MEASURING THE UNIVERSE

August 19, 1999
		David Gergen, editor-at-large of U.S. News and World Report, talks with Kitty Ferguson, professional musician and author of Measuring the Universe: Our Historic Quest to Chart the Horizons of Space and Time..

Aug. 3, 1999 Dialogue with Lionel Tiger, author of The Decline of Males July 22, 1999: Elizabeth Drew, author of The Corruption of American Politics. Aug. 16, 1999: Dialogue with Adam Nagourney and Dudley Clendenin July 8, 1999: Dialogue with Bill Shore of Share Our Strength. July 23, 1999: Dialogue with Professor of Physics Freeman Dyson. July 13, 1999: Dialogue with with New York Times columnist Thomas Friedman. Browse the NewsHour's coverage of the Science and Gergen Dialogues.   American Association for the Advancement of Science Reviews by Amazon.com The Julliard School	ELIZABETH FARNSWORTH: Now, a Gergen dialogue. David Gergen engages Kitty Ferguson, a professional musician and science writer. She is the author of Measuring the Universe: Our Historic Quest to Chart the Horizons of Space and Time. DAVID GERGEN: The first question you must often get is, how is it that a graduate of the Julliard School of Music has come to write a book about astronomy? KITTY FERGUSON, Author, Measuring the Universe: Well, I guess I could say that Julliard had a fantastic physics department, but that's not the case. I think to understand that, you have to go back to my childhood. And my book begins with a story about how my father took my brother and me out when I was nine years old to measure the height of the windmill on my grandparents' farm. And this was a huge adventure. Both my brother and I had all sorts of ideas of how we might do this, very complicated ideas. But what my father taught us was very simple, and I was positively elated when we had done it. I felt that we had somehow outwitted that old windmill without even touching it. We measured its shadow, and by measuring its shadow, we learned its height. And this was not an isolated incident in my childhood. My father would we sat at the dinner table, he would rearrange the salt and peppershakers or the butter to explain how the planets orbited the sun, or how the electrons move around an atom. And I grew up -- because he was a musician. He taught music in the schools. He was not a mathematician or a scientist. But I grew up thinking there was nothing odd about somebody who was a fine musician also having this passion for science and math. And I also grew up thinking of science and math not as something necessarily you had to do for a living, or that you had to do in school, or that a bunch of other people did that didn't include me. It was really something for an adventure, a summer outing. And I think that feeling has stuck with me through my whole life, even though -- maybe partly because I didn't take that much math and science in school. It was always a -- you know, a fun thing.
	The measure of shadows
	DAVID GERGEN: Well, that measuring of the shadow seemed to be so important to the very first scientists, even Eratosthenes -- KITTY FERGUSON: That's right. DAVID GERGEN: Living in the second century, before Christ. KITTY FERGUSON: Yes, that's right. DAVID GERGEN: Who was measuring shadows in Alexandria to figure out the circumference of the Earth. KITTY FERGUSON: That's right. And he's a good example of one of the -- my favorite themes in this book, which is the wonderful way that so many of these characters in the book, these people in the history of measurement, had of picking out the essential clue-- sort of Sherlock Holmes stuff. You know how the detective will come and say, "now we have all the information we need to solve this crime," and you as the reader say, "what?" You know, "I don't see that at all." Well, that's the sort of thing that we have so often in the history of cosmic measurement. For instance, in the case of Eratosthenes, he got this little trivial news that on the day of the summer solstice in Syene, which is down near where the Aswan Dam is, that at noon, sunlight hit the bottom of a very deep well. Sun shone all the way to the bottom of the well. Now, that to you or me probably wouldn't mean that much, nor would it have to most of his colleagues, most of his contemporaries. But he knew that was what he needed. He had at his fingertips then what he needed to measure the circumference of the Earth. And we find that again with, well, Cassini in 1673, when he measured the distance to Mars. He recognized that the moons that Galileo had discovered around Jupiter were going to be the clue -- going to provide the clock for that measurement. We have this sort of thing all through the history of what we call cosmic measurement, and I find that absolutely fascinating.
