What facet of this week’s lectures did you find of particular interest? 2) What facet or facets of the week’s lectures did you find most confusing or challenging? 3) And lastly, we request that you offer some question or concept related to that week’s science that could be a good topic for discussion the following week. So in other words we have some ideas of what we would like to do in the discussion sections but we’re very open to suggestions from you as well so if the lecture is on some aspect of the Earth and I talk about flooding and you happen to know a lot about mythology and how almost every culture has a flooding myth and you want to talk about how maybe flooding has affected, sort of created the early mythologies of civilizations, great! Write it down. That would be something that we could touch upon. I’m just giving one example but we’re certainly open to that. So during the lectures keep in mind those three things -- what’s really interesting, what’s confusing, and what would you like to pursue in a broader context. We will try to have transcripts of the lectures made available on the Web. There are a couple reasons for this. The main one is that there are no textbooks that will cover what we are covering and we could each require several complicated textbooks for you to read from our fields in order to cover this material but it would be at a level that would be far too complex.

UG: And it would cost you $300

MW: Well, at least. What we will try to do is have that information available to you. However, there’s going to be a real turnaround lag. In other words it won’t be available to you by the time Monday discussion comes around so it’s still important for you to take your own notes but don’t obsess about taking all the little details down because most of those details will be there. Focus in the lectures on understanding the concepts that we’re talking about because sometimes that doesn’t come through as well even if you read it on a page. And also another problem with the transcripts obviously is the visuals that we would show in a class aren’t going to be on there as well. So you may want to as you take your notes comment on whatever slides or visuals that we might show as well. Ursula, do you want to talk a little about sort of overview of life maybe?

UG: Oh, okay, well, let’s let Heather at least, do you want to say anything?

HM: Just a few brief words. We’re going to talk a lot in our first discussion section next week about the paper and things like that so don’t worry about that just yet. You’ll have an entire handout on the details of what you’ll need to do with regard to that. One thing that I do want to mention though is that this discussion section is I think a rather unusual feature. Science courses typically have labs. This one has a discussion section so I don’t remember who mentioned the details of the Friday questionnaire but in any case this is going to be really important for motivating our discussions. Put some time and energy into thinking about what things you really want to talk about in these discussion sections because you have a lot of control. We certainly have things that we do want to discuss but we’re giving you an opportunity to influence that fairly significantly so do devote some time to thinking about what you want to talk about in the next week.

UG: Let me just add to that. The way that’s going to work is that on Friday you guys all scribble your stuff down. Heather’s going to collect them, go through them all for what she thinks are the most interesting three questions or whatever that come in. You won’t sign these things so you don’t get any points if your topic is chosen. Even if your topic is chosen it may be that seven people suggested the same thing but you can take credit for it anyway in your own heart. And then she’s going to sort of run her picks by whoever it is that week of us that’s going to do it and so we’re all on the same page on it. And then those are the topics that will be talked about in all three discussion sections the next week. Let me just say a word about the paper because in case some of you are in here sort of, you signed up for another course and discipline and you’re trying to figure out what you’re going to drop and you haven’t yet heard about this paper thing. It seems like maybe we shouldn’t be coy about it since it’s 40% of the grade. What we’re going to ask you to do in the paper and we have much more specific articulation of this is to take some aspect of this narrative, this epic of evolution, focus on understanding it more deeply than we can obviously do in the survey so there’s a very important piece of the evaluation of this paper and your experience of working on this that will involve just really getting to know the science in that particular thing that you’ve decided that you’re particularly interested in. But then the other part of the paper is to somehow take that and relate it to something else that you do or are interested in -- history, art, religion, philosophy, environmentalism, whatever. We have a whole larger sort of description of this that we’re going to give you in sections but that’s the idea, is to work with this material in some other context and bring it together and experience yourself the whole activity of being at home in it. We decided that we were going to kind of talk about a 5-minute overview of what it was that we were going to talk about. You gave a little bit of an overview already. Was that your overview or do you have another overview?

CB: I think that’s enough overview. I’m ready to get started.

UG: All right, Mike, give your overview. I’ll give a tiny overview and then Claude can take us out of here.

MW: I think the striking thing from the Earth side of this story is if you look at any other planet it’s totally uninhabitable even in the nearest planets, Mars and Venus, don’t seem to have any evidence of life despite the faces of Mars that you’ve seen on the cover of National Enquirer. Why is this? Are there any other planets out there that have life? That have the conditions that would allow development of a creature like us? Earth is unique in our solar system in another sense, in the sense that as a planet it is very much -- we use the word “alive.” Obviously it’s not alive but it’s very active. It is not static at all. If you could view the Earth sped up it would look like the surface of a pot of boiling soup or coffee. Our surface is constantly being consumed back into the planet, heated up, melted, twisted around. The surface of the Earth, what we call broken into plates, you’ve probably heard the term “plate tectonics.” The continents bounce around all the time, bang into each other, push mountains up, sink down beneath the edges of other continents. It moves slowly and it moves at the rate that your fingernails grow, inches a year. So to us it looks like it’s static, it’s solid. There’s the Earth and this is how it is, and this is how it always will be. The hardest thing for geologists to do, I think what makes a geologist is the ability to think that a million years is a rather brief period of time. Now of course our worries and our struggles over our incredibly brief life span somehow seems a little less stressful and important when you look at it in those terms but if you could think of the Earth as a process that has spanned 4.55 billion years, which is the age of the Earth, then you can see that over this time you’ll see that the Earth has constantly changed very dramatically and we forget this sometimes. There were eruptions of volcanoes within recent times geologically in places like Arizona and Wyoming that covered the whole continent with ash and would destroy much of our country were this to happen again today. And these are still active volcanoes geologically speaking. They won’t happen during your lifetime and they won’t happen during the lifetime of your children’s children’s children’s children. But they may happen somewhere around the world and things similar to it. The example that I love to give in my Evolution of the Earth class is how your history books are all wrong, in that what caused the French Revolution was a volcano. There was a tremendous amount of volcanism in the mid 1780s and it totally altered the climate for a period of years. Winter had the coldest, wettest winters and seasons that it had had in a century. Crops failed. About a dozen governments fell in Europe because people were starving and rioting, and you can point to all sorts of political factors involved with the toppling. You know the storming of the Bastille and all the politics there but none of it would have happened if it hadn’t been for the eruption of actually two volcanoes -- one in Iceland and one in Japan. And these sort of connections I want to build in places in the course. And that’s one aspect on a very short time scale but over a long time scale we have a unique planet, different from any of the others in that we have the atmosphere, an ocean and a surface that can support life and it’s due to the fact that it is continuously active and bubbling over. And so if you can get that sense at the end of the class that what we live on is a vibrant, active planet that’s constantly in motion then you can consider yourselves to be geologists.

UG: So all I want to say is that I’m going to be talking about life. Obviously I have the easiest assignment because life is about evolution but I just want to say that the reason that this whole thing can be called evolution is of course evolution has the sort of trivial meaning of change, of something going from something to next and how anything changes depends on what you started with, what you had before the next thing happened. And so the extent that we’re talking about evolution we’re talking about evolution even though on these very different time scales and thinking about very different phenomena they are all evolving, they are all changing. And the one thing that I will hope to have you guys really thinking about deeply is that with biological evolution there did come in a different game, and the different game is that in biological evolution you also have these instructions so that you can remember how to do something. So if a volcano erupts that changes everything and there’s evolution of the planet follows but there’s no memory per se about that volcano. You can’t sort of go back and rerun it and get it to go again, and the volcano doesn’t have offspring. So the dynamics of the evolution of life include the fact that there are these instructions and the way it works then is quite different because what happens is you change the instructions, you change the result and then it’s ultimately the environment that selects whether that new result is one that will continue through time and spread or whether that new idea is a terrible idea. So that’s the major thing about biological evolution that differs from these others. And let me just say that there’s a fourth kind of evolution that we’re not covering in the course which is of course cultural evolution. Once you got humans and they started having cultures then those cultures themselves have evolved. We’re going to be talking almost nothing about that. If we have a fantasy it is that this course could someday be coupled with a second course called The Evolution of Culture and we’d make all the scientists take it.