	Astronomers of the past
	DAVID GERGEN: The central point for so many astronomers for some 1,700 years was that man was at the center of the universe, the Earth was at the center of the universe, and that lasted right from essentially the ancient days right up until the 16th century. KITTY FERGUSON: That's true. There was somebody, though, living at the time of Eratosthenes named Aristarchus, who proposed that it was it was actually the sun that was in the center of the system, and that the earth and all the other planets orbited that. And that idea was not accepted in that time. There was really no reason for anybody to accept it then. There was no evidence that that was so. In fact some of the evidence that might have indicated it was so was missing. But we have to admit that he thought of it. This is 200 years B.C.. But yes, we did think we were the center of the whole thing. Everything revolved around us. DAVID GERGEN: That was the system that came from -- Ptolemy figured that out. KITTY FERGUSON: That's right, and earlier, from Aristotle before that, and then was really brought to -- I guess you can say, brought to a head with Ptolemy, because he managed to systematize everything into circles and spheres, and it was a brilliant achievement, his. We sometimes say, you know, Ptolemy was wrong, Copernicus was right. But Ptolemy's achievement was one of the -- just really the premier intellectual achievements of all human history. There's no doubt about it. DAVID GERGEN: Is it the coming of the telescope that changed our understanding that the Earth was no longer at the center of things, but rather the Sun -- the Earth went around the Sun -- the Copernican revolution?
	Re-thinking the universe
	KITTY FERGUSON: Well, the interesting thing is that Copernicus lived before the telescope, so that's not where he got the idea. And, of course, you want to know what suddenly happened, what was different for Copernicus? One of the things that was different for Copernicus was that the Ptolemaic astronomy by this time had become very cumbersome, complicated astronomy. And Copernicus was a good enough mathematician to be totally annoyed with this. It just wasn't -- also, Copernicus had a belief that a simpler explanation was much more likely to be the right explanation, and that was nothing new with him either, but he applied it to this plan or this systematization of the universe. DAVID GERGEN: One has the overwhelming sense in reading this history that for so many centuries, we like to believe that man was at the center, then we thought, oh, the Sun is at the center. And now we understand the Sun is part of large galaxy, and that the galaxy is one of many, many galaxies, and man seems less and less significant. KITTY FERGUSON: That's right. I mean, we -- when we first discovered there's five other solar systems, we felt very small, and the solar system seemed huge. And this was the end of the 17th century. Then in the 19th century, when we discovered the distance to the nearest stars, the solar system became tiny. I mean, you have to travel -- if you traveled from the Sun out to Pluto, you have to go 9,000 times that far to get to the nearest star. That's a lot of darkness out there. We've got this little cozy solar system, very isolated, in the middle of all this darkness, before we hit the next little outpost of light. But that was -- that seemed huge. Then we discovered, you know, the size of the galaxy, and the fact that this solar system isn't even the center of the galaxy, and then that the galaxy is only one galaxy among so many billions of galaxies, and that this -- the universe might -- there may be other universes. DAVID GERGEN: As the 20th century comes to a close, you say there are two questions: How old is the universe and what is its future?
	What does the future hold?
	KITTY FERGUSON: Yes, that's right. And I think we've come near to knowing now the age of the universe. There's still some controversy about it, but you have to admit that it's amazing even to be able to have -- to know enough to have a meaningful argument about something like that. The future also is -- depends a lot on what we call the value of omega. That's the formula for omega. And that is up in the air a little bit right now because of recent discoveries that the expansion rate of the universe seems to be speeding up, and what exactly that means. There's a lot of speculation going on about that. It's very interesting. DAVID GERGEN: So what is the future of the universe, and what's our best understanding? KITTY FERGUSON: We don't know. I mean, it could be that the universe will expand, and then will re-collapse into what we call a big crunch. That's probably not what's going to happen. That's probably the least likely scenario. The way it seems to be right now is the universe has expanded and will continue to expand at just the right rate so that it won't re-collapse. The other possibility is that it will expand and continue to expand so that it sort of thins out to thin obscurity. And the recent discoveries that the expansion rate is speeding up at first led people to believe, yes, it's going to continue to expand much faster and thin out. But I think that now that people have given it a little more thought, worked out the mathematics of it, possibly worked in Einstein's cosmological constant as another part of the equation, they've got it back to where we think what is called the flat universe, which is the universe we seem to live in, which is this one that is not expanding so rapidly that stars and galaxies haven't formed and haven't collapsed, but seems to be the exact kind of universe we need to produce life, which is very lucky for us. DAVID GERGEN: Kitty Ferguson, thank you very much. KITTY FERGUSON: Thank you.