CB: Okay, so let’s get started. We’re going to be talking about the evolution of the entire universe. We may have to refine later on what I really mean by the universe but I’m just going to ignore that issue for the moment. I guess what I’m really talking about now is what we see out there, the observable universe. And maybe the most striking thing about the universe is it’s big, it’s enormous. Let me just try to give you some sense of how big the universe is. The Earth itself that we live on is 25,000 miles in circumference. [I’m going to be saying a lot of numbers. Don’t feel like you have to know all these numbers. If there’s some number that I think is particularly important -- there are a few now and then -- I’ll write it on the board. I just want you to get the general idea here. You’re welcome to write down these things, but I want you to get the picture more than the numbers.] The Earth is 25,000 miles in circumference and that’s a pretty big distance. Few of us have actually done that trip, but the distance to the moon, which is our closest neighbor, is 10 times that amount, about 240,000 miles. And the distance to the moon is so big that it takes light, which goes incredibly fast, a little over a second to get to us from the moon. And so in fact when you look at the moon you’re not seeing the moon as it is now. You’re seeing the moon as it was a second ago. And the moon is of course the furthest people have been. The Apollo Moon Missions sent people to the moon.

Beyond the moon we have the nearest star, and the nearest star of course is the sun. I hope you know the sun is a star. The only reason it looks so big and bright in our sky is that we’re close to it, relatively speaking. It’s a pretty ordinary, average, run of the mill star but we’re close to it so for us it’s important. When you take the big picture it’s just like many, many other stars. It’s about 400 times further than the moon, and light takes about 8 minutes to get to us from the sun. So again if you look at the sun you’re not seeing the sun as it is now. You’re seeing the sun as it was 8 minutes ago because of that time that it takes light to get to us. So in fact if the sun were to blow up right now -- it’s 3 minutes to 3 -- we wouldn’t know about it until 5 minutes after 3. You’d be out of the class by the time you found out. Luckily we know enough about solar processes and what makes the sun shine. So that I can assure you that the sun is not going to blow up now or anytime soon. It probably has on the order of another 5 billion years to go --- so nothing to worry about. But again we’re seeing it in the past when you look at it --- although only 8 minutes ago.

Now the second nearest star to us, in other words the nearest other star aside from the sun, is a star called Proxima Centauri, and that’s about 24 trillion miles away. Maybe I’ll write that number down, not so much because I want you to know it but just so you can look at a number that big and give you some feeling of 24,000,000,000,000. A trillion has 12 zeroes so that’s the distance to Proxima Centauri, 24 trillion miles. It takes light a little bit over 4 years to get to us from Proxima Centauri. And so again, if you look at Proxima Centauri you don’t see it now. You see it as it was 4 years ago. To give you some sense of how far this is --- remember it’s the closest star aside from the sun --- consider this: An Apollo astronaut riding in one of those Apollo rockets travels at fastest about 25,000 miles an hour. That is pretty fast, a lot faster than a jet airplane, which travels about 600 miles an hour. If you got on that rocket and headed out to Proxima Centauri at 25,000 miles an hour, you would arrive there in approximately 100,000 years. [It’s an amazing distance and just gives you some sense of the difficulties if you start to imagine what it would be like to have space travel. It’s not something that’s going to happen easily if it ever happens at all.] So it’s very far, 100,000 years at Apollo astronaut speed. And if you stood on Proxima Centauri and looked back at the moon going around the Earth, the apparent size of the moon and the Earth system would be the same as the apparent size of a thumbtack from 400 miles away. And in fact these distances start getting so enormous that miles become a bad way of measuring distances because you end up writing a lot of zeroes. So we start measuring distances not in miles but in light-years. A light-year is the distance that light travels in one year. It is sort of an important number. One light-year is about 6 trillion miles or 10 trillion kilometers. And so the distance to Proxima Centauri, about 40 trillion kilometers, is about 4 light-years. Okay, I see it’s now 3:00. We still have 5 minutes before the sun is going to explode and I’ll stop lecturing.